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Infection and Immunity, Ahead of Print. …

Journal of Medical Virology, Accepted Article.

The SARS-CoV-2 B.1.1.529 (omicron) variant, divided in five lineages (BA.1/BA.2/BA.3/BA.4/BA.5), harbors numerous spike protein mutations particularly in the receptor-binding-domain (RBD). Recent studies showed that the omicron variant resists to the majority of RBD-targeting monoclonal antibodies (mAb) [1]. Sotrovimab, a pan-sarbecovirus neutralizing mAb recently authorized, seems to remain efficient to neutralize omicron variant [1,2]. However, as it targets a single epitope, the risk of developing resistance mutations is not negligible.

We would like to share our concern on the paediatric cases with acute severe hepatitis of unknown aetiology (ASHep-UA) that appeared worldwide in developed countries since October 1, 2021 (1). As of 1 May 2022 over 200 cases have been reported from 17 countries: United Kingdom (145), Italy (17), Spain (13), Israel (12), the United States of America (12), Denmark (6), Ireland (4), the Netherlands (4), Japan (3), Austria (2), Belgium (2), France (2), Norway (2), Germany (1), Poland (1), Romania (1), and Singapore (1) (1, 2).

To compare the homologous prime-boost vaccination scheme of Gam-COVID-Vac (Sputnik V, SpV) to its heterologous combination with mRNA-1273 (Moderna, Mod) vaccine.

Introduction…

Journal of Medical Virology, Accepted Article.

Journal of Medical Virology, Accepted Article.

Journal of Medical Virology, Accepted Article.

Journal of Medical Virology, Accepted Article.

Journal of Medical Virology, Accepted Article.

Journal of Medical Virology, Accepted Article.

As of May 11, 2022, an estimated 519 million individuals have been infected with SARS-CoV-2, and at least 11 billion COVID-19 vaccine doses have been administered worldwide. Therefore, understanding hybrid immunity (ie, immunity derived from infection plus vaccination) is crucial to guide future vaccination policies. We found that vaccination provided additional protection to that induced by past infection during the gamma (P.1) and delta (B.1.617.2) variant waves of the pandemic in Brazil.1 With the emergence of the omicron (B.1.1.529) variant, vaccine effectiveness appears to decay,2,3 but protection in individuals who have been previously infected and vaccinated remains unknown.

One of the many lessons of the past 2 years has been the additional challenges faced by low-income and middle-income countries in accessing and distributing vaccines. Although the major focus has been accessing COVID-19 vaccination,1 ever-mounting evidence exists to suggest that childhood vaccination programmes generally have been disrupted, for a number of reasons, including restrictions of population movement due to national lockdowns early in the COVID-19 pandemic, and later predominantly due to vaccine stockouts.

Rotavac and Rotasiil can be safely used in an interchangeable manner for routine immunisation since the seroresponse was non-inferior in the mixed vaccine regimen compared with the single vaccine regimen. These results allow for flexibility in administering the vaccines, helping to overcome vaccine shortages and supply chain issues, and targeting migrant populations easily.

Our findings provide evidence of post-Ebola virus disease clinical sequelae among contacts with unrecognised Ebola virus disease but not in people with pauci-symptomatic or asymptomatic Ebola virus infection.

Infection and Immunity, Ahead of Print. …

Abstract

Purpose

Symptoms often persistent for more than 4 weeks after COVID-19—now commonly referred to as ‘Long COVID’. Independent of initial disease severity or pathological pulmonary functions tests, fatigue, exertional intolerance and dyspnea are among the most common COVID-19 sequelae. We hypothesized that respiratory muscle dysfunction might be prevalent in persistently symptomatic patients after COVID-19 with self-reported exercise intolerance.

Methods

In a small cross-sectional pilot study (n = 67) of mild-to-moderate (nonhospitalized) and moderate-to-critical convalescent (formerly hospitalized) patients presenting to our outpatient clinic approx. 5 months after acute infection, we measured neuroventilatory activity P0.1, inspiratory muscle strength (PImax) and total respiratory muscle strain (P0.1/PImax) in addition to standard pulmonary functions tests, capillary blood gas analysis, 6 min walking tests and functional questionnaires.

Results

Pathological P0.1/PImax was found in 88% of symptomatic patients. Mean PImax was reduced in hospitalized patients, but reduced PImax was also found in 65% of nonhospitalized patients. Mean P0.1 was pathologically increased in both groups. Increased P0.1 was associated with exercise-induced deoxygenation, impaired exercise tolerance, decreased activity and productivity and worse Post-COVID-19 functional status scale. Pathological changes in P0.1, PImax or P0.1/PImax were not associated with pre-existing conditions.

Conclusions

Our findings point towards respiratory muscle dysfunction as a novel aspect of COVID-19 sequelae. Thus, we strongly advocate for systematic respiratory muscle testing during the diagnostic workup of persistently symptomatic, convalescent COVID-19 patients.

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Antimicrobial Agents and Chemotherapy, Ahead of Print. …

Antimicrobial Agents and Chemotherapy, Ahead of Print. …

Abstract

Background

Interactions between humans and animals are the key elements of zoonotic spillover leading to zoonotic disease emergence. Research to understand the high-risk behaviors associated with disease transmission at the human-animal interface is limited, and few consider regional and local contexts.

Objective

This study employed an integrated behavioral–biological surveillance approach for the early detection of novel and known zoonotic viruses in potentially high-risk populations, in an effort to identify risk factors for spillover and to determine potential foci for risk-mitigation measures.

Method

Participants were enrolled at two community-based sites (n = 472) in eastern and western Thailand and two hospital (clinical) sites (n = 206) in northeastern and central Thailand. A behavioral questionnaire was administered to understand participants’ demographics, living conditions, health history, and animal-contact behaviors and attitudes. Biological specimens were tested for coronaviruses, filoviruses, flaviviruses, influenza viruses, and paramyxoviruses using pan (consensus) RNA Virus assays.

Results

Overall 61/678 (9%) of participants tested positive for the viral families screened which included influenza viruses (75%), paramyxoviruses (15%), human coronaviruses (3%), flaviviruses (3%), and enteroviruses (3%). The most salient predictors of reporting unusual symptoms (i.e., any illness or sickness that is not known or recognized in the community or diagnosed by medical providers) in the past year were having other household members who had unusual symptoms and being scratched or bitten by animals in the same year. Many participants reported raising and handling poultry (10.3% and 24.2%), swine (2%, 14.6%), and cattle (4.9%, 7.8%) and several participants also reported eating raw or undercooked meat of these animals (2.2%, 5.5%, 10.3% respectively). Twenty four participants (3.5%) reported handling bats or having bats in the house roof. Gender, age, and livelihood activities were shown to be significantly associated with participants’ interactions with animals. Participants’ knowledge of risks influenced their health-seeking behavior.

Conclusion

The results suggest that there is a high level of interaction between humans, livestock, and wild animals in communities at sites we investigated in Thailand. This study highlights important differences among demographic and occupational risk factors as they relate to animal contact and zoonotic disease risk, which can be used by policymakers and local public health programs to build more effective surveillance strategies and behavior-focused interventions.

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Abstract

Background

The present study aimed to identify the clinical significance of Mycoplasma pneumoniae (MP)-specific immunoglobulin M (IgM) titer, in addition to a diagnosis of MP infection, in children with MP pneumonia.

Methods

This study was performed in 155 children hospitalized with MP pneumonia. The clinical features and laboratory and radiographic findings on admission in children with positive or negative MP-specific IgM titers were retrospectively reviewed from the electronic medical records.

Results

The mean age of the included children was 6.0 years, and 118 (76.1%) of the children were positive for MP-specific IgM. A longer duration between symptom onset and admission (adjusted odds ratio [aOR] 1.47, 95% confidence interval [CI] 1.24–1.75), longer duration of symptoms during the illness (aOR 1.15, 95% CI 1.02–1.30), and development of extra-pulmonary manifestations (aOR 9.16, 95% CI 1.96–42.81) were significantly associated with a positive MP-specific IgM titer. Serum lactate dehydrogenase levels (aOR 1.00, 95% CI 1.00–1.01) and pneumonic infiltration involving > 50% of the total lung volume on chest radiography (aOR 4.68, 95% CI 1.12–19.55) were associated with positive MP-specific IgM in children with MP pneumonia. A poor response to stepwise treatment for MP pneumonia was more common in children with a positive MP-specific IgM titer than those with a negative MP-specific IgM titer on admission.

Conclusions

A positive MP-specific IgM titer at diagnosis of MP pneumonia may partially suggest an exaggerated immune response with a higher disease burden compared to children with MP pneumonia with a negative MP-specific IgM titer.

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Abstract

Background

Symptoms of depression are prevalent in people living with human immune deficiency virus/acquired immune deficiency syndrome (PLWHA), and worsened by lack of physical activity/exercises, leading to restriction in social participation/functioning. This raises the question: what is the extent to which physical exercise training affected, symptoms of depression, physical activity level (PAL) and social participation in PLWHA compared to other forms of intervention, usual care, or no treatment controls?

Method

Eight databases were searched up to July 2020, according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol. Only randomised controlled trials involving adults who were either on HAART/HAART-naïve and reported in the English language, were included. Two independent reviewers determined the eligibility of the studies, extracted data, assessed their quality, and risk of bias using the Physiotherapy Evidence Database (PEDro) tool. Standardised mean difference (SMD) was used as summary statistics for the mean primary outcome (symptoms of depression) and secondary outcomes (PAL and social participation) since different measuring tools/units were used across the included studies. Summary estimates of effects were determined using a random-effects model (I2).

Results

Thirteen studies met the inclusion criteria with 779 participants (n = 596 participants at study completion) randomised into the study groups, comprising 378 males, 310 females and 91 participants with undisclosed gender, and with an age range of 18–86 years. Across the studies, aerobic or aerobic plus resistance exercises were performed 2–3 times/week, at 40–60 min/session, and for between 6-24 weeks, and the risk of bias vary from high to low. Comparing the intervention to control groups showed significant difference in the symptoms of depression (SMD = − 0.74, 95% confidence interval (CI) − 1.01, − 0.48, p ≤ 0.0002; I2 = 47%; 5 studies; 205 participants) unlike PAL (SMD = 0.98, 95% CI − 0.25, 2.17, p = 0.11; I2 = 82%; 2 studies; 62 participants) and social participation (SMD = 0.04, 95% CI − 0.65, 0.73, p = 0.91; I2 = 90%; 6 studies; 373 participants).

Conclusion

Physical exercise training could have an antidepressant-like effect in PLWHA but did not affect PAL and social participation. However, the high heterogeneity in the included studies, implies that adequately powered randomised controlled trials with clinical/methodological similarity are required in future studies.

Trail Registration number

INPLASY202040048.

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Abstract

Background

It is not known whether post-traumatic stress disorder (PTSD) increases HIV-risk behaviours among young people in sub-Saharan Africa. We assessed associations of PTSD symptoms with sexual behaviour, HIV risk perception, and attitudes towards PrEP among young people taking part in the CHAPS community survey. We hypothesised that PTSD symptoms would increase sexual behaviours associated with HIV risk, hinder PrEP uptake and influence preference for daily versus on-demand PrEP.

Methods

Young people without HIV, aged 13–24 years, were purposively recruited in Johannesburg and Cape Town in South Africa, Wakiso in Uganda, and Chitungwiza in Zimbabwe, and surveyed on socio-demographic characteristics, PrEP knowledge and attitudes, sexual behaviour, HIV perception and salience, and mental health. PTSD symptoms were measured using the Primary Care PTSD Screen for the Diagnostic and Statistical Manual of Mental Disorders 5 (PC-PTSD-5). Logistic and ordinal logistic regression was used to assess associations between PC-PTSD-5 score and socio-demographic characteristics, sexual behaviour, HIV risk perception, PrEP attitudes, and substance use, adjusting for age, sex, setting, depression and anxiety.

Results

Of 1330 young people (51% male, median age 19 years), 522 (39%) reported at least one PTSD symptom. There was strong evidence that having a higher PC-PTSD-5 score was associated with reported forced sex (OR 3.18, 95%CI: 2.05–4.93), self-perception as a person who takes risks (OR 1.12, 95%CI: 1.04–1.20), and increased frequency of thinking about risk of HIV acquisition (OR 1.16, 95%CI: 1.08–1.25). PTSD symptoms were not associated with willingness to take PrEP, preference for on-demand versus daily PrEP, or actual HIV risk behaviour such as condomless sex.

Conclusions

Symptoms consistent with probable PTSD were common among young people in South Africa, Uganda and Zimbabwe but did not impact PrEP attitudes or PrEP preferences. Evaluation for PTSD might form part of a general assessment in sexual and reproductive health services in these countries. More work is needed to understand the impact of PTSD on HIV-risk behaviour, forced sex and response to preventive strategies including PrEP.

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Abstract

Background

Adolescent girls and young women (AGYW) account for a disproportionate number of new HIV infections worldwide. HIV prevalence among young sex workers in Uganda is 22.5%. Although pre-exposure prophylaxis (PrEP) is a highly effective biomedical HIV prevention method, awareness of PrEP among AGYW in Uganda has not been studied systematically. We aimed to assess awareness of PrEP and factors associated with awareness of PrEP among AGYW who frequently reported paid sex.

Methods

We conducted a cross-sectional study among 14–24-year old AGYW at high risk of HIV infection in Kampala, Uganda from January to October 2019. Participants were screened for PrEP eligibility using a national screening tool of whom 82.3% were eligible. Data on socio-demographics, behavioral and sexual risks were collected by interview. Awareness of oral or injectable PrEP, the latter of which is currently in late-stage trials, was defined as whether an individual had heard about PrEP as an HIV prevention method. Multivariable robust poisson regression model was used to assess factors associated with oral PrEP awareness.

Results

We enrolled 285 participants of whom 39.3% were under 20 years old, 54.7% had completed secondary education, 68.8% had multiple sex partners in the past 3 months, 8.8% were screened as high risk drinkers’/ alcohol dependent (AUDIT tool) and 21.0% reported sex work as main occupation. Only 23.2% were aware of oral PrEP and 3.9% had heard about injectable PrEP. The prevalence of oral PrEP awareness was significantly higher among volunteers screened as alcohol dependents (aPR 1.89, 95% CI 1.08–3.29) and those with multiple sexual partners (aPR 1.84, 95% CI 1.01–3.35), but was lower among those who reported consistent condom use with recent sexual partners (aPR 0.58, 95% CI 0.37–0.91).

Conclusions

Majority of AGYW were not aware of any kind of PrEP. Those with higher risk behavior, i.e. alcohol dependents or multiple sexual partners, were more aware of oral PrEP. Interventions to increase awareness among female youth are needed. Improving PrEP awareness is critical to increasing PrEP uptake among high-risk AGYW in Uganda.

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Abstract

Background

Vaccination has been proven to be an effective approach against the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to determine the acceptance rate and factors influencing acceptance of COVID-19 vaccination among people living with HIV (PLWH) in Guangxi, China.

Methods

A cross-sectional survey was carried out in five cities in Guangxi, China from May 7 to June 1, 2021. Questionnaires on the acceptance of COVID-19 vaccination and the related factors were conducted among PLWH recruited by simple random sampling. Univariate and multivariate logistic regression analyses were performed to identify factors associated with acceptance of COVID-19 vaccination.

Results

Of all valid respondents (n = 903), 72.9% (n = 658) were willing to receive COVID-19 vaccination. Fear of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was the main reason for being willing to receive vaccination (76.0%), while the main reasons for not willing were the concerns about vaccine safety (54.7%) and the vaccination’s effect on antiretroviral therapy (ART) (50.6%). The most important factors influencing acceptance were the perception that vaccination is unsafe for HIV-infected people (aOR = 0.082, 95% CI = 0.024–0.282) and the poor efficacy in preventing SARS-CoV-2 infection in HIV-infected people (aOR = 0.093, 95% CI = 0.030–0.287). Other factors associated with acceptance included Zhuang ethnicity (aOR = 1.653, 95% CI = 1.109–2.465), highest education level of middle school, high school or above (aOR = 1.747, 95% CI = 1.170–2.608; aOR = 2.492, 95% CI = 1.326–4.682), and the vaccination having little effect on ART efficacy (aOR = 2.889, 95% CI = 1.378–6.059).

Conclusions

Acceptance rate of the COVID-19 vaccination is relatively low among PLWH compared to the general population in China, although some patients refused vaccination due to concerns about vaccine safety and vaccination affecting ART efficacy. More research is needed to investigate the impact of the COVID-19 vaccines on ART efficacy and the effectiveness in preventing SARS-CoV-2 infection among PLWH.

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Abstract

Background

There is no consensus on the optimal secondary antifungal prophylaxis (SAP) regimen in patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT). The purpose of this study was to evaluate the efficacy and safety of posaconazole oral suspension as secondary prophylaxis of invasive fungal disease (IFD) for allo-HSCT patients.

Methods

We retrospectively reviewed clinical data from prior IFD patients who received posaconazole oral suspension as systemic antifungal prophylaxis between June 2016 and January 2021 and have a follow-up period of 1 year after HSCT. The clinical outcomes of patients with a prior history of IFD (n = 30) and those without (n = 93) were compared.

Results

The 1-year cumulative incidence of prophylaxis failure was 58.3% in the group with prior history of IFD and 41.6% in the group without a prior history of IFD (p = 0.459). The cumulative incidence of proven, probable or possible IFD within 1 year after allo-HSCT was 23.1% in the group with prior history of IFD and 14.1% in the group without prior history of IFD (p = 0.230). There was no significant difference between the cumulative incidence of proven or probable IFD within 1-year after allo-HSCT in the group with a prior history of IFD and the group without (p = 0.807). Multivariate logistic regression revealed cytomegalovirus disease as risk factor for post-transplantation IFD occurrence in posaconazole oral suspension prophylaxis. There was not a significant difference in overall survival between the patients with IFD history and those without (P = 0.559).

Conclusions

Our study support that allo-HSCT recipients with a prior history of IFD and normal GI absorption can choose posaconazole oral suspension as a safe and effective SAP option.

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Abstract

Background

Since the beginning of the pandemic, hospitals have been constantly overcrowded, with several observed waves of infected cases and hospitalisations. To avoid as much as possible this situation, efficient tools to facilitate the diagnosis of COVID-19 are needed.

Objective

To evaluate and compare prediction models to diagnose COVID-19 identified in a systematic review published recently using performance indicators such as discrimination and calibration measures.

Methods

A total of 1618 adult patients present at two Emergency Department triage centers and for whom qRT-PCR tests had been performed were included in this study. Six previously published models were reconstructed and assessed using diagnostic tests as sensitivity (Se) and negative predictive value (NPV), discrimination (Area Under the Roc Curve (AUROC)) and calibration measures. Agreement was also measured between them using Kappa’s coefficient and IntraClass Correlation Coefficient (ICC). A sensitivity analysis has been conducted by waves of patients.

Results

Among the 6 selected models, those based only on symptoms and/or risk exposure were found to be less efficient than those based on biological parameters and/or radiological examination with smallest AUROC values (< 0.80). However, all models showed good calibration and values above > 0.75 for Se and NPV but poor agreement (Kappa and ICC < 0.5) between them. The results of the first wave were similar to those of the second wave.

Conclusion

Although quite acceptable and similar results were found between all models, the importance of radiological examination was also emphasized, making it difficult to find an appropriate triage system to classify patients at risk for COVID-19.

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Abstract

Background

Acute respiratory infections (ARIs) and severe acute respiratory illness (SARI) are public health burdens globally. The percentage of non-SARS CoV-2 respiratory viruses among patients having ARI and SARI who visit Car Nicobar's hospital settings is undocumented. Changes in the epidemiology of other respiratory viruses during COVID19 pandemic is being reported worldwide.

Methods

Inpatient and outpatient settings at BJR hospital, Car Nicobar Island, India, were used to conduct prospective monitoring for ARI and SARI among Nicobarese tribal members. The patients with ARI and SARI were enlisted in BJR hospital from June 2019 to May 2021. At the ICMR-NIV in Pune, duplex RT-PCR assays were used to test the presence of respiratory viruses. The prevalence of non- SARS CoV-2 respiratory viruses was measured by comparing here between pandemic and pre-pandemic periods.

Results

During the COVID19 pandemic, Influenza A (H3N2) and rhinovirus were predominantly reported non-SARS CoV-2 respiratory viruses while Human metapneumovirusand influenza A (H1N1)pdm09were most commonly reported in the prepandemic period. This result indicates the altered circulation of non-SARS CoV-2 during pandemic.

Conclusions

A considerable proportion of respiratory infection was correlated with respiratory viruses. Prevalence of non-SARS CoV-2 respiratory viruses was high at the time of infection when compared with pre-pandemic period, at Car Nicobar Island. This study enlightened the change in circulation of other respiratory viruses among the indigenous Nicobarese tribes. Clinicians and allied medical staff should be more prudent of these respiratory infections.

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Abstract

Background

Weather fluctuation affects the incidence of malaria through a network of causuative pathays. Globally, human activities have ultered weather conditions over time, and consequently the number of malaria cases. This study aimed at determining the influence of humidity, temperature and rainfall on malaria incidence in an inland (Muyuka) and a coastal (Tiko) settings for a period of seven years (2011–2017) as well as predict the number of malaria cases two years after (2018 and 2019).

Methods

Malaria data for Muyuka Health District (MHD) and Tiko Health District (THD) were obtained from the Regional Delegation of Public Health and Tiko District Health service respectively. Climate data for MHD was obtained from the Regional Delegation of Transport while that of THD was gotten from Cameroon Development Coorporation. Spearman rank correlation was used to investigate the relationship between number of malaria cases and the weather variables and the simple seasonal model was used to forecast the number of malaria cases for 2018 and 2019.

Results

The mean monthly rainfall, temperature and relative humidity for MHD were 200.38 mm, 27.050C, 82.35% and THD were 207.36 mm, 27.57 °C and 84.32% respectively, with a total number of malaria cases of 56,745 and 40,160. In MHD, mean yearly humidity strongly correlated negatively with number of malaria cases (r = − 0.811, p = 0.027) but in THD, a moderate negative yearly correlation was observed (r = − 0.595, p = 0.159). In THD, the mean seasonal temperature moderately correlated (r = 0.599, p = 0.024) positively with the number of malaria cases, whereas MHD had a very weak negative correlation (r = − 0.174, p = 0.551). Likewise mean seasonal rainfall in THD moderately correlated (r = − 0.559, p = 0.038) negatively with malaria cases, contrary to MHD which showed a very weak positive correlation (r = 0.425, p = 0.130). The simple seasonal model predicted 6,842 malaria cases in Muyuka, for 2018 and same number for 2019, while 3167 cases were observed in 2018 and 2848 in 2019. Also 6,738 cases of malaria were predicted for MHD in 2018 likewise 2019, but 7327 cases were observed in 2018 and 21,735 cases in 2019.

Conclusion

Humidity is the principal climatic variable that negatively influences malaria cases in MHD, while higher seasonal temperatures and lower seasonal rain fall significantly increase malaria cases in THD.

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Abstract

Background

Most non-clinic based HIV pre-exposure prophylaxis (PrEP) programs require fingersticks to self-collect blood specimens for laboratory monitoring, a technique that often results in inadequate blood volume for quantitative syphilis and HIV serological testing. We evaluated the acceptability and feasibility of using the Tasso OnDemand™ device as a self-sampling method for PrEP monitoring tests and compared results from samples obtained using the Tasso device to clinician-collected blood samples.

Methods

We enrolled study subjects online and in a sexual health clinic and HIV clinic in Seattle, WA, USA to assess the acceptability of blood self-sampling and preferences for home-based PrEP monitoring. We compared HIV antigen/antibody, quantitative rapid plasma reagin and creatinine results in paired self-collected and clinical specimens collected from a subset of participants.

Results

Of 141 participants, 124 (88%) were interested in collecting samples for PrEP monitoring at home. Among 48 who completed blood collections, 94% found the Tasso device easy to use and 95% felt they could perform self-sampling at home. Of 27 participants who used two devices, 100% collected sufficient blood to perform up to two tests while 33% collected sufficient serum for three tests. Agreement in test results between paired samples was high.

Conclusions

These pilot data suggest that using the Tasso self-collection device is acceptable and could feasibly be used to obtain serum specimens sufficient for guideline-recommended PrEP monitoring, though use of a larger volume device may be preferable.

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Abstract

Background

Prospective observational data show that infected persons with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain polymerase chain reaction (PCR) positive for a prolonged duration, and that detectable antibodies develop slowly with time. We aimed to analyze how these effects can bias key epidemiological metrics used to track and monitor SARS-CoV-2 epidemics.

Methods

An age-structured mathematical model was constructed to simulate progression of SARS-CoV-2 epidemics in populations. PCR testing to diagnose infection and cross-sectional surveys to measure seroprevalence were also simulated. Analyses were conducted on simulated outcomes assuming a natural epidemic time course and an epidemic in presence of interventions.

Results

The prolonged PCR positivity biased the epidemiological measures. There was a lag of 10 days between the true epidemic peak and the actually-observed peak. Prior to epidemic peak, PCR positivity rate was twofold higher than that based only on current active infection, and half of those tested positive by PCR were in the prolonged PCR positivity stage after infection clearance. Post epidemic peak, PCR positivity rate poorly predicted true trend in active infection. Meanwhile, the prolonged PCR positivity did not appreciably bias estimation of the basic reproduction number R0. The time delay in development of detectable antibodies biased measured seroprevalence. The actually-observed seroprevalence substantially underestimated true prevalence of ever infection, with the underestimation being most pronounced around epidemic peak.

Conclusions

Caution is warranted in interpreting PCR and serological testing data, and any drawn inferences need to factor the effects of the investigated biases for an accurate assessment of epidemic dynamics.

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Abstract

Background

Patients with COVID-19 infection are commonly reported to have an increased risk of venous thrombosis. The choice of anti-thrombotic agents and doses are currently being studied in randomized controlled trials and retrospective studies. There exists a need for individualized risk stratification of venous thromboembolism (VTE) to assist clinicians in decision-making on anticoagulation. We sought to identify the risk factors of VTE in COVID-19 patients, which could help physicians in the prevention, early identification, and management of VTE in hospitalized COVID-19 patients and improve clinical outcomes in these patients.

Method

This is a multicenter, retrospective database of four main health systems in Southeast Michigan, United States. We compiled comprehensive data for adult COVID-19 patients who were admitted between 1st March 2020 and 31st December 2020. Four models, including the random forest, multiple logistic regression, multilinear regression, and decision trees, were built on the primary outcome of in-hospital acute deep vein thrombosis (DVT) and pulmonary embolism (PE) and tested for performance. The study also reported hospital length of stay (LOS) and intensive care unit (ICU) LOS in the VTE and the non-VTE patients. Four models were assessed using the area under the receiver operating characteristic curve and confusion matrix.

Results

The cohort included 3531 admissions, 3526 had discharge diagnoses, and 6.68% of patients developed acute VTE (N = 236). VTE group had a longer hospital and ICU LOS than the non-VTE group (hospital LOS 12.2 days vs. 8.8 days, p < 0.001; ICU LOS 3.8 days vs. 1.9 days, p < 0.001). 9.8% of patients in the VTE group required more advanced oxygen support, compared to 2.7% of patients in the non-VTE group (p < 0.001). Among all four models, the random forest model had the best performance. The model suggested that blood pressure, electrolytes, renal function, hepatic enzymes, and inflammatory markers were predictors for in-hospital VTE in COVID-19 patients.

Conclusions

Patients with COVID-19 have a high risk for VTE, and patients who developed VTE had a prolonged hospital and ICU stay. This random forest prediction model for VTE in COVID-19 patients identifies predictors which could aid physicians in making a clinical judgment on empirical dosages of anticoagulation.

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Abstract

Background

With the decline in local malaria transmission in Vietnam as a result of the National Malaria Control Program (NMCP) elimination activities, a greater focus on the importation and potential reintroduction of transmission are essential to support malaria elimination objectives.

Methods

We conducted a multi-method assessment of the demographics, epidemiology, and clinical characteristics of imported malaria among international laborers returning from African or Southeast Asian countries to Vietnam. Firstly, we conducted a retrospective review of hospital records of patients from January 2014 to December 2016. Secondly, we conducted a mixed-methods prospective study for malaria patients admitted to the study sites from January 2017 to May 2018 using a structured survey with blood sample collection for PCR analysis and in-depth interviews. Data triangulation of the qualitative and quantitative data was used during analysis.

Results

International laborers were young (median age 33.0 years IQR 28.0–39.5 years), predominantly male (92%) adults returning mostly from the African continent (84%) who stayed abroad for prolonged periods (median time 13.5 months; IQR 6.0–331.5 months) and were involved in occupations that exposed them to a higher risk of malaria infection. Epidemiological trends were also similar amongst study strands and included the importation of Plasmodium falciparum primarily from African countries and P. vivax from Southeast Asian countries. Of 11 P. malariae and P. ovale infections across two study strands, 10 were imported from the African continent. Participants in the qualitative arm demonstrated limited knowledge about malaria prior to travelling abroad, but reported knowledge transformation through personal or co-worker’s experience while abroad. Interestingly, those who had a greater understanding of the severity of malaria presented to the hospital for treatment sooner than those who did not; median of 3 days (IQR 2.0–7.0 days) versus 5 days (IQR 4.0–9.5 days) respectively.

Conclusion

To address the challenges to malaria elimination raised by a growing Vietnamese international labor force, consideration should be given to appropriately targeted interventions and malaria prevention strategies that cover key stages of migration including pre-departure education and awareness, in-country prevention and prophylaxis, and malaria screening upon return.

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