Abstract Background In Tanzania, the roles of men and women are classified based on the local cultural context. While men are usually the breadwinners, women are traditionally responsible for most domestic chores. Particularly for malaria prevention, studies in Africa have revealed women as being responsible for daily up-keep of the net. Using social role theory, this study explored the role of men and women in net care and repair and gender-related motivation and barriers to net care and repair in Tanzania. Methods The study was conducted in the two villages of Ruangwa district in Lindi Region. The study applied qualitative approaches and carried out in-depth interviews and focus group discussions with men, women, women with children under the age of five, and village key informants. Results Mosquito nets were valued by all participants as a protection measure against mosquitoes. Study findings indicate that net care and repair falls under a woman’s daily household responsibilities. While men were said to assist in stitching damaged nets, washing dirty bed nets was regarded inappropriate for men and not traditionally accepted. Motivation for net care and repair was reported to come from both men and women; for a woman keeping the net clean defined a caring and responsible woman, while men indirectly promoted net washing when complaining about nets being dirty. Women reported that men could do everything that women do regarding net care and repair, but that it does not fit into societal norms. Conclusion With increased globalization in Tanzania, more women are becoming part of the workforce, which may limit their full commitment to net care and repair activities, leading to increased net damage, malaria incidences and higher costs for malaria treatment. The National Malaria Control Programme should consider incorporating research-informed gender-transformative messages into their behaviour change communication on mosquito nets and work closely with trusted Community Health Workers to inform communities about the importance of sharing responsibilities in net care and repair. It is acknowledged that changing people’s behaviour and practices is a long process, which will require a deep cultural and political shift.…

Abstract Background The rate of physical deterioration of long-lasting insecticidal nets (LLINs) varies by household practices, net brand and environment. One way to sustain the protection provided by LLINs against malaria is through day-to-day care, and repairing holes as and when they occur. To ensure LLIN coverage is high between mass campaigns and, as international donor funds decrease, personal responsibility to maintain nets in good condition is becoming more important. This study aimed to understand local barriers and motivators to net care and repair in southern Tanzania in a community that receives free LLINs through a school-based distribution mechanism. Methods Qualitative research methods were applied in a rural and peri-urban village in Ruangwa district. Focus group discussions (FGDs) were conducted for five groups of 8–12 participants; (1) key informants, (2) young men (18–24 years old), (3) women (> 18 years) with children under the age of five, (4) older men (> 25 years), and (5) older women with or without children (> 25 years). In each village, five men, five women with or without children, and five women with children under the age of five were recruited for in-depth interviews (IDIs). After each IDI and FGD with women with young children, participants were guided through a participatory activity. The study also counted the number and size of holes in nets currently used by IDI participants to determine their physical degradation status. Results A general willingness to care and repair mosquito nets was observed in Ruangwa district for the love of a good night’s sleep free of mosquito bites or noises. Net care was preferred over repair, especially among women who were the primary caretakers. The main motivation to look after nets was protection against mosquito bites and malaria. Washing nets occurred as frequently as every other week in some households to ensure cleanliness, which prevented other dirt-related problems such as sneezing and headaches. Barriers to net care included care not being a priority in the day-to-day activities and lack of net retreatment kits. Net repair was reported to be a temporary measure and necessary as soon as a hole was identified. However, during the net assessment and participatory activity, it became clear that people did not actually repair smaller holes. Protection against mosquitoes, malaria and cost saving from replacing nets were identified as motivators for net repair. Barriers to net repair included it not being a priority to repair holes that could be tucked under the mattress and lack of knowledge on when to repair nets. Conclusion In Ruangwa, net care was defined as overall net maintenance, such as cleanliness, and not directly associated with the prevention of damage as reported in other studies. Net repair was reported as a temporary measure before the acquisition of a new net, hence not a priority in a busy household. Inconsistencies were observed between reported intentions to repair mosquito nets and current net condition. Targeted education through health facilities and community change agents are potential means to overcome barriers to net care and repair.…

Abstract Background Targeting swarms of male Anopheles mosquitoes with techniques such as aerosol spraying could potentially suppress malaria vector populations and parasite transmission. Unfortunately, research on Anopheles swarming behaviours is limited, particularly in East Africa where only a handful of studies have been done. New evidence has recently emerged that such swarms are common even in Tanzania, where they could be readily identified and characterized by community-based volunteers, and potentially targeted for control. However, improved understanding of public knowledge and perceptions will be crucial for successful uptake of any interventions targeting swarms. Methods Explanatory sequential mixed methods approach was used to assess knowledge and perceptions regarding mosquito swarms among community members in Ulanga and Kilombero districts, south-eastern Tanzania. A survey questionnaire was administered to 307 respondents, after which focus group discussions were conducted to clarify responses regarding mosquito swarms and malaria transmission. Findings from both study components were used to draw qualitative inferences. Results Most community members (83%) had previously seen mosquito swarms, predominantly in farms, over long grasses or bushes, above ponds and over roofs of houses and pit-latrines. However, there was little evidence that community members could distinguish between mosquito swarms and those of other insects. Neither were they aware that swarms consisted mostly of male mosquitoes. Swarming was associated with mosquitoes preparing to attack people, foraging for food, playing or resting. Very few respondents associated swarming with mosquito mating. Nearly all community members were willing to accept interventions targeting mosquito swarms; and approximately three quarters would pay for such interventions, between 0.9 and 2.3 USD/year. Conclusion Majority of the community members recognized presence of mosquito swarms in their communities but did not associate these swarms with mosquito mating. Instead, swarming was associated with mosquitoes seeking food or planning to attack people, and thus were generally considered dangerous. This understanding created the basis for wide-acceptance of interventions targeting swarming mosquitoes. Although the likelihood of actual interventions targeting swarms is still low, such community knowledge will be crucial in future field studies of mosquito swarms and possible inclusion of community members in mosquito control efforts.…

Abstract Background Severe malaria in children is often associated with long-term behavioural and cognitive problems. A sizeable minority of children go on to experience repeated malaria due to the high transmission and infection rates in the region. The purpose of this study was to explore caregivers’ experiences of parenting a child with a history of severe malaria followed by repeated episodes of uncomplicated malaria in comparison to healthy community children. Methods Thirty-one caregivers were enrolled in the study. These included caregivers of children previously exposed to severe malaria and who had experienced repeated uncomplicated malaria attacks (SM with RMA, n = 15), caregivers of children exposed to severe malaria who did not experience repeated episodes (SM, n = 10), and caregivers of healthy community children (CC, n = 6) were purposively selected. Results Thematic-content analysis generated eight areas of concern, six of which were noted only by caregivers of children with SM or SM with RMA: (1) a sense of helplessness; (2) challenges with changes in behaviour; (3) responses to a child’s behaviour; (4) family life disruptions, including breakdown of relationships and inadequate male-spouse involvement in child care; (5) disagreements in seeking healthcare; (6) societal burden; and two by caregivers of children with SM, SM with RMA and also CC; (7) concern about academic achievement; and, (8) balancing work and family life. Conclusions The study findings suggest that severe malaria, especially when followed by repeated malaria episodes, affects not only children who have the illness but also their caregivers. The effects on caregivers can decrease their social functioning and isolate them from other parents and may disrupt families. Interventions to support caregivers by counselling the ongoing problems that might be expected in children who have had severe malaria and repeated episodes of malaria, and how to manage these problems, may provide a way to improve behavioural and mental health outcomes for those children and their caregivers.…

Abstract Background Haiti and the Dominican Republic, the only two Caribbean countries with endemic malaria transmission, are committed to eliminating malaria. With a Plasmodium falciparum prevalence under 1% and a highly focal transmission, the efforts towards elimination in Haiti will include several community-based interventions that must be tailored to the local sociocultural context to increase their uptake. However, little is known about local community perceptions regarding malaria and the planned elimination interventions. The aim of this study is to develop a robust understanding of how to tailor, implement and promote malaria elimination strategies in Haiti. Methods A cross-sectional qualitative study was conducted December 2015–August 2016 in Grande-Anse and the North Department in Haiti. Data collection included key informant interviews (n = 51), in-depth interviews (n = 15) and focus group discussions (n = 14) with health workers, traditional healers, teachers, priests or pastors, informal community leaders, public officials, and community members. Following a grounded theory approach, transcripts were coded and analysed using content analysis. Coded text was sorted by the types of interventions under consideration by the malaria elimination programme. Results The level of knowledge about malaria was low. Many participants noted community beliefs about malaria being caused by magical phenomena in addition to vector-borne transmission. Participants described malaria as a problem rooted in the environment, with vector control the most noted method of prevention. Though participants noted malaria a severe disease, it ranked lower than other health problems perceived as more acute. Access barriers to healthcare were described including a lack of bed nets. Some distrust about pills, tests, and foreigners in general was expressed, and in few cases linked to previous experience with malaria campaigns under dictatorial regimes. Conclusions There are several potential barriers and opportunities to implement community-based malaria elimination interventions in rural Haiti. Elimination efforts should include the collaboration of voodoo priests and other traditional healers, be coupled with solutions to wider community concerns or other health interventions, and learn from previous or similar programmes, such as the campaign to eliminate lymphatic filariasis. It is essential to engage with communities and gain their trust to successfully implement targeted aggressive elimination activities.…

Schlagenhauf P, Patel D.

Anna Maria van Eijk, David A Larsen, Kassoum Kayentao, Gibby Koshy, Douglas E C Slaughter, Cally Roper, Lucy C Okell, Meghna Desai, Julie Gutman, Carole Khairallah, Stephen J Rogerson, Carol Hopkins Sibley, Steven R Meshnick, Steve M Taylor, Feiko O ter Kuile

The effectiveness of sulfadoxine-pyrimethamine IPTp is reduced in areas with high resistance to sulfadoxine-pyrimethamine among P falciparum parasites, but remains associated with reductions in low birthweight even in areas where dhps Lys540Glu prevalence exceeds 90% but where the sextuple-mutant parasite (harbouring the additional dhps Ala581Gly mutation) is uncommon. Therapeutic alternatives to sulfadoxine-pyrimethamine IPTp are needed in areas where the prevalence of the sextuple-mutant parasite exceeds 37%.

Annie Haakenstad, Anton Connor Harle, Golsum Tsakalos, Angela E Micah, Tianchan Tao, Mina Anjomshoa, Jessica Cohen, Nancy Fullman, Simon I Hay, Tomislav Mestrovic, Shafiu Mohammed, Seyyed Meysam Mousavi, Molly R Nixon, David Pigott, Khanh Tran, Christopher J L Murray, Joseph L Dieleman

Tracking global malaria spending provides insight into how far the world is from reaching the malaria funding target of $6·6 billion annually by 2020. Because most countries with a high burden of malaria are low income or lower-middle income, mobilising additional government resources for malaria might be challenging.

Joey Brooke, Devi Sridhar

In The Lancet Infectious Diseases, Joseph Dieleman and colleagues describe how global malaria spending has changed between 2000 and 2016, using data from 106 malaria-endemic countries. They analyse the proportions of government spending, out-of-pocket spending, and prepaid private contributions to total malaria spending, including the costs for treatment seeking, care, and drugs. Although total annual malaria spending has increased in this period to US$4·3 billion, they conclude that we are still off meeting target annual funding by 2020 by $2·3 billion.

Richard Barnett

From 1817 onwards European governments, struggling in the aftermath of the Napoleonic Wars, watched with growing horror as a new and terrible disease left its historical heartland in south Asia and began to move west. Cholera, in the words of an editorial in the Quarterly Review, was “one of the most terrible pestilences which have ever devastated the earth”. Like malaria or HIV/AIDS, cholera has an inescapably global history: seven subsequent pandemics have provoked revolutions in public health, and an entirely new vision of global medicine in an age of interconnection.

Rocco Friebel, Rachel Silverman, Amanda Glassman, Kalipso Chalkidou

Since its inception in 2002, the Global Fund to Fight AIDS, Tuberculosis and Malaria (the Global Fund) has disbursed more than US$39 billion across 120 countries. Funding provided by donors, mainly the USA, France, the UK, Germany, and Japan, has undoubtedly affected the lives of millions of people. As the Global Fund approaches its Sixth Replenishment Conference—to be held in France in October, 2019—the recently published results report1 appears to make a compelling case for further investment.

Hubert Bassene, El Hadji Amadou Niang, Florence Fenollar, Bachar Dipankar, Souleymane Doucouré, Essoham Ali, Caroline Michelle, Didier Raoult, Cheikh Sokhna and Oleg Mediannikov

Abstract. In the context of the pre-elimination of malaria, biological control may provide an alternative or additional tool to current malaria control strategies. During their various stages of development, mosquitoes undergo subsequent changes in their associated microbiota, depending on their environment and nutritional status. Although Anopheles gambiae s.l. and Anopheles funestus are the two major malaria vectors in Senegal, the composition of their microbiota is not yet well known. In this study, we explored the microbiota of mosquitoes naturally infected or not by Plasmodium falciparum (Pf) using the 16S ribosomal RNA gene-based bacterial metagenomic approach. In both vector species, the microbiota was more diverse in Pf-infected samples than in the noninfected ones, although the total number of reads appeared to be higher in noninfected mosquitoes. Overall, the microbiota was different between the two vector species. Noteworthy, the bacterial microbiota was significantly different between Pf-positive and Pf-negative groups whatever the species, but was similar between individuals of the same infection status within a species. Overall, the phylum of Proteobacteria was the most predominant in both species, with bacteria of the genus Burkholderia outweighing the others in noninfected vectors. The presence of some specific bacterial species such as Asaia bogorensis, Enterobacter cloacae, Burkholderia fungorum, and Burkholderia cepacia was also observed in Pf-free samples only. These preliminary observations pave the way for further characterization of the mosquito microbiota to select promising bacterial candidates for potential use in an innovative approach to controlling malaria and overcoming the challenges to achieving a malaria-free world.…

Abstract This opinion article deals with the diagnostic clinical challenges faced by clinicians or health care workers in malaria-endemic areas when a severely sick child presents to the clinic with fever, coma or respiratory distress. Indeed, the coexistence of malaria with other severe infections like meningitis, invasive bacterial infection or pneumonia makes appropriate treatment allocation a matter of life and death. The use of biomarkers has been proposed as a potential solution to this problem. The arrival of high-throughput technologies allowed thousands of molecules (transcripts, proteins and metabolites) to be been screened in clinical samples from large cohorts of well/characterised patients. The major aim of these studies was to identify biomarkers that inform important decisions: should this child be referred to hospital? Should antibiotics, anti-malarials, or both, be administered? There is a large discrepancy between the number of biomarker discovery studies published and the number of biomarkers that have been clinically validated, let alone implemented. This article reflects on the many opportunities and obstacles encountered in biomarker research in malaria-endemic areas.…

Abstract Background Plasmodium malariae is the most neglected of the six human malaria species and it is still unknown which is the mechanism underlying the long latency of this Plasmodium. Case presentation A case of PCR-confirmed P. malariae recurrence in a 52-year old Italian man was observed 5 months after a primary attack. In the interval between the two observed episodes of malaria the patient denied any further stay in endemic areas except for a visit to Libya, a country considered malaria-free. Genomic DNA of the P. malariae strain using five microsatellites (PM2, PM9, PM11, PM25, PM34) and the antigen marker of circumsporozoite (csp) was amplified and sequenced. Analysis of polymorphisms of the P. malariae csp central repeat region showed differences between the strains responsible of the first and second episode of malaria. A difference in the allele size was also observed for the sequence analysis of PM2 microsatellites. Conclusions Plasmodium malariae is a challenging human malaria parasite and even with the use of molecular techniques the pathogenesis of recurrent episodes cannot be precisely explained.…

Abstract Background Plasmodium ovale curtisi and Plasmodium ovale wallikeri are regarded as less virulent forms of malaria with a geographic distribution including Southeast Asia, Central and West Africa, and is increasingly reported as an infection in returning travellers. A species of malaria that may have delayed or relapsing presentations similar to Plasmodium vivax, the clinical presentation of P. ovale spp. has been described to have prepatent periods of 2 weeks or slightly longer with reports of relapse following primary infection out to 8–9 months. This presentation may be obscured further in the setting of anti-malarial exposure, with report of delayed primary infection out to 4 years. Presented is a cluster of 4 imported P. ovale spp. cases in returning Peruvian military personnel assigned to United Nations peace-keeping operations in the Central African Republic. Case presentation From January to December 2016, Peruvian peace-keepers were deployed in support of United Nations (UN) operations in the Central African Republic (CAR). While serving abroad, Navy, Army, and Air Force members experienced 223 episodes of Plasmodium falciparum malaria following interruption of prophylaxis with mefloquine. Diagnosis was made using rapid diagnostics tests (RDTs) and/or smear with no coinfections identified. Cases of malaria were treated with locally-procured artemether-lumefantrine. Returning to Peru in January 2017, 200 peace-keepers were screened via thick and thin smear while on weekly mefloquine prophylaxis with only 1 showing nucleic acid within red blood cells consistent with Plasmodium spp. and 11 reporting syndromes of ill-defined somatic complaints. Between a period of 5 days to 11 months post return, 4 cases of P. ovale spp. were diagnosed using smear and polymerase chain reaction (PCR) following febrile complaints. All cases were subsequently treated with chloroquine and primaquine, with cure of clinical disease and documented clearance of parasitaemia. Conclusion These patients represent the first imported cases in Peru of this species of malaria as well as highlight the challenges in implementing population level prophylaxis in a deployed environment, and the steps for timely diagnosis and management in a non-endemic region where risk of introduction for local transmission exists.…

Abstract Background Despite malaria control programmes having successfully increased the number of households owning insecticide-treated nets (ITNs) in Malawi, the population of people with ITN access but still not using them fluctuated from 13% in 2010, 5% in 2012 and then 12% in 2015. This study aimed to compare the rate and factors associated with ITN usage among children under 5 years of age, living in household with at least one ITN, in Malawi between 2010 and 2015. Methods The 2010 and 2015–2016 Malawi Demographic and Health Surveys (MDHSs) were utilized. Only children from households that owned at least one ITN were selected. Multivariate logistic regression analyses were performed to examine associations of child, maternal and household factors with ITN usage. Results In total, 12,378 and 10,196 children under 5 years of age were examined from 2010 and 2015–2016, respectively. ITN usage increased from 57.8% (95% Confidence interval (CI): 56.1%–59.4%) in 2010 to 69.0% (95% CI 67.4%–70.5%) in 2015. The multivariate analysis revealed that, among others, being aged ≥ 24 months, having mothers with no formal education or with primary education, residing in a female-headed household, and residing in households that had poor household ITN supply were significantly associated with reduced odds of ITN usage. Conclusions ITNs are a key vector control intervention in malaria prevention. This study revealed increased ITN usage among children under 5 years old in the 5-year period, suggesting that considerable improvements have been made. However, continued efforts to increase awareness of the importance of using ITNs in malaria prevention in Malawi are necessary. Findings from this research provide some policy implications, especially for improving household ITN supply, to improve ITN utilization in Malawi.…

Abstract Background Accurate diagnosis of malaria is important for effective disease management and control. In Cameroon, presumptive clinical diagnosis, thick-film microscopy (TFM), and rapid diagnostic tests (RDT) are commonly used to diagnose cases of Plasmodium falciparum malaria. However, these methods lack sensitivity to detect low parasitaemia. Polymerase chain reaction (PCR), on the other hand, enhances the detection of sub-microscopic parasitaemia making it a much-needed tool for epidemiological surveys, mass screening, and the assessment of interventions for malaria elimination. Therefore, this study sought to determine the frequency of cases missed by traditional methods that are detected by PCR. Methods Blood samples, collected from 551 febrile Cameroonian patients between February 2014 and February 2015, were tested for P. falciparum by microscopy, RDT and PCR. The hospital records of participants were reviewed to obtain data on the clinical diagnosis made by the health care worker. Results The prevalence of malaria by microscopy, RDT and PCR was 31%, 45%, and 54%, respectively. However, of the 92% of participants diagnosed as having clinical cases of malaria by the health care worker, 38% were malaria-negative by PCR. PCR detected 23% and 12% more malaria infections than microscopy and RDT, respectively. A total of 128 (23%) individuals had sub-microscopic infections in the study population. The sensitivity of microscopy, RDT, and clinical diagnosis was 57%, 78% and 100%; the specificity was 99%, 94%, and 17%; the positive predictive values were 99%, 94%, and 59%; the negative predictive values were 66%, 78%, and 100%, respectively. Thus, 41% of the participants clinically diagnosed as having malaria had fever caused by other pathogens. Conclusions Malaria diagnostic methods, such as TFM and RDT missed 12–23% of malaria cases detected by PCR. Therefore, traditional diagnostic approaches (TFM, RDT and clinical diagnosis) are not adequate when accurate epidemiological data are needed for monitoring malaria control and elimination interventions.…

Sally Peprah, Constance Tenge, Isaiah O. Genga, Mediatrix Mumia, Pamela A. Were, Robert T. Kuremu, Walter N. Wekesa, Peter O. Sumba, Tobias Kinyera, Isaac Otim, Ismail D. Legason, Joshua Biddle, Steven J. Reynolds, Ambrose O. Talisuna, Robert J. Biggar, Kishor Bhatia, James J. Goedert, Ruth M. Pfeiffer and Sam M. Mbulaiteye

Abstract. The burden of Plasmodium falciparum (Pf) malaria in Kenya is decreasing; however, it is still one of the top 10 causes of morbidity, particularly in regions of western Kenya. Between April 2015 and June 2016, we enrolled 965 apparently healthy children aged 0–15 years in former Nyanza and Western Provinces in Kenya to characterize the demographic, geographic, and household risk factors of asymptomatic malaria as part of an epidemiologic study to investigate the risk factors for endemic Burkitt lymphoma. The children were sampled using a stratified, multistage cluster sampling survey design. Malaria was assessed by rapid diagnostic test (RDT) and thick-film microscopy (TFM). Primary analyses of Pf malaria prevalence (pfPR) are based on RDT. Associations between weighted pfPR and potential risk factors were evaluated using logistic regression, accounting for the survey design. Plasmodium falciparum malaria prevalence was 36.0% (27.5%, 44.5%) by RDT and 22.3% (16.0%, 28.6%) by TFM. Plasmodium falciparum malaria prevalence was positively associated with living in the lake-endemic area (adjusted odds ratio [aOR] 3.46; 95% confidence interval [95% CI] 1.63, 7.37), paternal occupation as peasant farmer (aOR 1.87; 1.08, 3.26) or manual laborer (aOR 1.83; 1.00, 3.37), and keeping dogs (aOR 1.62; 0.98–2.69) or cows (aOR 1.52; 0.96–2.40) inside or near the household. Plasmodium falciparum malaria prevalence was inversely associated with indoor residual insecticide spraying (IRS) (aOR 0.44; 0.19, 1.01), having a household connected to electricity (aOR 0.47; 0.22, 0.98), and a household with two (aOR 0.45; 0.22, 0.93) or ≥ three rooms (aOR 0.41; 0.18, 0.93). We report high but geographically heterogeneous pfPR in children in western Kenya and significant associations with IRS and household-level socioeconomic factors.…

Abstract Background The roll out of antiretroviral therapy (ART) in Sub-Saharan Africa led to a decrease in mortality. Few studies have documented the causes of deaths among patients on long term antiretroviral therapy in Sub-Saharan Africa. Our objective was to describe the causes of death among patients on long term ART in Sub-Saharan Africa. Methods We used data from a prospective cohort of ART naïve patients receiving care and treatment at the Infectious Diseases Institute in Kampala, Uganda. Patients were followed up for 10 years. All deaths were recorded and possible causes established using verbal autopsy. Deaths were grouped as HIV-related (ART toxicities, any opportunistic infections (OIs) and HIV-related malignancies) and non-HIV related deaths while some remained unknown. We used Kaplan Meier survival methods to estimate cumulative incidence and rates of mortality for all causes of death. Results Of the 559, (386, 69%) were female, median age 36 years (IQR: 21–44), 89% had WHO clinical stages 3 and 4, and median CD4 count at ART initiation was 98 cells/μL (IQR: 21–163). A total of 127 (22.7%) deaths occurred in 10 years. The HIV related causes of death (n = 70) included the following; Tuberculosis 17 (24.3%), Cryptococcal meningitis 10 (15.7%), Kaposi’s Sarcoma 7(10%), HIV related toxicity 6 (8.6%), HIV related anemia 5(7.1%), Pneumocystis carinii Pneumonia (PCP) 5 (7.1%), HIV related chronic diarrhea 4 (5.7%), Non-Hodgkin Lymphoma 3 (4.3%), Herpes Zoster 2 (2.8%), other 10 (14.3%). The non-HIV related causes of death (n = 20) included non-communicable diseases (diabetes, hypertension, stroke) 6 (30%), malaria 3 (15%), pregnancy-related death 2 (10%), cervical cancer 2 (10%), trauma 1(5%) and others 6 (30%). Conclusion Despite the higher rates of deaths from OIs in the early years of ART initiation, we observed an emergence of non-HIV related causes of morbidity and mortality. It is recommended that HIV programs in resource-limited settings start planning for screening and treatment of non-communicable diseases.…

Abstract Background Despite the development of resistance to Plasmodium falciparum malaria, sulfadoxine–pyrimethamine is still effective for intermittent preventive treatment of malaria in pregnancy (IPTp). In Tanzania, more than 10 years have passed since sulfadoxine–pyrimethamine and sulfamethopyrazine–pyrimethamine (SPs) were reserved for IPTp only. However, the retail pharmaceutical outlet dispensers’ knowledge and their compliance with the policies have not been recently explored. Therefore, this study was designed to investigate dispensers’ knowledge about these medications together with their actual dispensing practices, a decade since they were limited for IPTp use only. Methods This descriptive cross-sectional study was conducted between February and July 2017 in all municipalities of Dar-es-Salaam city. Data were collected by direct interviews using a structured questionnaire to assess knowledge and a simulated client approach was used to assess the actual practice of medicine dispensers. Data analysis was done by using SPSS version 20 and Chi square test was used to test significant differences in proportions between different categorical variables. A p-value of less than 0.05 was considered to be statistically significant. Results A random sample of 422 medicine dispensers participated in this study whereby 185 (43.8%) were from community pharmacies and 237 (56.2%) from accredited drug dispensing outlets. The study revealed that SPs were available in 76% of the community pharmaceutical outlets in Dar es Salaam. In general majority of the dispensers (64%) had moderate to high knowledge about SPs and their indication. About 80% of the dispensers were aware that SP is reserved for IPTp. However, irrespective of the level of knowledge, almost all dispensers (92%) were willing to dispense the medicines for the purpose of treating malaria, contrary to the current Tanzania malaria treatment guideline. Conclusion Majority of the medicine dispensers in the community pharmaceutical outlets were knowledgeable about SPs and their indications. Disappointingly, almost all dispensers irrespective of their levels of knowledge were willing to dispense SPs for treatment of malaria contrary to the available treatment guidelines.…

Abstract Reaching the overall goal of eliminating malaria requires halting disease transmission. One approach to blocking transmission is to prevent passage of the parasite to a mosquito, by preventing formation or transmission of gametocytes. An alternative approach, pioneered in the veterinary field, is to use endectocides, which are molecules that render vertebrate blood meals toxic for the mosquito vector, also killing the parasite. Field studies and modelling suggest that reducing the lifespan of the mosquito may significantly reduce transmission, given the lengthy maturation process of the parasite. To guide the development of new endectocides, or the reformulation of existing molecules, it is important to construct a framework of the required attributes, commonly called the target candidate profile. Here, using a combination of insights from current endectocides, mathematical models of the malaria transmission dynamics, and known impacts of vector control, a target candidate profile (TCP-6) and a regulatory strategy are proposed for a transmission reducing agent. The parameters chosen can be used to assess the potential of a new medicine, independent of whether it has classical endectocide activity, reduces the insect and parasite lifespan or any combination of all three, thereby constituting an ‘endectocidal transmission blocking’ paradigm.…

Abstract Background The transcriptional regulation that occurs in malaria parasites during the erythrocytic stages of infection can be studied in vivo with rodent malaria parasites propagated in mice. Time-series transcriptome profiling commonly involves the euthanasia of groups of mice at specific time points followed by the extraction of parasite RNA from whole blood samples. Current methodologies for parasite RNA extraction involve several steps and when multiple time points are profiled, these protocols are laborious, time-consuming, and require the euthanization of large cohorts of mice. Results A simplified protocol has been designed for parasite RNA extraction from blood volumes as low as 20 μL (microsamples), serially bled from mice via tail snips and directly lysed with TRIzol reagent. Gene expression data derived from microsampling using RNA-seq were closely matched to those derived from larger volumes of leucocyte-depleted and saponin-treated blood obtained from euthanized mice with high reproducibility between biological replicates. Transcriptome profiling of microsamples taken at different time points during the intra-erythrocytic developmental cycle of the rodent malaria parasite Plasmodium vinckei revealed the transcriptional cascade commonly observed in malaria parasites. Conclusions Microsampling is a quick, robust and cost-efficient approach to sample collection for in vivo time-series transcriptomic studies in rodent malaria parasites.…

Xiao Hong Li, Anatoly Kondrashin, Brian Greenwood, Kim Lindblade, Gawrie Loku Galappaththy, Pedro Alonso

A malaria-free world remains the vision of the global community. Malaria elimination within the territory of a country is a pathway to achieving the ultimate goal of eradication. Certification of malaria elimination in a country is the official recognition of this important achievement. The concepts of eradication and elimination, and criteria for certification of malaria elimination, have guided national programs in their efforts to achieve and maintain elimination. They have evolved from the experiences and setbacks of the global eradication program, and on the contemporaneous understanding of the concepts of achieving and maintaining elimination.

Abstract Background The transmission of malaria to mosquitoes depends on the presence of gametocytes that circulate in the peripheral blood of infected human hosts. Sensitive estimates of the densities of female gametocytes (FG) and male gametocytes (MG) may allow the prediction of infectivity to mosquitoes and thus a molecular estimate of the human infectious reservoir for transmission. Methods A novel multiplex qRT-PCR assay with intron-spanning primers was developed for the parallel quantification of FG and MG. CCp4 (PF3D7_0903800) transcripts specific for FG and PfMGET (PF3D7_1469900) transcripts specific for MG were quantified in total nucleic acids. The assay was validated on sex-sorted gametocytes from culture material and on samples from clinical trials with gametocytocidal drugs. Synthetic RNA standards were generated for the two targets genes and calibrated against known gametocyte quantities. Results The limit of detection was determined at 0.1 male and 0.1 female gametocyte/µL, which was equal to the limit of quantification (LOQ) for MG, while the LOQ for FG was 1 FG/µL. Results from previously reported clinical trials that used separate gametocyte qRT-PCR assays for FG (targeting Pfs25) and MG (targeting PfMGET) were reproduced with the multiplex assay. High levels of agreement between separate assays and the multiplex approach were observed (R2 = 0.9473, 95% CI 0.9314–0.9632, for FG measured by transcript levels of Pfs25 in qRT-PCR or CCp4 in multiplex; R2 = 0.8869, 95% CI 0.8541–0.9197, for MG measured by PfMGET in either single or multiplex qRT-PCR). FG and MG transcripts were detected in pure ring stage parasites at 10,000- and 100,000-fold reduced frequency for CCp4 and PfMGET, respectively. The CCp4 and PfMGET transcripts were equally stable under suboptimal storage conditions. Conclusions Gametocyte densities and their sex ratios can be determined in the presented one-step multiplex assay with higher throughput than single assays. The interpretation of low gametocyte densities at asexual parasite densities above 1000 parasites/µL requires caution to avoid false positive gametocyte signals from spurious transcript levels in ring stage parasites.…

Abstract Background The steady supply of quality, affordable medicines is a pillar of a functioning health system. In addition to the public sector, the private, mission and not-for-profit sectors often serve a large part of the population in Africa. However, while there is generally systematic recording of public sector supply of medicines, detailed, systematic and reliable national market data including these non-public sectors are not commonly available in most countries in Africa. Understanding the total market is a missing part of the access puzzle: without this information, policy makers and health practitioners are not able to fully measure the impact of interventions, measure access to effective products, or fully evaluate the rational use of medicines. This article reports on a unique innovation which provides routine, national-level data on the total pharmaceuticals market, through a system which can be replicated elsewhere. It demonstrates how national-level market data contribute to the evidence base for policies on access to essential medicines, using the Zambian anti-malarial medicines market as a case study. Methods A new, routine national database on pharmaceutical market size and structure was established through a multi-partner collaboration. Information was extracted from import authorizations and allows for information on local manufacture. Data included value and volume of products as well as pack details, manufacturer and importer. The system was continually updated: data for this analysis were extracted for 6 years: 2009–2014 inclusive. Data were analysed using Microsoft Excel and validated against other sources including donor procurement data. Analysis included public and private sector markets. The policy relevance was demonstrated through analysis of four aspects of national policies on access and rational use of malaria medicines: (i) volume of product relative to disease burden; (ii) distribution by sector relative to treatment-seeking; (iii) consistency of products with respect to national policy guidelines; (iv) market concentration as a proxy for security of supply. Results The system developed provides the first accurate, systematic data on the breakdown of a national pharmaceutical market in an African context. The total value of the anti-malarials market in Zambia, including all sectors, was USD 5.5–6 million. This included 22 different molecules or combinations, produced by 56 different manufacturers, with 142 different permutations of molecule/manufacturer/strength. Such data provide a complementary mechanism to confirm key trends in malaria treatment and control in Zambia: (i) sufficient supply relative to disease burden, (ii) value and volume of the private/non-profit sector; 29%–2% of market value and 17%–2% of market volume (from 2009 to 2014), (iii) dominance of the 3 molecules recommended in the national treatment guidelines; and (iv) an evidence-base for national discussions on medicines quality, security of supply and rationale use. The system extracts information on all medicines and therefore could be used to analyse other therapeutic classes. Data have been used for several policy purposes, notably by ZAMRA to monitor the quality of products in Zambia, monitoring implementation of WHO Resolutions on artemisinin monotherapy as well as monitoring trends in product choice across sectors. Conclusion Routine data are important for researchers and policy makers alike. This study shows how medicines data can be systematically gathered at national level—comprising range, volume and value in the public, private and not-for-profit sectors—to monitor more detailed trends in the market and allows triangulation of supply-side data against other sources. This systematic approach can contribute significantly to support access to medicines, monitor treatment and public health policies and create healthy markets. It can be used to monitor changes between therapeutic areas, for example the impact of improved malaria treatment on the use of antibiotics in the context of anti-microbial resistance monitoring. As data contain commercially confidential information, appropriate safeguards should be put in place to balance public health and commercial interests.…

Abstract Background The detection of submicroscopic infections in low prevalence settings has become an increasingly important challenge for malaria elimination strategies. The current field rapid diagnostic tests (RDTs) for Plasmodium falciparum malaria are inadequate to detect low-density infections. Therefore, there is a need to develop more sensitive field diagnostic tools. In parallel, a highly sensitive laboratory reference assay will be essential to evaluate new diagnostic tools. Recently, the highly sensitive Alere™ Malaria Ag P.f ELISA (HS ELISA) was developed to detect P. falciparum histidine-rich protein 2 (HRP2) in clinical whole blood specimens. In this study, the analytical and clinical performance of the HS ELISA was determined using recombinant P. falciparum HRP2, P. falciparum native culture parasites, and archived highly pedigreed clinical whole blood specimens from Karen village, Myanmar and Nagongera, Uganda. Results The HS ELISA has an analytical sensitivity of less than 25 pg/mL and shows strong specificity for P. falciparum HRP2 when tested against P. falciparum native culture strains with pfhrp2 and pfhrp3 gene deletions. Additionally, the Z′-factor statistic of 0.862 indicates the HS ELISA as an excellent, reproducible assay, and the coefficients of variation for inter- and intra-plate testing, 11.76% and 2.51%, were acceptable. Against clinical whole blood specimens with concordant microscopic and PCR results, the HS ELISA showed 100% (95% CI 96.4–100) diagnostic sensitivity and 97.9% (95% CI 94.8–99.4) diagnostic specificity. For P. falciparum positive specimens with HRP2 concentrations below 400 pg/mL, the sensitivity and specificity were 100% (95% CI 88.4–100) and 88.9% (95% CI 70.8–97.6), respectively. The overall sensitivity and specificity for all 352 samples were 100% (CI 95% 96–100%) and 97.3% (CI 95% 94–99%). Conclusions The HS ELISA is a robust and reproducible assay. The findings suggest that the HS ELISA may be a useful tool as an affordable reference assay for new ultra-sensitive HRP2-based RDTs.…

Sutherland C.

Sally Peprah, Herry Dhudha, Hillary Ally, Nestory Masalu, Esther Kawira, Colin N Chao, Isaiah O. Genga, Mediatrix Mumia, Pamela A. Were, Tobias Kinyera, Isaac Otim, Ismail D. Legason, Robert J. Biggar, Kishor Bhatia, James J. Goedert, Ruth M. Pfeiffer, Sam M. Mbulaiteye

Abstract Objectives Tanzania experiences significant malaria‐related morbidity and mortality, but accurate data are scarce. We update the data on patterns of low‐grade Plasmodium falciparum malaria infection among children in northern Tanzania. Methods P. falciparum malaria prevalence (pfPR) was assessed in a representative sample of 819 children enrolled in 94 villages in northern Tanzania between October 2015 and August 2016, using a complex survey design. Individual‐ and household‐level risk‐factors for pfPR were elicited using structured questionnaires. pfPR was assessed using rapid diagnostic tests (RDTs) and thick film microscopy (TFM). Associations with pfPR, based on RDT, were assessed using adjusted odds ratios (aOR) and confidence intervals (CI) from weighted survey logistic regression models. Results pfPR was 39.5% (95% CI: 31.5, 47.5) by RDT and 33.4% (26.0, 40.6) by TFM. pfPR by RDT was inversely associated with higher‐education parents, especially mothers (5‐7 years of education: aOR 0.55; 95% CI: 0.31, 0.96, senior secondary education: aOR 0.10; 95% CI: 0.02, 0.55), living in a house near the main road (aOR 0.34; 95% CI: 0.15, 0.76), in a larger household (2 rooms: aOR 0.40; 95% CI: 0.21, 0.79, more than 2 rooms OR 0.35; 95% CI: 0.20, 0.62). Keeping a dog near or inside the house was positively associated with pfPR (aOR 2.01; 95% CI: 1.26, 3.21). pfPR was not associated with bed‐net use or indoor residual spraying. Conclusions Nearly 40% of children in northern Tanzania had low‐grade malaria antigenemia. Higher parental education and household metrics but not mosquito bed‐net use, were inversely associated with pfPR. This article is protected by copyright. All rights reserved.

Erwan Atcheson, Karolis Bauza, Arturo Reyes-Sandoval

by Erwan Atcheson, Karolis Bauza, Arturo Reyes-Sandoval Malaria remains one the world’s most deadly infectious diseases, with almost half a million deaths and over 150 million clinical cases each year. An effective vaccine would contribute enormously to malaria control and will almost certainly be required for eventual eradication of the disease. However, the leading malaria vaccine candidate, RTS,S, shows only 30–50% efficacy under field conditions, making it less cost-effective than long-lasting insecticide treated bed nets. Other subunit malaria vaccine candidates, including TRAP-based vaccines, show no better protective efficacy. This has led to increased interest in combining subunit malaria vaccines as a means of enhancing protective efficacy. Mathematical models of the effect of combining such vaccines on protective efficacy can help inform optimal vaccine strategies and decision-making at all stages of the clinical process. So far, however, no such model has been developed for pre-clinical murine studies, the stage at which all candidate antigens and combinations begin evaluation. To address this gap, this paper develops a mathematical model of vaccine combination adapted to murine malaria studies. The model is based on simple probabilistic assumptions which put the model on a firmer theoretical footing than previous clinical models, which rather than deriving a relationship between immune responses and protective efficacy posit the relationship to be either exponential or Hill curves. Data from pre-clinical murine malaria studies are used to derive values for unknowns in the model which in turn allows simulations of vaccine combination efficacy and suggests optimal strategies to pursue. Finally, the ability of the model to shed light on fundamental biological variables of murine malaria such as the blood stage growth rate and sporozoite infectivity is explored.

Abstract Background Plasmodium vivax is the most geographically widespread of the human malaria parasites, causing 50,000 to 100,000 deaths annually. Plasmodium vivax parasites have the unique feature of forming dormant liver stages (hypnozoites) that can reactivate weeks or months after a parasite-infected mosquito bite, leading to new symptomatic blood stage infections. Efforts to eliminate P. vivax malaria likely will need to target the persistent hypnozoites in the liver. Therefore, research on P. vivax liver stages necessitates a marker for clearly distinguishing between actively replicating parasites and dormant hypnozoites. Hypnozoites possess a densely fluorescent prominence in the parasitophorous vacuole membrane (PVM) when stained with antibodies against the PVM-resident protein Upregulated in Infectious Sporozoites 4 (PvUIS4), resulting in a key feature recognizable for quantification of hypnozoites. Thus, PvUIS4 staining, in combination with the characteristic small size of the parasite, is currently the only hypnozoite-specific morphological marker available. Results Here, the generation and validation of a recombinant monoclonal antibody against PvUIS4 (α-rUIS4 mAb) is described. The variable heavy and light chain domains of an α-PvUIS4 hybridoma were cloned into murine IgG1 and IgK expression vectors. These expression plasmids were co-transfected into HEK293 cells and mature IgG was purified from culture supernatants. It is shown that the α-rUIS4 mAb binds to its target with high affinity. It reliably stains the schizont PVM and the hypnozoite-specific PVM prominence, enabling the visual differentiation of hypnozoites from replicating liver stages by immunofluorescence assays in different in vitro settings, as well as in liver sections from P. vivax infected liver-chimeric mice. The antibody functions reliably against all four parasite isolates tested and will be an important tool in the identification of the elusive hypnozoite. Conclusions The α-rUIS4 mAb is a versatile tool for distinguishing replicating P. vivax liver stages from dormant hypnozoites, making it a valuable resource that can be deployed throughout laboratories worldwide.…

Abstract Background Artemisinin-resistant Plasmodium falciparum has been reported throughout the Greater Mekong subregion and threatens to disrupt current malaria control efforts worldwide. Polymorphisms in kelch13 have been associated with clinical and in vitro resistance phenotypes; however, several studies suggest that the genetic determinants of resistance may involve multiple genes. Current proposed mechanisms of resistance conferred by polymorphisms in kelch13 hint at a connection to an autophagy-like pathway in P. falciparum. Results A SNP in autophagy-related gene 18 (atg18) was associated with long parasite clearance half-life in patients following artemisinin-based combination therapy. This gene encodes PfAtg18, which is shown to be similar to the mammalian/yeast homologue WIPI/Atg18 in terms of structure, binding abilities, and ability to form puncta in response to stress. To investigate the contribution of this polymorphism, the atg18 gene was edited using CRISPR/Cas9 to introduce a T38I mutation into a k13-edited Dd2 parasite. The presence of this SNP confers a fitness advantage by enabling parasites to grow faster in nutrient-limited settings. The mutant and parent parasites were screened against drug libraries of 6349 unique compounds. While the SNP did not modulate the parasite’s susceptibility to any of the anti-malarial compounds using a 72-h drug pulse, it did alter the parasite’s susceptibility to 227 other compounds. Conclusions These results suggest that the atg18 T38I polymorphism may provide additional resistance against artemisinin derivatives, but not partner drugs, even in the absence of kelch13 mutations, and may also be important in parasite survival during nutrient deprivation.…

Abstract Background There has been significant progress in eliminating malaria in Iran. The aim of this study is to investigate the structure of inter-organizational collaboration networks in the field of unauthorized immigrants and refugees access to services in order to eliminate malaria. Methods This study employed social network analysis, in which nodes represented stakeholders associated with providing access of immigrants and refugees to services in the field of malaria elimination, and ties indicated the level of collaboration. This study adopted socio-centric analysis and the whole network was studied. In this regard, 12 districts of the malaria-endemic area in Iran were selected. Participants included 360 individuals (30 representatives of the organization/group in each district). The data were gathered by interview, using the levels of collaboration scale. UCINET 6 was used for data analysis. The indices of density, centralization, reciprocity, and clustering were investigated for each twelve network and at each level of collaboration. Results The average density of the networks was 0.22 (SD: 0.04). In districts with a high incidence of imported malaria, the values of network density and centralization were high and the networks comprised of a larger connected component (less isolated clusters). There were significant correlations between density of network (r = 0.66, P = 0.02), degree centralization (r = 0.65, P = 0.02), betweenness centralization (r = 0.76, P = 0.004), and imported malaria cases. In general, the degree centrality and betweenness centrality of the organizations of health, district governor, and foreign immigrants’ affairs were higher. In all networks, 60% of the relationships were bilateral. At a higher level of collaboration, the centralization declined and reciprocity increased. The average of betweenness centralization index was 22.76 (SD = 3.88). Conclusions Higher values of network indices in border districts and districts with more cases of imported malaria, in terms of density and centralization measures, can propose the hypothesis that higher preparedness against the issue and centralization of power can enable a better top-down outbreak management, which needs further investigations. Higher centrality of governmental organizations indicates the need for involving private, non-governmental organizations and representatives of immigrant and refugee groups. Recognition of the existing network structure can help the authorities increase access to malaria prevention, diagnosis, and treatment services among immigrants and refugees.…

Abstract The Demographic and Health Surveys (DHS) Program has supported three household Malaria Indicator Surveys (MIS) in Madagascar. The results of 13 key malaria indicators from these surveys have been mapped as continuous surfaces using model-based geostatistical methods. The opportunities and limitations of these mapped outputs were discussed during a workshop in Antananarivo, Madagascar in July 2018, attended by 15 representatives from various implementation, policy and research stakeholder institutions in Madagascar. Participants evaluated the findings from the maps, using these to develop figures and narratives to support their work in the control of malaria in Madagascar.…

Juliana Inoue, Irina Jovel, Ulrika Morris, Berit Aydin-Schmidt, Atiqul Islam, Aluisio Cotrim Segurado, Anders Björkman, Silvia Di Santi and Andreas Mårtensson

Abstract. Artemisinin resistance, presently confined to Southeast Asia and associated with mutations in the Plasmodium falciparum K13 (PfK13) propeller domain, represents a serious threat to global malaria control. This study aimed to provide baseline information for future artemisinin resistance surveillance, by analyzing the PfK13 propeller domain in P. falciparum field isolates collected from the Brazilian Amazon Basin between 1984 and 2011. A total of 152 P. falciparum mono-infections were assessed, of which 118 (78%) were collected before and 34 (22%) after the introduction of artemisinin-based combination therapy (ACT) in 2006. An 849-base pair fragment encoding the PfK13 propeller was amplified by nested polymerase chain reaction and sequenced in both directions. The sequences were compared with the reference sequence of P. falciparum 3D7. All samples showed wild-type sequences, thus, no mutations were observed. The results are in agreement with other recent reports and do not provide evidence for presence of PfK13 propeller domain polymorphisms associated with artemisinin resistance among P. falciparum field isolates in the Brazilian Amazon Basin neither before nor after the implementation of ACT.…

Rachel D. Savage, Laura C. Rosella, Natasha S. Crowcroft, Maureen Horn, Kamran Khan, Monali Varia

by Rachel D. Savage, Laura C. Rosella, Natasha S. Crowcroft, Maureen Horn, Kamran Khan, Monali Varia An ongoing challenge of estimating the burden of infectious diseases known to disproportionately affect migrants (e.g. malaria, enteric fever) is that many health information systems, including reportable disease surveillance systems, do not systematically collect data on migrant status and related factors. We explored whether health administrative data linked to immigration records offered a viable alternative for accurately identifying cases of hepatitis A, malaria and enteric fever in Ontario, Canada. Using linked health care databases generated by Ontario’s universal health care program, we constructed a cohort of medically-attended individuals with presumed hepatitis A, malaria or enteric fever in Peel region using diagnostic codes. Immigrant status was ascertained using linked immigration data. The sensitivity and positive predictive value (PPV) of diagnostic codes was evaluated through probabilistic linkage of the cohort to Ontario’s reportable disease surveillance system (iPHIS) as the reference standard. Linkage was successful in 90.0% (289/321) of iPHIS cases. While sensitivity was high for hepatitis A and enteric fever (85.8% and 83.7%) and moderate for malaria (69.0%), PPV was poor for all diseases (0.3–41.3%). The accuracy of diagnostic codes did not vary by immigrant status. A dated coding system for outpatient physician claims and exclusion of new immigrants not yet eligible for health care were key challenges to using health administrative data to identify cases. Despite this, we show that linkages of health administrative and immigration records with reportable disease surveillance data are feasible and have the potential to bridge important gaps in estimating burden using either data source independently.  …

Abstract Background The Belgian Reference Laboratory for Plasmodium offers a free-of-charge reference testing of malaria-positive or doubtful samples to clinical laboratories. Methods The final malaria diagnosis from the Reference Laboratory (microscopy, rapid diagnostic tests (RDTs) and Plasmodium species-specific PCR) were compared with the final diagnosis from peripheral Belgian laboratories. The Reference Laboratory reports were analysed for all samples submitted between 2013 and 2017. Criteria assessed included the diagnosis of malaria, Plasmodium species identification including mixed infections, and in case of Plasmodium falciparum, the parasite density and the presence of sexual and asexual stages. Results A total of 947 non-duplicate samples were included. Reference testing confirmed 96.3% (893/927) and 90.0% (18/20) samples submitted as positive and negative, respectively, the two missed diagnoses were samples with Plasmodium ovale and Plasmodium malariae. Submitting laboratories had correctly identified P. falciparum in 95.1% (508/534) samples with P. falciparum single infection. They had correctly diagnosed the species in 62.9% (95/151) single non-falciparum samples and had reported ‘non-falciparum’ in another 26 (17.2%) samples; most errors occurred among P. malariae (n = 8/21, 38.1%) and P. ovale (n = 14/51, 27.5%). Only one of the 21 mixed Plasmodium species infections had been diagnosed as such by the submitting laboratories; in three of them, P. falciparum had been overlooked. Taken single and mixed infections together, P. falciparum was diagnosed in 98.6% (546/554) samples. Among 471 single P. falciparum samples available for comparison, laboratories had correctly reported parasite densities above 2% in 87.5% (70/80) samples; they had incorrectly reported parasite densities > 2% in an extra 52 (8.9%) samples. Laboratories had correctly reported P. falciparum schizonts and gametocytes in 25.6% (11/43) and 56.7% (17/30) samples, respectively. Conclusion Diagnostic laboratories in a malaria non-endemic setting provided excellent diagnosis of malaria and P. falciparum, reasonably good diagnosis of non-falciparum infections and acceptable calculation of P. falciparum parasite density.…

Abstract Background Plasmodium falciparum infected erythrocytes sequestering in placental tissue release Plasmodium lactate dehydrogenase (pLDH) and histidine-rich protein-II (HRP-II). These proteins can be detected in peripheral blood using monoclonal antibody-based rapid diagnostic tests (RDTs). Nevertheless, studies to evaluate the reliability of RDTs in detecting placental malaria compared with microscopy of placental tissue impression smear (PTIS) as the gold standard are scarce. Methods Between August 2013 and January 2015, Giemsa-stained blood smears for peripheral blood smear (Pbs), placental intervillous space (IVS) blood smear and placental tissue impression smear (PTIS)] were prepared from HIV-negative women during delivery at the Marie Reine Medical Health Centre in Yaoundé, Cameroon. RDTs with monoclonal antibodies specific to HRP-II (P.f) or pLDH (Pan) antigens were used to screen maternal peripheral blood samples. Results The prevalence of malaria was 16%, 7.5%, 11.5%, 8% and 13% for One Step malaria HRP-II and pLDH RDTs, peripheral blood smear, IVS blood and placental tissue impression smears, respectively. The proportion of women positive by One Step malaria pLDH RDT and Pbs increased with parasite density in PTIS, while One Step malaria HRP-II RDT detected high proportion of infected women even with low parasite density. Although the prevalence of malaria infection by both microscopy and RDTs decreased significantly with mother age (0.0008 ≤ p ≤ 0.025), parity seemed to have very little influence. The sensitivity of One Step malaria HRP-II and pLDH RDTs were 96.15% and 61.53%, respectively, compared to 80.76% for Pbs (p = 0.014 and 0.0029, respectively). The specificity of these RDTs was 96.49% and 100%, respectively, compared to 100% for Pbs (p ≥ 0.12). In addition, the positive predictive values were 80.64% and 100% for HRP-II and pLDH-based RDTs, respectively, compared to 100% for Pbs (p 

Rambhatla J, Turner L, Manning L, et al.

AbstractBackgroundPlasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) mediates parasite sequestration in postcapillary venules in P. falciparum malaria. PfEMP1 types can be classified based on their cysteine-rich interdomain region (CIDR) domains. Antibodies to different PfEMP1 types develop gradually after repeated infections as children age, and antibodies to specific CIDR types may confer protection.MethodsLevels of immunoglobulin G to 35 recombinant CIDR domains were measured by means of Luminex assay in acute-stage (baseline) and convalescent-stage plasma samples from Papua New Guinean children with severe or uncomplicated malaria and in healthy age-matched community controls.ResultsAt baseline, antibody levels were similar across the 3 groups. After infection, children with severe malaria had higher antibody levels than those with uncomplicated malaria against the endothelial protein C receptor (EPCR) binding CIDRα1 domains, and this difference was largely confined to older children. Antibodies to EPCR-binding domains increased from presentation to follow-up in severe malaria, but not in uncomplicated malaria.ConclusionsThe acquisition of antibodies against EPCR-binding CIDRα1 domains of PfEMP1 after a severe malaria episode suggest that EPCR-binding PfEMP1 may have a role in the pathogenesis of severe malaria in Papua New Guinea.

Abstract Background Malarial acute renal failure (MARF) is a component of the severe malaria syndrome, and complicates 1–5% of malaria infections. This form of renal failure has not been well characterized by histopathology. Case presentation A 44 year-old male presented to the emergency department with a 5-day history of fever and malaise after returning from Nigeria. A blood film was positive for Plasmodium falciparum. His creatinine was 616 µmol/L coming from a normal baseline of 89 µmol/L. He had a urine protein:creatinine ratio of 346 mg/mmol (4.4 g/L). He required dialysis. A renal biopsy showed acute interstitial nephritis with podocyte foot-process effacement. He was treated with artesunate and his renal function improved. At 1 year follow-up his creatinine had plateaued at 120 µmol/L with persistent low-grade proteinuria. Conclusion Acute interstitial nephritis and podocyte foot-process effacement might be under-recognized lesions in MARF. Studying the mechanisms of MARF could give insight into the immunopathology of severe malaria.…

Abstract Background Today, the development of new and well-tolerated anti-malarial drugs is strongly justified by the emergence of Plasmodium falciparum resistance. In 2014–2015, a phase 2b clinical study was conducted to evaluate the efficacy of a single oral dose of Artefenomel (OZ439)–piperaquine (PPQ) in Asian and African patients presenting with uncomplicated falciparum malaria. Methods Blood samples collected before treatment offered the opportunity to investigate the proportion of multidrug resistant parasite genotypes, including P. falciparum kelch13 mutations and copy number variation of both P. falciparum plasmepsin 2 (Pfpm2) and P. falciparum multidrug resistance 1 (Pfmdr1) genes. Results Validated kelch13 resistance mutations including C580Y, I543T, P553L and V568G were only detected in parasites from Vietnamese patients. In Africa, isolates with multiple copies of the Pfmdr1 gene were shown to be more frequent than previously reported (21.1%, range from 12.4% in Burkina Faso to 27.4% in Uganda). More strikingly, high proportions of isolates with multiple copies of the Pfpm2 gene, associated with piperaquine (PPQ) resistance, were frequently observed in the African sites, especially in Burkina Faso and Uganda (> 30%). Conclusions These findings were considered to sharply contrast with the recent description of increased sensitivity to PPQ of Ugandan parasite isolates. This emphasizes the necessity to investigate in vitro susceptibility profiles to PPQ of African isolates with multiple copies of the Pfpm2 gene and estimate the risk of development of PPQ resistance in Africa. Trial registration Clinicaltrials.gov reference: NCT02083380. Study title: Phase II efficacy study of artefenomel and piperaquine in adults and children with P. falciparum malaria. https://clinicaltrials.gov/ct2/results?cond=&term=NCT02083380&cntry=&state=&city=&dist=. FSFV: 23-Jul-2014; LSLV: 09-Oct-2015…

Abstract Background The degree to which insecticide-treated net (ITN) supply accounts for age and gender disparities in ITN use among household members is unknown. This study explores the role of household ITN supply in the variation in ITN use among household members in sub-Saharan Africa. Methods Data was from Malaria Indicator Surveys or Demographic and Health Surveys collected between 2011 and 2016 from 29 countries in sub-Saharan Africa. The main outcome was ITN use the previous night. Other key variables included ITN supply (nets/household members), age and gender of household members. Analytical methods included logistic regressions and meta-regression. Results Across countries, the median (range) of the percentage of households with enough ITNs was 30.7% (8.5–62.0%). Crude analysis showed a sinusoidal pattern in ITN use across age groups of household members, peaking at 0–4 years and again around 30–40 years and dipping among people between 5–14 and 50+ years. This sinusoidal pattern was more pronounced in households with not enough ITNs compared to those with enough ITNs. ITN use tended to be higher in females than males in households with not enough ITNs while use was comparable among females and males in households with enough ITNs. After adjusting for wealth quintile, residence and region, among households with not enough ITNs in all countries, the odds of ITN use were consistently higher among children under 5 years and non-pregnant women 15–49 years. Meta-regressions showed that across all countries, the mean adjusted odds ratio (aOR) of ITN use among children under 5 years, pregnant and non-pregnant women aged 15–49 years and people 50 years and above was significantly higher than among men aged 15–49 years. Among these household members, the relationship was attenuated when there were enough ITNs in the household (dropping 0.26–0.59 points) after adjusting for geographical zone, household ITN supply, population ITN access, and ITN use:access ratio. There was no significant difference in mean aOR of ITN use among school-aged children compared to men aged 15–49 years, regardless of household ITN supply. Conclusions This study demonstrated that having enough ITNs in the household increases level of use and decreases existing disparities between age and gender groups. ITN distribution via mass campaigns and continuous distribution channels should be enhanced as needed to ensure that households have enough ITNs for all members, including men and school-aged children.…

Abstract Background Plasmodium falciparum-infected erythrocytes (IE) sequester in deep vascular beds where their adhesion is mediated by an array of endothelial surface receptors. Because parasite adhesion has been associated with disease, antibodies that block this activity may confer protective immunity. Here, levels of plasma anti-adhesion activity and surface reactivity against freshly collected IEs from malaria-infected children were measured in a Malian birth cohort and related to child age and malaria infection history. Methods Plasma samples from children enrolled at birth in a longitudinal cohort study of mother–infant pairs in Ouelessebougou, Mali were collected at multiple time points during follow-up visits. Anti-adhesion antibodies (i.e., inhibit IE binding to any of several endothelial receptors) and reactivity with surface IE proteins were measured using a binding inhibition assay and by flow cytometry, respectively. Results Levels of antibodies that inhibit the binding of children’s IE to the receptors ICAM-1, integrin α3β1 and laminin increased with age. The breadth of antibodies that inhibit ICAM-1 and laminin adhesion (defined as the proportion of IE isolates whose binding was reduced by ≥ 50%) also significantly increased with age. The number of malaria infections prior to plasma collection was associated with levels of plasma reactivity to IE surface proteins, but not levels of anti-adhesion activity. Conclusions Age is associated with increased levels of antibodies that reduce adhesion of children’s IE to three of the ten endothelial receptors evaluated here. These results suggest that anti-adhesion antibodies to some but not all endothelial receptors are acquired during the first few years of life.…

Abstract Background Treatment of parasitic diseases has been challenging due to evolution of drug resistant parasites, and thus there is need to identify new class of drugs and drug targets. Protein translation is important for survival of malarial parasite, Plasmodium, and the pathway is present in all of its life cycle stages. Aminoacyl tRNA synthetases are primary enzymes in protein translation as they catalyse amino acid addition to the cognate tRNA. This study sought to understand differences between Plasmodium and human aminoacyl tRNA synthetases through bioinformatics analysis. Methods Plasmodium berghei, Plasmodium falciparum, Plasmodium fragile, Plasmodium knowlesi, Plasmodium malariae, Plasmodium ovale, Plasmodium vivax, Plasmodium yoelii and human aminoacyl tRNA synthetase sequences were retrieved from UniProt database and grouped into 20 families based on amino acid specificity. These families were further divided into two classes. Both families and classes were analysed. Motif discovery was carried out using the MEME software, sequence identity calculation was done using an in-house Python script, multiple sequence alignments were performed using PROMALS3D and TCOFFEE tools, and phylogenetic tree calculations were performed using MEGA vs 7.0 tool. Possible alternative binding sites were predicted using FTMap webserver and SiteMap tool. Results Motif discovery revealed Plasmodium-specific motifs while phylogenetic tree calculations showed that Plasmodium proteins have different evolutionary history to the human homologues. Human aaRSs sequences showed low sequence identity (below 40%) compared to Plasmodium sequences. Prediction of alternative binding sites revealed potential druggable sites in PfArgRS, PfMetRS and PfProRS at regions that are weakly conserved when compared to the human homologues. Multiple sequence analysis, motif discovery, pairwise sequence identity calculations and phylogenetic tree analysis showed significant differences between parasite and human aaRSs proteins despite functional and structural conservation. These differences may provide a basis for further exploration of Plasmodium aminoacyl tRNA synthetases as potential drug targets. Conclusion This study showed that, despite, functional and structural conservation, Plasmodium aaRSs have key differences from the human homologues. These differences in Plasmodium aaRSs can be targeted to develop anti-malarial drugs with less toxicity to the host.…

Abstract Background An estimated 30 million women give birth annually in malaria endemic areas of sub-Saharan Africa. Malaria in pregnancy is associated with an increased risk of adverse maternal and infant outcomes. To combat the adverse effects of MiP, the World Health Organization (WHO) recommends the provision of intermittent preventive treatment in pregnancy with sulfadoxine–pyrimethamine (IPTp–SP) in areas of moderate to high malaria transmission. In 2012, the WHO updated its policy with respect to IPTp administration to recommend administration at each antenatal care visit in the second and third trimesters, with a minimum of three, rather than two, doses. While rapid improvements in coverage were expected, gains have occurred more slowly than anticipated. Methods The President’s Malaria Initiative (PMI) assessed IPTp uptake before and after countries implemented the new WHO policy, and assessed how long it took for implementation to occur, using a combination of data from household surveys, routine health management information systems, and programmatic data provided to PMI. Results It took an average of 2 years for countries to complete the process of revising their IPTp policies, and it was not until 2015 that all 17 PMI countries had updated their policies. Policy dissemination and training had not been completed in several countries as of early 2018, and only seven countries had fully implemented the new policy including updating their antenatal care registers to collect information on IPTp3+ coverage. The coverage of IPTp1+, 2+, and 3+ has increased by 19, 16, and 13 percentage points since the revised IPTp policy adoption. Discussion Overall, coverage of both IPTp2+ and IPTp3+ has improved in recent years. The change in policy from a minimum of two to a minimum of three doses has likely contributed to these improvements. Progress has been slow, likely related to the complicated process of policy adoption exacerbated by the lag in measurement through national household surveys. The impact of future policy changes may be more readily seen if the policy change and implementation process were more streamlined and coordinated between key stakeholders (National Malaria Control Programmes and Reproductive Health Programmes), with more real-time data reporting.…

Natalie I Mazur, Louis J Bont, Johannes J M van Delden, Saad B Omer

Respiratory syncytial virus (RSV) is the second most frequent cause of death after malaria in the post-neonatal period,1 yet there is no vaccine or treatment besides supportive care.2 Prevention of RSV will be an important step in achieving Sustainable Development Goal target 3.2: to end preventable deaths of newborns and children younger than 5 years of age. Maternal vaccination is a powerful tool to prevent infection in the first months of life; neonatal tetanus mortality has been successfully reduced by 92% through maternal tetanus toxoid vaccination.

Woodford J, Collins K, Odedra A, et al.

AbstractBackgroundPlasmodium malariae is considered a ‘minor’ malaria parasite, although its global disease burden is underappreciated. The aim of this study was to develop an induced blood stage malaria (IBSM) model of P. malariae to study parasite biology, diagnostics, and treatment.MethodsThis clinical trial involved two healthy subjects who were intravenously inoculated with cryopreserved P. malariae-infected erythrocytes. Subjects were treated with artemether-lumefantrine following development of clinical symptoms. Prior to antimalarial therapy, mosquito feeding assays were performed to investigate transmission, and blood samples were collected for rapid diagnostic testing and parasite transcription profiling. Serial blood samples were collected for biomarker analysis.ResultsBoth subjects experienced symptoms and signs typical of early malaria. Parasitaemia was detected 7 days post-inoculation and increased until antimalarial treatment was initiated 25 and 21 days post-inoculation for Subject 1 and 2 respectively (peak parasitaemia levels were 174,182 and 50,291 parasites/mL respectively). The parasite clearance half-life following artemether-lumefantrine treatment was 6.7 hours. Mosquito transmission was observed for one subject, while in vivo parasite transcription and biomarkers were successfully profiled.ConclusionsAn IBSM model of P. malariae has been successfully developed and may be used to study the biology, diagnostics, and treatment of this neglected malaria species.

Abstract Background Prior to this project, only a handful of online visualizations existed for exploring the published literature on molecular markers of antimalarial drug resistance, and none specifically for the markers associated with Plasmodium falciparum resistance to the partner drugs in artemisinin-based combination therapy (ACT). Molecular information is collected in studies with different designs, using a variety of molecular methodologies and data analysis strategies, making it difficult to compare across studies. The purpose of this project was to develop a free online tool, which visualizes the widely published data on molecular markers of antimalarial drug resistance, starting with the two genes pfcrt and pfmdr-1, associated with resistance to the three most common partner drugs; amodiaquine, lumefantrine and mefloquine. Methods A literature review was conducted, and a standardized method was used to extract data from publications, and critical decisions on visualization were made. A global geospatial database was developed of specific pfmdr1 and pfcrt single nucleotide polymorphisms and pfmdr1 copy number variation. An informatics framework was developed that allowed flexibility in development of the tool over time and efficient adaptation to different source data. Results The database discussed in this paper has pfmdr1 and pfcrt marker prevalence information, from 579 geographic sites in 76 different countries, including results from over 86,000 samples from 456 articles published January 2001–May 2017. The ACT Partner Drugs Molecular Surveyor was launched by the WorldWide Antimalarial Resistance Network (WWARN) in March 2015 and it has attracted over 3000 unique visitors since then. Presented here is a demonstration of how the Surveyor database can be explored to monitor local, temporal changes in the prevalence of molecular markers. Here publications up to May 2017 were included, however the online ACT partner drug Molecular Surveyor is continuously updated with new data and relevant markers. Conclusions The WWARN ACT Partner Drugs Molecular Surveyor summarizes data on resistance markers in the pfmdr1 and pfcrt genes. The database is fully accessible, providing users with a rich resource to explore and analyze, and thus utilize a centralized, standardized database for different purposes. This open-source software framework can be adapted to other data, as demonstrated by the subsequent launch of the Artemisinin Molecular Surveyor and the Vivax Surveyor.…

Abstract Background Malaria transmission-blocking anti-malarial drugs, such as primaquine, offers an effective strategy for reducing the incidence of falciparum malaria. However, this drug induces haemolytic anaemia among glucose-6-phosphate dehydrogenase (G6PD) deficient individuals. The distribution of G6PD deficiency in Brazzaville, Republic of Congo and the association of G6PD deficiency with haemoglobin levels and blood cell counts were investigated. Methods A total of 212 febrile children were recruited for this study. Plasmodium falciparum diagnosis was conducted by microscopy and nested PCR. Sanger sequencing was used to assess G6PD deficiency by detecting 202G>A (rs1050828) and 376A>G (rs1050829) single nucleotide polymorphisms. Results Two hundred and twelve children were successfully genotyped for G6PD variants. Overall, 13% (27/212) of the children were G6PD deficient and 25% (25/100) females were heterozygous (11 BA− and 14 A+A−). The remaining 160 children had a normal G6PD genotype. The mean red blood and mean platelet counts were significantly lower in hemizygous male (G6PD A−) participants than in normal male (G6PD A+ or B) participants (p 

Abstract Malaria is a major cause of anaemia in tropical areas. Malaria infection causes haemolysis of infected and uninfected erythrocytes and bone marrow dyserythropoiesis which compromises rapid recovery from anaemia. In areas of high malaria transmission malaria nearly all infants and young children, and many older children and adults have a reduced haemoglobin concentration as a result. In these areas severe life-threatening malarial anaemia requiring blood transfusion in young children is a major cause of hospital admission, particularly during the rainy season months when malaria transmission is highest. In severe malaria, the mortality rises steeply below an admission haemoglobin of 3 g/dL, but it also increases with higher haemoglobin concentrations approaching the normal range. In the management of severe malaria transfusion thresholds remain uncertain. Prevention of malaria by vector control, deployment of insecticide-treated bed nets, prompt and accurate diagnosis of illness and appropriate use of effective anti-malarial drugs substantially reduces the burden of anaemia in tropical countries.…

Abstract Background Malaria is a major mosquito transmitted, blood-borne parasitic disease that afflicts humans. The disease causes anaemia and other clinical complications, which can lead to death. Plasmodium vivax is known for its reticulocyte host cell specificity, but many gaps in disease details remain. Much less is known about the closely related species, Plasmodium cynomolgi, although it is naturally acquired and causes zoonotic malaria. Here, a computational model is developed based on longitudinal analyses of P. cynomolgi infections in nonhuman primates to investigate the erythrocyte dynamics that is pertinent to understanding both P. cynomolgi and P. vivax malaria in humans. Methods A cohort of five P. cynomolgi infected Rhesus macaques (Macaca mulatta) is studied, with individuals exhibiting a plethora of clinical outcomes, including varying levels of anaemia. A discrete recursive model with age structure is developed to replicate the dynamics of P. cynomolgi blood-stage infections. The model allows for parasitic reticulocyte preference and assumes an age preference among the mature RBCs. RBC senescence is modelled using a hazard function, according to which RBCs have a mean lifespan of 98 ± 21 days. Results Based on in vivo data from three cohorts of macaques, the computational model is used to characterize the reticulocyte lifespan in circulation as 24 ± 5 h (n = 15) and the rate of RBC production as 2727 ± 209 cells/h/µL (n = 15). Analysis of the host responses reveals a pre-patency increase in the number of reticulocytes. It also allows the quantification of RBC removal through the bystander effect. Conclusions The evident pre-patency increase in reticulocytes is due to a shift towards the release of younger reticulocytes, which could result from a parasite-induced factor meant to increase reticulocyte availability and satisfy the parasite’s tropism, which has an average value of 32:1 in this cohort. The number of RBCs lost due to the bystander effect relative to infection-induced RBC losses is 62% for P. cynomolgi infections, which is substantially lower than the value of 95% previously determined for another simian species, Plasmodium coatneyi.…