The American Journal of Tropical Medicine and Hygiene - Current Issue

The COVID-19 pandemic has had a severe impact worldwide. Developed countries, such as the United States, United Kingdom, Italy, and Spain, had their highly efficient medical infrastructure greatly stressed and suffered from high death tolls. Similarly, Bangladesh, a poverty-stricken South Asian country, is losing its battle against the pandemic, but mainly because of its incompetent healthcare system. The casualties are escalating and public sufferings are becoming unimaginable. On this backdrop, this perspective piece discusses the healthcare crisis in Bangladesh during the pandemic. This article also identifies three responsible issues for the country’s deteriorating health care: 1) poor governance and increased corruption, 2) inadequate healthcare facilities, and 3) weak public health communication.

The COVID-19 pandemic has brought concurrent challenges. The increased incidence of fake and falsified product distribution is one of these problems with tremendous impact, especially in low- and middle-income countries. Up to a tenth of medicines including antibiotics and antimalarial drugs in the African market are considered falsified. Pandemics make this worse by creating an ecosystem of confusion, distraction, and vulnerability stemming from the pandemic as health systems become more stressed and the workload of individuals increased. These environments create opportunities for substandard and falsified medicines to be more easily introduced into the marketplace by unscrupulous operators. In this work we discuss some of the challenges with fake or falsified product distribution in the context of COVID-19 and proposed strategies to best manage this problem.

As the global COVID-19 pandemic continues, unabated and clinical trials demonstrate limited effective pharmaceutical interventions, there is a pressing need to accelerate treatment evaluations. Among options for accelerated development is the evaluation of drug combinations in the absence of prior monotherapy data. This approach is appealing for a number of reasons. First, combining two or more drugs with related or complementary therapeutic effects permits a multipronged approach addressing the variable pathways of the disease. Second, if an individual component of a combination offers a therapeutic effect, then in the absence of antagonism, a trial of combination therapy should still detect individual efficacy. Third, this strategy is time saving. Rather than taking a stepwise approach to evaluating monotherapies, this strategy begins with testing all relevant therapeutic options. Finally, given the severity of the current pandemic and the absence of treatment options, the likelihood of detecting a treatment effect with combination therapy maintains scientific enthusiasm for evaluating repurposed treatments. Antiviral combination selection can be facilitated by insights regarding SARS-CoV-2 pathophysiology and cell cycle dynamics, supported by infectious disease and clinical pharmacology expert advice. We describe a clinical evaluation strategy using adaptive combination platform trials to rapidly test combination therapies to treat COVID-19.

Polio is a deadly viral disease that has been paralyzing many children in Afghanistan. Despite fundamental efforts, primarily vaccination, to reduce the number of cases in Afghanistan, there are still many children who are deprived of the vaccine every year. Afghanistan is one of the two remaining countries endemic for polio, and the country has undergone various challenges that have hampered the eradication of this disease. The underlying challenges include inaccessibility of unsecured areas, illiteracy, refusal, and, most recently, COVID-19. The country is in the midst of a battle against COVID-19, and polio has almost entirely been neglected. Sadly, polio cases are increasing in the country, particularly in polio-free provinces. After an initial lockdown, many businesses have been allowed to resume, but the mass polio vaccination campaign has not restarted. New cases of polio will surge if endemic regions remain unvaccinated or inaccessible. To curb the further spread of polio, Afghanistan needs to resume nationwide house-to-house vaccination as restrictions due to COVID-19 are loosened.

The government of Nigeria ordered closure of schools to slow the spread of COVID-19 when the pandemic hit the country. About 5 months into the outbreak, secondary schools have been reopened to allow students to write their terminal examinations. Many state governments and school owners are fumigating their schools as a way of disinfecting the school environment and ensuring safe resumption of academic activities. We discuss the undue attention given to fumigation in this instance and stress the importance of addressing more beneficial and sustainable strategies to prevent COVID-19 in Nigerian schools.

Large-scale control efforts in sub-Saharan Africa may leave long-term lingering transmission. Large-scale screening of snail infection prevalence by loop-mediated isothermal amplification will enable accurate determination of man-to-snail transmission, as well as the effects of biota in snail habitat on host capacity and thus on snail-to-man transmission. Next-generation sequencing will enable identification of gut content of snails and thus their feeding preferences in hot spots and in non–hot spots, as well as for identification of attractive vegetation types for attracting snails to molluscicides.

By sustaining transmission or causing malaria outbreaks, imported malaria undermines malaria elimination efforts. Few studies have examined the impact of travel on malaria epidemiology. We conducted a literature review and meta-analysis of studies investigating travel as a risk factor for malaria infection in sub-Saharan Africa using PubMed. We identified 22 studies and calculated a random-effects meta-analysis pooled odds ratio (OR) of 3.77 (95% CI: 2.49–5.70), indicating that travel is a significant risk factor for malaria infection. Odds ratios were particularly high in urban locations when travel was to rural areas, to more endemic/high transmission areas, and in young children. Although there was substantial heterogeneity in the magnitude of association across the studies, the pooled estimate and directional consistency support travel as an important risk factor for malaria infection.

Snakebite envenoming is a neglected, public health problem in tropical and subtropical regions. Local tissue necrosis, neurotoxic, and hemo-vasculotoxic effects are well-recognized features, whereas the endocrine and metabolic derangements are not as well known. In addition to contributing to morbidity, some of these manifestations can be potentially life-threatening if not recognized early. The most prominent endocrine manifestation is hypopituitarism (HP), which can manifest acutely or remain asymptomatic and present years later. Unexplained recurrent hypoglycemia and refractory hypotension are early clinical clues to suspect corticotroph axis involvement in acute settings. Chronic pituitary failure may present, like Sheehan’s syndrome, several years after the bite. The occurrence of acute kidney injury, capillary leak syndrome, and disseminated intravascular coagulation are predictors of HP. Adrenal hemorrhages are documented in autopsy series; however, primary adrenal insufficiency is very rare and confounded by the presence of HP. Hyponatremia, hypokalemia or hyperkalemia, and dysglycemia can occur, but the mechanisms involved are only partially understood. Awareness, a high index of suspicion, correct interpretation of hormonal parameters, and timely treatment of these abnormalities can be lifesaving.

Recurrent enteric infections and micronutrient deficiencies, including deficiencies in the tryptophan–kynurenine–niacin pathway, have been associated with environmental enteric dysfunction, potentially contributing to poor child growth and development. We are conducting a randomized, placebo-controlled, 2 × 2 factorial interventional trial in a rural population in Haydom, Tanzania, to determine the effect of 1) antimicrobials (azithromycin and nitazoxanide) and/or 2) nicotinamide, a niacin vitamer, on attained length at 18 months. Mother/infant dyads were enrolled within 14 days of the infant’s birth from September 2017 to September 2018, with the follow-up to be completed in February 2020. Here, we describe the baseline characteristics of the study cohort, risk factors for low enrollment weight, and neonatal adverse events (AEs). Risk factors for a low enrollment weight included being a firstborn child (−0.54 difference in weight-for-age z-score [WAZ] versus other children, 95% CI: −0.71, −0.37), lower socioeconomic status (−0.28, 95% CI: −0.43, −0.12 difference in WAZ), and birth during the preharvest season (November to March) (−0.22, 95% CI: −0.33, −0.11 difference in WAZ). The most common neonatal serious AEs were respiratory tract infections and neonatal sepsis (2.2 and 1.4 events per 100 child-months, respectively). The study cohort represents a high-risk population for whom interventions to improve child growth and development are urgently needed. Further analyses are needed to understand the persistent impacts of seasonal malnutrition and the interactions between seasonality, socioeconomic status, and the study interventions.

Enteric infections early in life have been associated with poor linear growth among children in low-resource settings. Point-of-use water treatment technologies provide effective and low-cost solutions to reduce exposure to enteropathogens from drinking water, but it is unknown whether the use of these technologies translates to improvements in child growth. We conducted a community-based randomized controlled trial of two water treatment technologies to estimate their effects on child growth in Limpopo, South Africa. We randomized 404 households with a child younger than 3 years to receive a silver-impregnated ceramic water filter, a silver-impregnated ceramic tablet, a safe-storage water container alone, or no intervention, and these households were followed up quarterly for 2 years. We estimated the effects of the interventions on linear and ponderal growth, enteric infections assessed by quantitative molecular diagnostics, and diarrhea prevalence. The silver-impregnated ceramic water filters and tablets consistently achieved approximately 1.2 and 3 log reductions, respectively, in total coliform bacteria in drinking water samples. However, the filters and tablets were not associated with differences in height (height-for-age z-score differences compared with no intervention: 0.06, 95% CI: −0.29, 0.40, and 0.00, 95% CI: −0.35, 0.35, respectively). There were also no effects of the interventions on weight, diarrhea prevalence, or enteric infections. Despite their effectiveness in treating drinking water, the use of the silver-impregnated ceramic water filters and tablets did not reduce enteric infections or improve child growth. More transformative water, sanitation, and hygiene interventions that better prevent enteric infections are likely needed to improve long-term child growth outcomes.

The objective of this study was to assess the impact of different strategies for delivering supplemental zinc on fecal myeloperoxidase (MPO), neopterin (NEO), and calprotectin (CAL) among young Laotian children. In a double-blind controlled trial, children aged 6–23 months were randomized to receive either daily preventive zinc (PZ) tablets (7 mg/day), daily micronutrient powder (MNP; containing 10 mg zinc and 14 other micronutrients), therapeutic zinc (TZ) supplements for diarrhea treatment (20 mg/day for 10 days), or daily placebo powder and followed for ∼36 weeks. Stool samples were collected at baseline and endline. Fecal MPO, NEO, and CAL concentrations were determined in a randomly selected subsample of 720 children using commercially available ELISA kits. At baseline, the mean age was 14.1 ± 4.9 months and prevalence of stunting was 39%. The endline prevalence of stunting was 43%; there was no overall treatment effect on physical growth in the parent trial. At endline, the mean (95% CI) MPO in the PZ group was 1,590 [1,396; 1,811] ng/mL and did not differ from that in the MNP (1,633 [1,434; 1,859] ng/mL), TZ (1,749 [1,535; 1,992] ng/mL), and control (1,612 [1,415; 1,836] ng/mL) groups (P = 0.749). Similarly, there was no overall treatment effect on NEO and CAL concentrations (P = 0.226 and 0.229, respectively). In this population, the provision of PZ or TZ supplements or MNP had no impact on growth or environmental enteric dysfunction (EED) as assessed by fecal MPO, NEO, and CAL. Additional research is needed to better understand the etiology and proposed mechanisms of EED pathogenesis.