Millat-Martinez, P., Ila, R., Laman, M., Robinson, L., Karunajeewa, H., Abel, H., Pulai, K., Sanz, S., Manning, L., Moore, B., Bassat, Q., Mitja, O.

Background: Mass drug administration (MDA) of sequential rounds of antimalarial drugs is being considered as a tool for malaria elimination. As an effective and long-acting antimalarial, Dihydroartemisinin-piperaquine (DHA/PQP) appears suitable as a candidate for MDA. However, absence of cardiac safety data following repeated administration hinders its use in the extended schedules proposed for MDA.Methods: We conducted an interventional study in Lihir Island, Papua New Guinea, with healthy individuals aged 3 to 60 years who received a standard 3-day course of DHA/PQP on 3 consecutive months. Twelve-lead electrocardiography (ECG) readings were conducted pre-dose and 4h after the final dose of each month. The primary safety endpoint was QTc (using Fridericia’s correction; QTcF) prolongation from baseline to 4h post-dosing. We compared the difference in prolongation between the third course post-dose and the first course post-dose.Results: Of 84 enrolled participants, 69 (82%) completed all treatment courses and ECG measurements. The average increase in QTcF was 19.6 ms (SD 17.8) and 17.1 ms (SD 17.1) for the first-course and third-course post-dosing ECGs [risk difference -2.4 (95%CI - 6.9 to 2.1), p=0.285], respectively. We recorded QTcF prolongation >60 ms from baseline in 3 (4.3%) and 2 (2.9%) participants after the first course and third course (p=1.00), respectively. No participants had QTcF intervals >500 ms at any time point.Conclusions: Three consecutive monthly courses of DHA/PQP were as safe as a single course. The absence of cumulative cardiotoxicity with repeated dosing support the use of monthly DHA/PQP as part of malaria elimination strategies.

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.

Alejandro Llanos-Cuentas, Martin Casapia, Raúl Chuquiyauri, Juan-Carlos Hinojosa, Nicola Kerr, Maria Rosario, Stephen Toovey, Robert H Arch, Margaret A Phillips, Felix D Rozenberg, Jade Bath, Caroline L Ng, Annie N Cowell, Elizabeth A Winzeler, David A Fidock, Mark Baker, Jörg J Möhrle, Rob Hooft van Huijsduijnen, Nathalie Gobeau, Nada Araeipour, Nicole Andenmatten, Thomas Rückle, Stephan Duparc

After a single dose of DSM265, P falciparum parasitaemia was rapidly cleared, whereas against P vivax, DSM265 showed less effective clearance kinetics. Its long duration of action provides the potential to prevent recurrence of P falciparum after treatment with a single dose, which should be further assessed in future combination studies.

Natalie E Hofmann, Maria Gruenberg, Elma Nate, Alice Ura, Daniela Rodriguez-Rodriguez, Mary Salib, Ivo Mueller, Thomas A Smith, Moses Laman, Leanne J Robinson, Ingrid Felger

Almost all potentially transmitting parasite carriers were identified with us-qPCR on fingerprick blood volumes. Analysing larger blood volumes revealed a large pool of ultra-low-density P falciparum and P vivax infections, which are unlikely to be transmitted. Therefore, current RDTs cannot replace molecular diagnostics for identifying potential P falciparum transmitters.

Titus H Divala, Randy G Mungwira, Patricia M Mawindo, Osward M Nyirenda, Maxwell Kanjala, Masiye Ndaferankhande, Lufina E Tsirizani, Rhoda Masonga, Francis Muwalo, Gail E Potter, Jessie Kennedy, Jaya Goswami, Blair J Wylie, Atis Muehlenbachs, Lughano Ndovie, Priscilla Mvula, Yamikani Mbilizi, Tamiwe Tomoka, Miriam K Laufer

Chloroquine administered as intermittent therapy did not provide better protection from malaria and related adverse effects compared with intermittent sulfadoxine-pyrimethamine in a setting of high resistance to sulfadoxine-pyrimethamine. Chloroquine chemoprophylaxis might provide benefit in protecting against malaria during pregnancy, but studies with larger sample sizes are needed to confirm these results.

Jordi Landier, Daniel M Parker, Aung Myint Thu, Khin Maung Lwin, Gilles Delmas, François H Nosten, Malaria Elimination Task Force Group

Providing early diagnosis and effective treatment substantially decreased village-level incidence of artemisinin-resistant P falciparum malaria in hard-to-reach, politically sensitive regions of eastern Myanmar. Targeted mass drug administration significantly reduced malaria incidence in hotspots. If these activities could proceed in all contiguous endemic areas in addition to standard control programmes already implemented, there is a possibility of subnational elimination of P falciparum.

Natacha Protopopoff, Jacklin F Mosha, Eliud Lukole, Jacques D Charlwood, Alexandra Wright, Charles D Mwalimu, Alphaxard Manjurano, Franklin W Mosha, William Kisinza, Immo Kleinschmidt, Mark Rowland

The PBO long-lasting insecticidal net and non-pyrethroid indoor residual spraying interventions showed improved control of malaria transmission compared with standard long-lasting insecticidal nets where pyrethroid resistance is prevalent and either intervention could be deployed to good effect. As a result, WHO has since recommended to increase coverage of PBO long-lasting insecticidal nets. Combining indoor residual spraying with pirimiphos-methyl and PBO long-lasting insecticidal nets provided no additional benefit compared with PBO long-lasting insecticidal nets alone or standard long-lasting insecticidal nets plus indoor residual spraying.

Immo Kleinschmidt, John Bradley, Tessa Bellamy Knox, Abraham Peter Mnzava, Hmooda Toto Kafy, Charles Mbogo, Bashir Adam Ismail, Jude D Bigoga, Alioun Adechoubou, Kamaraju Raghavendra, Jackie Cook, Elfatih M Malik, Zinga José Nkuni, Michael Macdonald, Nabie Bayoh, Eric Ochomo, Etienne Fondjo, Herman Parfait Awono-Ambene, Josiane Etang, Martin Akogbeto, Rajendra M Bhatt, Mehul Kumar Chourasia, Dipak K Swain, Teresa Kinyari, Krishanthi Subramaniam, Achille Massougbodji, Mariam Okê-Sopoh, Aurore Ogouyemi-Hounto

Irrespective of resistance, populations in malaria endemic areas should continue to use long-lasting insecticidal nets to reduce their risk of infection. As nets provide only partial protection, the development of additional vector control tools should be prioritised to reduce the unacceptably high malaria burden.

Roberto Amato, Richard D Pearson, Jacob Almagro-Garcia, Chanaki Amaratunga, Pharath Lim, Seila Suon, Sokunthea Sreng, Eleanor Drury, Jim Stalker, Olivo Miotto, Rick M Fairhurst, Dominic P Kwiatkowski

The KEL1/PLA1 co-lineage emerged in the same year that dihydroartemisinin–piperaquine became the first-line antimalarial drug in western Cambodia and spread rapidly thereafter, displacing other artemisinin-resistant parasite lineages. These findings have important implications for management of the global health risk associated with the current outbreak of multidrug-resistant malaria in southeast Asia.

The West African Network for Clinical Trials of Antimalarial Drugs (WANECAM)

Pyronaridine–artesunate and dihydroartemisinin–piperaquine treatment and retreatment of malaria were well tolerated with efficacy that was non-inferior to first-line ACTs. Greater access to these efficacious treatments in west Africa is justified.

Xin Hui S Chan, Yan Naung Win, Laura J Mawer, Jireh Y Tan, Josep Brugada, Nicholas J White

Dihydroartemisinin–piperaquine was associated with a low risk of sudden unexplained death that was not higher than the baseline rate of sudden cardiac death. Concerns about repolarisation-related cardiotoxicity need not limit its current use for the prevention and treatment of malaria.

Thuy-Nhien Nguyen, Lorenz von Seidlein, Tuong-Vy Nguyen, Phuc-Nhi Truong, Son Do Hung, Huong-Thu Pham, Tam-Uyen Nguyen, Thanh Dong Le, Van Hue Dao, Mavuto Mukaka, Nicholas PJ Day, Nicholas J White, Arjen M Dondorp, Guy E Thwaites, Tran Tinh Hien

Persistent largely asymptomatic P vivax and P falciparum infections are common in this area of low seasonal malaria transmission. Infections with low-density parasitaemias can develop into much higher density infections at a later time, which are likely to sustain malaria endemicity.

Anders B Björkman

Malaria parasitaemias are usually suppressed or eliminated in the human host by the immune system and antimalarial drugs. Low-density asymptomatic infections are therefore expected to be common in high-endemic areas with high herd immunity and premunition in the population. However, it is becoming increasingly apparent, with sensitive molecular PCR-based diagnostics, that submicroscopical asymptomatic infections are also common in low-endemic areas,1 despite residents having little protective or suppressive immunity.

Ric N Price, Nicholas J White

Substantial gains have been made in reducing the global burden of malaria, much of which can be attributed to greater access to prompt diagnosis and highly effective treatment. However, as endemic countries commit to eliminating malaria, more aggressive interventions are needed to target the large number of apparently healthy individuals who harbour transmissible malaria parasites. Although most national antimalarial guidelines recommend artemisinin combination therapy for the management of uncomplicated falciparum malaria, chemopreventive strategies have generally adopted non-artemisinin combination therapy regimens such as sulfadoxine-pyrimethamine and amodiaquine.

Didier Ménard, Jérôme Clain, Frédéric Ariey

Over the past decade, the burden of malaria has been greatly reduced in the Greater Mekong subregion, although artemisinin-resistant parasites have emerged,1,2 and high rates of treatment failure on dihydroartemisinin–piperaquine have been reported in Cambodia since 2012.3–7 Unsurprisingly, this situation is linked to the aggressive strategies implemented in this region to eliminate malaria and the inevitable massive reduction in the Plasmodium falciparum parasite population, leading to selection of best-adapted, multidrug-resistant parasites.

Onisillos Sekkides

In 2007 The Lancet Infectious Diseases published a special issue focussing on malaria in pregnancy. This highlighted that slow progress on prevention was being made at the time and that there were many research gaps needing to be addressed. A decade later we update readers with a new Series of three reports covering the burden, pathology, costs, prevention, and treatment of uncomplicated and severe malaria during pregnancy.

The Lancet

Last week, WHO released its first Essential Diagnostics List. Designed to complement the Essential Medicines list first released over 40 years ago, the list defines an essential package of diagnostic tests for use in primary care and laboratory settings. 58 of these tests are aimed at supporting the diagnosis and monitoring of common conditions such as cardiovascular diseases, diabetes, and anaemia, and 55 tests are targeted at high priority diseases including HIV, hepatitis B and C, and malaria.

Alexandra York

The Multilateral Initiative on Malaria has a meeting every 3 years. The 7th was held in Diamniadio, Senegal, April 16–20. Alexandra York reports.

John McConnell

Politicians, royalty, and leaders in global health met to discuss how to halve malaria in the Commonwealth by 2023, and to pledge the money to do it. John McConnell reports.

Meta Roestenberg, Marie-Astrid Hoogerwerf, Daniela M Ferreira, Benjamin Mordmüller, Maria Yazdanbakhsh

Controlled human infection (CHI) trials, in which healthy volunteers are experimentally infected, can accelerate the development of novel drugs and vaccines for infectious diseases of global importance. The use of CHI models is expanding from around 60 studies in the 1970s to more than 120 publications in this decade, primarily for influenza, rhinovirus, and malaria. CHI trials have provided landmark data for several registered drugs and vaccines, and have generated unprecedented scientific insights.

Elizabeth A Ashley, Aung Pyae Phyo, Charles J Woodrow

Following unsuccessful eradication attempts there was a resurgence of malaria towards the end of the 20th century. Renewed control efforts using a range of improved tools, such as long-lasting insecticide-treated bednets and artemisinin-based combination therapies, have more than halved the global burden of disease, but it remains high with 445 000 deaths and more than 200 million cases in 2016. Pitfalls in individual patient management are delayed diagnosis and overzealous fluid resuscitation in severe malaria.

Stephen J Rogerson, Meghna Desai, Alfredo Mayor, Elisa Sicuri, Steve M Taylor, Anna M van Eijk

Over the past 10 years, knowledge of the burden, economic costs, and consequences of malaria in pregnancy has improved, and the prevalence of malaria caused by Plasmodium falciparum has declined substantially in some geographical areas. In particular, studies outside of Africa have increased the evidence base of Plasmodium vivax in pregnancy. Rapid diagnostic tests have been poor at detecting malaria in pregnant women, while PCR has shown a high prevalence of low density infection, the clinical importance of which is unknown.

Meghna Desai, Jenny Hill, Silke Fernandes, Patrick Walker, Christopher Pell, Julie Gutman, Kassoum Kayentao, Raquel Gonzalez, Jayne Webster, Brian Greenwood, Michel Cot, Feiko O ter Kuile

Malaria remains one of the most preventable causes of adverse birth outcomes. Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine–pyrimethamine is used to prevent malaria, but resistance to this drug combination has decreased its efficacy and new alternatives are needed. In Africa, a meta-analysis showed three-course or monthly IPTp with sulfadoxine–pyrimethamine to be safe and more effective than the original two-course sulfadoxine–pyrimethamine strategy, prompting WHO to update its policy in 2012.

Paul Joseph Brown

I arrived at the Kasungu District Hospital in the morning and found the grounds outside filled with hundreds of people waiting in the hot sun to be seen by the nurses and doctors. Many had walked for hours from villages in the surrounding rural area to attend the clinic and to be screened for tuberculosis, malaria, and other infectious diseases. Some families were camped next to the hospital. One of the nurses remarked that most of the folks in the waiting area would test positive for malaria, but there were no medications available for them.

John Zarocostas

African leaders launch a continent-wide Zero Malaria Starts with Me campaign to spur response in the face of a setback in progress in the fight against the disease. John Zarocostas reports.

Yoelis Yepes-Pérez, Carolina López, Carlos Fernando Suárez, Manuel Alfonso Patarroyo

by Yoelis Yepes-Pérez, Carolina López, Carlos Fernando Suárez, Manuel Alfonso Patarroyo Malaria is an infectious disease caused by parasites from the genus Plasmodium (P. falciparum and P. vivax are responsible for 90% of all clinical cases); it is widely distributed throughout the world’s tropical and subtropical regions. The P. vivax Pv12 protein is involved in invasion, is expressed on merozoite surface and has been recognised by antibodies from individuals exposed to the disease. In this study, B- and T-cell epitopes from Pv12 were predicted and characterised to advance in the design of a peptide-based vaccine against malaria. For evaluating the humoral response of individuals exposed to natural P. vivax infection from two endemic areas in Colombia, BepiPred-1.0 software was used for selecting B-cell epitopes. B-cell epitope 39038 displayed the greatest recognition by naturally-acquired antibodies and induced an IgG2/IgG4 response. NetMHCIIpan-3.1 prediction software was used for selecting peptides having high affinity binding for HLA-DRβ1* allele lineages and this was confirmed by in-vitro binding assays. T-epitopes 39113 and 39117 triggered a memory T-cell response (Stimulation Index≥2) and significant cytokine production. Combining in-silico, in-vitro and functional assays, two Pv12 protein regions (containing peptides 39038, 39040, 39113 and 39117) have thus been characterised as promising vaccine candidates against P. vivax malaria.

The American Journal of Tropical Medicine and Hygiene

Authors: Potchen MJ, Kampondeni SD, Seydel KB, Haacke EM, Sinyangwe SS, Mwenechanya M, Glover SJ, Milner DA, Zeli E, Hammond CA, Utriainen D, Lishimpi K, Taylor TE, Birbeck GL Abstract The hallmark of pediatric cerebral malaria (CM) is sequestration of parasitized red blood cells in the cerebral microvasculature. Malawi-based research using 0.35 Tesla (T) magnetic resonance imaging (MRI) established that severe brain swelling is associated with fatal CM, but swelling etiology remains unclear. Autopsy and clinical studies suggest several potential etiologies, but limitations of 0.35 T MRI precluded optimal investigations into swelling pathophysiology. A 1.5 T MRI in Zambia allowed for further investigations including susceptibility-weighted imaging (SWI). SWI is an ideal sequence fo...

Abstract Background Malaria is one of the leading causes of death worldwide. This study aimed to determine the trend of malaria among febrile patients seeking treatment over 17 year (1997–2013) at Adi Arkay, Northwest Ethiopia. Methods A 17-year malaria microscopy data were extracted retrospectively at Adi Arkay health centre. Time series and curve estimation analysis were used to evaluate trends in the data. Pearson’s Chi square test was also used to describe associations of variables. Results Over 17 years, 20,483 blood films were requested for malaria diagnosis at the health centre. Out of this, 7428 (36.1%) were microscopically confirmed malaria cases. Plasmodium falciparum, Plasmodium vivax, and their mixed infection accounted for 68.85, 28.79, and 2.34% of all malaria cases, respectively. There was a remarkable reduction of overall malaria during the 17 years. Malaria was reported in all age groups of both sexes, but its positivity rate was significantly higher in males and in the 15–24 years than their counterparts. Conclusion In relative terms, the overall positivity rate of malaria in the area over 17 years showed a significant reduction, but its magnitude as a public health problem is still alarming. Plasmodium falciparum played a significant role in the remarkable drop of overall malaria in the area, whereas vivax malaria remained unchanged. Therefore, control measures should continue to strengthen targeting both predominant malaria parasites in the area.

Abstract Background The decline in the efficacy of artemisinin-based combination treatment (ACT) in some endemic regions threatens the progress towards global elimination of malaria. Molecular surveillance of drug resistance in malaria-endemic regions is vital to detect the emergence and spread of mutant strains. Methods We observed 89 malaria patients for the efficacy of artemether-lumefantrine for the treatment of uncomplicated Plasmodium falciparum infections in Lagos, Nigeria and determined the prevalence of drug resistant strains in the population. Parasite clearance rates were determined by microscopy and the highly sensitive var gene acidic terminal sequence (varATS) polymerase chain reaction for 65 patients with samples on days 0, 1, 3, 7, 14, 21 and 28 after commencement of treatment. The genomic finger print of parasite DNA from pre- and post-treatment samples were determined using 24 nuclear single nucleotide polymorphisms (SNP) barcode for P. falciparum. Drug resistance associated alleles in chloroquine resistance transporter gene (crt-76), multidrug resistance genes (mdr1–86 and mdr1–184), dihydropteroate synthase (dhps-540), dihydrofolate reductase (dhfr-108) and kelch domain (K-13580) were genotyped by high resolution melt analysis of polymerase chain reaction (PCR) fragments. Results By varATS qPCR, 12 (18.5%) of the participants had detectable parasite DNA in their blood three days after treatment, while eight (12.3%) individuals presented with genotypable day 28 parasitaemia. Complexity of infection (CoI) was 1.30 on day 0 and 1.34 on day 28, the mean expected heterozygosity (HE) values across all barcodes were 0.50 ± 0.05 and 0.56 ± 0.05 on days 0 and 28 respectively. Barcode (π) pairwise comparisons showed high genetic relatedness of day 0 and day 28 parasite isolates in three (37.5%) of the eight individuals who presented with re-appearing infections. Crt-76 mutant allele was present in 38 (58.5%) isolates. The mdr1–86 mutant allele was found in 56 (86.2%) isolates. No mutation in the K-13580 was observed. Conclusions Persistence of DNA-detectable parasitaemia in more than 18% of cases after treatment and indications of genetic relatedness between pre- and post-treatment infections warrants further investigation of a larger population for signs of reduced ACT efficacy in Nigeria.

Abstract Background Although the use of induced blood stage malaria infection has proven to be a valuable tool for testing the efficacy of vaccines and drugs against Plasmodium falciparum, a limiting factor has been the availability of Good Manufacturing Practice (GMP)—compliant defined P. falciparum strains for in vivo use. The aim of this study was to develop a cost-effective method for the large-scale production of P. falciparum cell banks suitable for use in clinical trials. Methods Genetically-attenuated parasites (GAP) were produced by targeted deletion of the gene encoding the knob associated histidine rich protein (kahrp) from P. falciparum strain 3D7. A GAP master cell bank (MCB) was manufactured by culturing parasites in an FDA approved single use, closed system sterile plastic bioreactor. All components used to manufacture the MCB were screened to comply with standards appropriate for in vivo use. The cryopreserved MCB was subjected to extensive testing to ensure GMP compliance for a phase 1 investigational product. Results Two hundred vials of the GAP MCB were successfully manufactured. At harvest, the GAP MCB had a parasitaemia of 6.3%, with 96% of parasites at ring stage. Testing confirmed that all release criteria were met (sterility, absence of viral contaminants and endotoxins, parasite viability following cryopreservation, identity and anti-malarial drug sensitivity of parasites). Conclusion Large-scale in vitro culture of P. falciparum parasites using a wave bioreactor can be achieved under GMP-compliant conditions. This provides a cost-effective methodology for the production of malaria parasites suitable for administration in clinical trials.

Fidock D.

Plasmodium falciparummalariavolatile organic compoundsbreath metabolitesbiomarkersdiagnostic teststerpenesmosquito attractants…

Abstract Background Achieving vector control targets is a key step towards malaria elimination. Because of variations in reporting of progress towards vector control targets in 2013, the coverage of these vector control interventions in Namibia was assessed. Methods Data on 9846 households, representing 41,314 people, collected in the 2013 nationally-representative Namibia Demographic and Health Survey were used to explore the coverage of two vector control methods: indoor residual spraying (IRS) and insecticide-treated nets (ITNs). Regional data on Plasmodium falciparum parasite rate in those aged 2–10 years (PfPR2–10), obtained from the Malaria Atlas Project, were used to provide information on malaria transmission intensity. Poisson regression analyses were carried out exploring the relationship between household interventions and PfPR2–10, with fully adjusted models adjusting for wealth and residence type and accounting for regional and enumeration area clustering. Additionally, the coverage as a function of government intervention zones was explored and models were compared using log-likelihood ratio tests. Results Intervention coverage was greatest in the highest transmission areas (PfPR2–10 ≥ 5%), but was still below target levels of 95% coverage in these regions, with 27.6% of households covered by IRS, 32.3% with an ITN and 49.0% with at least one intervention (ITN and/or IRS). In fully adjusted models, PfPR2–10 ≥ 5% was strongly associated with IRS (RR 14.54; 95% CI 5.56–38.02; p 

Abstract Background Plasmodium falciparum malaria is an important cause of morbidity in northern Uganda. This study was undertaken to assess village-, household-, and individual-level risk factors of asymptomatic falciparum malaria in children in 12 villages in northern Uganda. Methods Between 10/2011 and 02/2014, 1006 apparently healthy children under 16 years old were enrolled in 12 villages using a stratified, multi-stage, cluster survey design and assessed for P. falciparum malaria infection using the rapid diagnostic test (RDT) and thick film microscopy (TFM), and structured interviewer-administered questionnaires. Associations between weighted P. falciparum malaria prevalence (pfPR), based on RDT, and covariates were estimated as odds ratios and 95% confidence intervals (ORs, 95% CIs) using logistic models accounting for the survey design. Results Among 942 (93.5%) children successfully tested, pfPR was 52.4% by RDT and 32.7% by TFM. Overall pfPR was lower in villages where indoor residual insecticide spray (IRS) was, versus not, implemented (18.4% versus 75.2%, P 

Jonathan S. Schultz, Adam J. Atherly and Andrés F. Henao-Martínez

Abstract. Uninsured and unprepared travelers to countries with endemic tropical diseases pose great health-care burdens and financial risks on returning to the United States. We discuss the delayed presentation of an uninsured U.S. traveler returning from West Africa with severe malaria who required intensive care measures to save his life. Despite being critically ill on his return, he sat rigoring on his couch taking antipyretics for 3 days, while he applied for insurance on the Affordable Care Act website and waited for approval because he was fearful of the costs of seeking care. He also had limited access to affordable pretravel consultation and prophylactic medications and did not take them because he had no insurance. Average fees for a malaria hospitalization cost $25,789; however, this patient accumulated fees nearing $300,000—and his care was reimbursed by emergency Medicaid with $39,000, because his newly accepted insurance did not cover his hospitalization. This patients’ experience in the U.S. health-care system with a deadly tropical disease exemplifies the need for affordable universal coverage of pretravel consultation and malaria prophylaxis. In this uncertain political time and the recent removal of the health insurance mandate, along with the White House and Congress wanting to reform health care, this case supports the American Society of Tropical Medicine and Hygiene (ASTMH) statements showing the need for funding of tropical medicine education, research, and public health services for travelers, not cuts to important agencies and insurances that keep our country safe from imported deadly tropical diseases.

Abstract Background Given the risk of artemisinin resistance spreading from the Greater Mekong sub-region, prospective monitoring in sub-Saharan Africa should be expedited. Molecular biology techniques used for monitoring rely on the detection of k13 validated mutants by using PCR and Sanger sequencing approach, usually not available in malaria endemic areas. Methods A semi-automated workflow based on the easyMAG® platform and the Argene Solution® (bioMérieux, Marcy l’Etoile, France) as a field-based surveillance tool operable at national level was developed in four steps. Clinical and analytical performances of this tool detecting five of the most frequent and validated k13 mutants (Y493H, I543T, R539T, F446I and C580Y) from dried blood spots (DBS) were compared to the gold standard approach (PCR and Sanger sequencing). Results By using the ARMS (amplification-refractory mutation system) strategy, the best multiplexing options were found in 3 separate real-time PCR duplexes (IC as internal control/I543T, C580Y/Y493H and F446I/R539T) with limits of detection ranging from 50 (C580Y) to 6.25 parasites/µL (Y493H). In field conditions, using 642 clinical DBS (from symptomatic patients and asymptomatic individuals) collected from Cambodia, Myanmar and Africa (Chad), the overall sensitivity and specificity of the K13 bMx prototype assay developed by bioMérieux were ≥ 90%. Areas under the ROC curves were estimated to be > 0.90 for all k13 mutants in samples from symptomatic patients. Conclusion The K13 ready-to-use bMx prototype assay, considered by the end-users as a user-friendly assay to perform (in shorter time than the K13 reference assay) and easy to interpret, was found to require less budget planning and had fewer logistical constraints. Its excellent performance qualifies the prototype as a reliable screening tool usable in malaria endemic countries recognized to be at risk of emergence or spread of validated k13 mutants. Additional multi-site studies are needed to evaluate the performances of the K13 bMx prototype assay in different epidemiological contexts such as Africa, India, or South America.

Abstract Background Radical cure of Plasmodium vivax malaria requires treatment with a blood schizonticide and a hypnozoitocide (primaquine) to eradicate the dormant liver stages. There has been uncertainty about the operational effectiveness and optimum dosing of the currently recommended 14-day primaquine (PQ) course. Methods A two centre, randomized, open-label, two arm study was conducted in South India. Patients were randomized to receive either high dose (0.5 mg base/kg body weight) or conventional dose (0.25 mg/kg) PQ for 14 days. Plasma concentrations of PQ and carboxyprimaquine (CPQ) on the 7th day of treatment were measured by reverse phase high performance liquid chromatography. Study subjects were followed up for 6 months. Recurrent infections were genotyped using capillary fragment length polymorphism of two PCR-amplified microsatellite markers (MS07 and MS 10). Results Fifty patients were enrolled. Baseline characteristics and laboratory features did not differ significantly between the groups. Mean age of the study population was 42 ± 16.0 years. Recurrences 80–105 days later occurred in 4 (8%) patients, two in each the groups. All recurrences had the same microsatellite genotype as that causing the index infection suggesting all were relapses. One relapse was associated with low CPQ concentrations suggesting poor adherence. Conclusions This small pilot trial supports the effectiveness of the currently recommended lower dose (0.25 mg/kg/day) 14 day PQ regimen for the radical cure of vivax malaria in South India. Trial registration Clinical Trials Registry-India, CTRI/2017/03/007999. Registered 3 March 2017, http://ctri.nic.in/Clinicaltrials/regtrial.php?modid=1&compid=19&EncHid=82755.86366.

Vaughan, A. M., Sack, B. K., Dankwa, D., Minkah, N., Nguyen, T., Cardamone, H., Kappe, S. H. I.

Genetically attenuated malaria parasites (GAP) that arrest during liver stage development are powerful immunogens and afford complete and durable protection against sporozoite infection. Late liver stage-arresting GAP provide superior protection against sporozoite challenge in mice when compared to early live stage-arresting attenuated parasites. However, very few late liver stage-arresting GAP have been generated to date. Therefore, identification of additional loci that are critical for late liver stage development and can be used to generate novel late liver stage-arresting GAPs are of importance. We further explored genetic attenuation in Plasmodium yoelii by combining two gene deletions, PlasMei2 and Liver-Specific Protein 2 (LISP2), that each cause late liver stage arrest with varying degrees of infrequent breakthrough to blood stage infection. The dual gene deletion resulted in a synthetic lethal phenotype that caused complete attenuation in a highly susceptible mouse strain. P. yoelii plasmei2–/lisp2– arrested late in liver stage development and did not persist in livers beyond three days after infection. Immunization with this GAP elicited robust protective antibody responses in outbred and inbred mice against sporozoites, liver stages and blood stages as well as eliciting protective liver resident T cells. The immunization afforded protection against both sporozoite challenge and blood stage challenge. These findings provide evidence that completely attenuated late liver stage-arresting GAP are achievable via the synthetic lethal approach and might enable a path forward for the creation of a completely attenuated late liver stage-arresting P. falciparum GAP.

Sabine Dittrich, Latsaniphone Boutthasavong, Dala Keokhamhoung, Weerawat Phuklia, Scott B. Craig, Suhella M. Tulsiani, Mary-Anne Burns, Steven L. Weier, David A. B. Dance, Viengmon Davong, Manivanh Vongsouvath, Mayfong Mayxay, Rattanaphone Phetsouvanh, Paul N. Newton and Kate Woods

Abstract. Leptospirosis is a globally important cause of acute febrile illness, and a common cause of non-malarial fever in Asia, Africa, and Latin America. Simple rapid diagnostic tests (RDTs) are needed to enable health-care workers, particularly in low resource settings, to diagnose leptospirosis early and give timely targeted treatment. This study compared four commercially available RDTs to detect human IgM against Leptospira spp. in a head-to-head prospective evaluation in Mahosot Hospital, Lao PDR. Patients with an acute febrile illness consistent with leptospirosis (N = 695) were included in the study during the 2014 rainy season. Samples were tested with four RDTs: (“Test-it” [Life Assay, Cape Town, South Africa; N = 418]; “Leptorapide” [Linnodee, Ballyclare, Northern Ireland; N = 492]; “Dual Path Platform” [DPP] [Chembio, Medford, NY; N = 530]; and “SD-IgM” [Standard Diagnostics, Yongin, South Korea; N = 481]). Diagnostic performance characteristics were calculated and compared with a composite reference standard combining polymerase chain reaction (PCR) (rrs), microscopic agglutination tests (MATs), and culture. Of all patients investigated, 39/695 (5.6%) were positive by culture, PCR, or MAT. The sensitivity and specificity of the RDTs ranged greatly from 17.9% to 63.6% and 62.1% to 96.8%, respectively. None of the investigated RDTs reached a sensitivity or specificity of > 90% for detecting Leptospira infections on admission. In conclusion, our investigation highlights the challenges associated with Leptospira diagnostics, particularly in populations with multiple exposures. These findings emphasize the need for extensive prospective evaluations in multiple endemic settings to establish the value of rapid tools for diagnosing fevers to allow targeting of antibiotics.

Abstract Background While China is a major manufacturer of artemisinin and its derivatives, it lags as a global leader in terms of the total export value of anti-malarial drugs as finished pharmaceutical products ready for marketing and use by patients. This may be due to the limited number of World Health Organization (WHO) prequalified anti-malarial drugs from China. Understanding the reasons for the slow progress of WHO prequalification (PQ) in China can help improve the current situation and may lead to greater efforts in malaria eradication by Chinese manufacturers. Methods In-depth interviews were conducted in China between November 2014 and December 2016. A total of 26 key informants from central government agencies, pharmaceutical companies, universities, and research institutes were interviewed, all of which had current or previous experience overseeing or implementing anti-malarial research and development in China. Results Chinese anti-malarial drugs that lack WHO PQ are mainly exported for use in the African private market. High upfront costs with unpredictable benefits, as well as limited information and limited technical support on WHO PQ, were reported as the main barriers to obtain WHO PQ for anti-malarial drugs by respondents from Chinese pharmaceutical companies. Potential incentives identified by respondents included tax relief, human resource training and consultation, as well as other incentives related to drug approval, such as China’s Fast Track Channel. Conclusions Government support, as well as innovative incentives and collaboration mechanisms are needed for further adoption of WHO PQ for anti-malarial drugs in China.

Abstract Background Artemether–lumefantrine (AL) and artesunate–amodiaquine are first-line treatment for uncomplicated malaria in many endemic countries, including Mali. Dihydroartemisinin–piperaquine (DHA–PQ) is also an alternative first-line artemisinin-based combination therapy, but only few data are available on DHA–PQ efficacy in sub-Saharan Africa. The main aim of this study was to compare clinical efficacy of DHA–PQ versus AL, using the World Health Organization (WHO) 42-day in vivo protocol. Methods The efficacy of three-dose regimens of DHA–PQ was compared to AL combination in a randomized, comparative open label trial using the WHO 42-day follow-up protocol from 2013 to 2015 in Doneguebougou and Torodo, Mali. The primary endpoint was to access the PCR-corrected Adequate Clinical and Parasitological Responses at day 28. Results A total of 317 uncomplicated malaria patients were enrolled, with 159 in DHA–PQ arm and 158 in AL arm. The parasite positivity rate decreased from 68.4% (95% CI 60.5–75.5) on day 1 to 3.8% (95% CI 1.4–8.1) on day 2 for DHA–PQ and 79.8% (95% CI 72.3–85.7) on day 1 to 9.5% (95% CI 5.4–15.2) on day 2 for AL, (p = 0.04). There was a significant difference in the uncorrected ACPR between DHA–PQ and AL, both at 28-day and 42-day follow-up with 97.4% (95% CI 93.5–99.3) in DHA–PQ vs 84.5% (95% CI 77.8–89.8) in AL (p 

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 Malaria remains a public health problem in Zimbabwe. However, malaria elimination has become a foreseeable prospect with Matabeleland South Province making significant gains towards halting local malaria transmission. This study reviews malaria elimination progress and challenges to date utilizing the World Health Organization’s Malaria Programme Review framework. Results Between 2011 and 2015, malaria incidence was less than one case per 1000 population at risk in all districts save for Beitbridge and Gwanda. The majority of cases were from Beitbridge with local transmission in the same. Incidence declined in Bulilima (p = 0.01), Gwanda (p = 0.72) and Umzingwane (p = 0.44), increasing in Beitbridge (p = 0.35), Insiza (p = 0.79) and Mangwe (p = 0.60). Overall provincial incidence declined although this was not statistically significant. Malaria transmission was bimodal, with a major peak in April and a minor peak in October. A case based malaria surveillance system existed but was not real-time. Foci response guidelines were not domesticated. Artemisinin formed the backbone of case management regimens with primaquine for gametocyte clearance. Indoor residual spraying coverages were below the national target of 95% for rooms targeted for spraying. Conclusion Matabeleland South province has set precedence for targeting sub-national malaria elimination in Zimbabwe. This experience may prove useful for national scale up. There is need to improve surveillance, foci response and intensification of activities to halt residual malaria transmission in Beitbridge District.

The American Journal of Tropical Medicine and Hygiene

Authors: Killeen GF Abstract The term epidemiological entomology was first coined by Garrett-Jones over half a century ago1 but has been out of fashion for far too long.2 In this issue, Sougoufara et al.3 illustrate clearly just how insightful such an approach can be when applied to characterizing key properties of a dynamic malaria transmission system before and after the scale-up of vector control with long-lasting insecticidal nets in Dielmo, Senegal. Using simple analytical models first pioneered by Garrett-Jones himself,4 these authors illustrate how not all may be as it appears based on direct interpretation of entomological data alone. Allowing for the fact that malaria transmission requires both humans and mosquitoes to meet at the same time and place, they show that insect...

The morbidity and mortality that are associated with hepatitis B virus (HBV) infection have been overshadowed by the public health prominence of other infectious diseases, including human immunodeficiency virus (HIV) infection, tuberculosis, and malaria. There is a dawning realization that the……

Abstract Background Anopheles sacharovi is a dominant malaria vector species in South Europe and the Middle East which has a highly plastic behaviour at both adult and larval stages. Such plasticity has prevented this species from eradication by several anti-vector campaigns. The development of new genome-based strategies for vector control will benefit from genome sequencing and physical chromosome mapping of this mosquito. Although a cytogenetic photomap for chromosomes from salivary glands of An. sacharovi has been developed, no cytogenetic map suitable for physical genome mapping is available. Methods Mosquitoes for this study were collected at adult stage in animal shelters in Armenia. Polytene chromosome preparations were prepared from ovarian nurse cells. Fluorescent in situ hybridization (FISH) was performed using PCR amplified probes. Results This study constructed a high-quality standard photomap for polytene chromosomes from ovarian nurse cells of An. sacharovi. Following the previous nomenclature, chromosomes were sub-divided into 39 numbered and 119 lettered sub-divisions. Chromosomal landmarks for the chromosome recognition were described. Using FISH, 4 PCR-amplified genic probes were mapped to the chromosomes. The positions of the probes demonstrated gene order reshuffling between An. sacharovi and Anopheles atroparvus which has not been seen cytologically. In addition, this study described specific chromosomal landmarks that can be used for the cytotaxonomic diagnostics of An. sacharovi based on the banding pattern of its polytene chromosomes. Conclusions This study constructed a high-quality standard photomap for ovarian nurse cell chromosomes of An. sacharovi and validated its utility for physical genome mapping. Based on the map, cytotaxonomic features for identification of An. sacharovi have been described. The cytogenetic map constructed in this study will assist in creating a chromosome-based genome assembly for this mosquito and in developing cytotaxonomic tools for identification of other species from the Maculipennis group.

Abstract Background Malaria chemoprophylaxis options in pregnancy are limited, and atovaquone–proguanil (AP) is not recommended because of insufficient safety evidence. An anonymous, internet-based survey was disseminated to describe outcomes of pregnancies accidentally exposed to AP. Outcomes of interest included miscarriage (defined as pregnancy loss before 20 weeks), stillbirth (defined as pregnancy loss at or after 20 weeks), preterm birth or live birth prior to 37 weeks, and the presence of congenital anomalies. Results A total of 487 women responded and reported on 822 pregnancies. Of the 807 pregnancies with information available on exposure and outcomes, 10 (1.2%) had atovaquone–proguanil exposure, all in the first trimester, and all resulted in term births with no birth defects. Conclusions Use of an anti-malarial not recommended in pregnancy is likely to occur before the woman knows of her pregnancy. This study adds to the limited evidence of the safety of AP in pregnancy. Further study on use of AP in pregnancy should be a high priority, as an alternative option for the prevention of malaria in pregnancy in non-immune travellers is urgently needed.

Abstract Background Nearly half of the world’s population (3.2 billion people) were at risk of malaria in 2015, and resistance to current therapies is a major concern. While the standard of care includes drug combinations, there is a pressing need to identify new combinations that can bypass current resistance mechanisms. In the work presented here, a combined transcriptional drug repositioning/discovery and machine learning approach is proposed. Methods The integrated approach utilizes gene expression data from patient-derived samples, in combination with large-scale anti-malarial combination screening data, to predict synergistic compound combinations for three Plasmodium falciparum strains (3D7, DD2 and HB3). Both single compounds and combinations predicted to be active were prospectively tested in experiment. Results One of the predicted single agents, apicidin, was active with the AC50 values of 74.9, 84.1 and 74.9 nM in 3D7, DD2 and HB3 P. falciparum strains while its maximal safe plasma concentration in human is 547.6 ± 136.6 nM. Apicidin at the safe dose of 500 nM kills on average 97% of the parasite. The synergy prediction algorithm exhibited overall precision and recall of 83.5 and 65.1% for mild-to-strong, 48.8 and 75.5% for moderate-to-strong and 12.0 and 62.7% for strong synergies. Some of the prospectively predicted combinations, such as tacrolimus-hydroxyzine and raloxifene-thioridazine, exhibited significant synergy across the three P. falciparum strains included in the study. Conclusions Systematic approaches can play an important role in accelerating discovering novel combinational therapies for malaria as it enables selecting novel synergistic compound pairs in a more informed and cost-effective manner.

Yerlikaya S, Campillo A, Gonzalez I.

AbstractDespite the increased use and worldwide distribution of malaria rapid diagnostic tests (RDTs) which distinguish between Plasmodium falciparum and non-falciparum species, little is known about their performance for detecting Plasmodium knowlesi (Pk), Plasmodium malariae (Pm), and Plasmodium ovale (Po). The objective of this review is to analyze results of published studies evaluating the diagnostic accuracy of malaria RDTs in detecting Pk, Pm and Po mono-infections.MEDLINE, EMBASE, Web of Science and CENTRAL databases were systematically searched to identify studies which reported on the performance of RDTs in detecting Pk, Pm,Po mono-infections.Among 40 studies included in the review, three reported on Pk, eight on Pm, five on Po, one on Pk and Pm, and 23 on Pm and Po infections. In the meta-analysis, estimates of sensitivities of RDTs in detecting Pk infections ranged from 2% to 48%. Test performances for Pm and Po infections were less accurate and highly heterogeneous, mainly due to the small number of samples tested.Limited data available suggest that malaria RDTs show suboptimal performance for detecting Pk, Pm,Po infections. New improved RDTs as well as appropriately designed, cross-sectional studies to demonstrate their usefulness in the detection of neglected Plasmodium species, are urgently needed.

Wang, W., Huang, P., Jiang, N., Lu, H., Zhang, D., Wang, D., Zhang, K., Wahlgren, M., Chen, Q.

Invasion into erythrocytes of merozoites is required in the life cycle of malarial parasites. Proteins derived from the invasive merozoites are essential ligands for erythrocyte recognition and penetration. In this study, we report a novel protein which possesses a Trx domain-like structure of the thioredoxin family and is expressed on the surface of merozoites of the malaria parasite Plasmodium falciparum. This protein, namely PfTrx-mero protein, displayed a mutated sequence character at the Trx domain, but with a specific binding activity to human erythrocytes. Specific antibodies to the protein inhibited merozoite invasion into human erythrocytes. Immunization of a homologous protein of P. berghei ANKA strain also showed significant protection against lethal infection in mice. These results suggested that the novel PfTrx-like-mero protein expressed on the surface of merozoites is an important ligand participating in erythrocyte invasion and a potential vaccine candidate.

Robert, M. G., Foguim Tsombeng, F., Gendrot, M., Mosnier, J., Amalvict, R., Benoit, N., Torrentino-Madamet, M., Pradines, B., the French National Reference Centre for Imported Malaria Study Group

Resistance to piperaquine has been associated with the amplification of the plasmepsin 2 gene in Cambodia. None of the 175 African isolates that we analyzed had plasmepsin 2 gene amplification (piperaquine inhibitory concentration 50% ranged from 0.94 to 137.5 nM), suggesting a low level of piperaquine reduced susceptibility prevalence in Africa. Additionally, the few isolates with reduced susceptibility to piperaquine did not harbor amplification of the plasmepsin 2 gene.