The American Journal of Tropical Medicine and Hygiene - Current Issue

We calculated carbon emissions associated with air travel of 4,834 participants at the 2019 annual conference of the American Society of Tropical Medicine and Hygiene (ASTMH). Together, participants traveled a total of 27.7 million miles or 44.6 million kilometers. This equates to 58 return trips to the moon. Estimated carbon dioxide equivalent (CO2e) emissions were 8,646 metric tons or the total weekly carbon footprint of approximately 9,366 average American households. These emissions contribute to climate change and thus may exacerbate many of the global diseases that conference attendees seek to combat. Options to reduce conference travel–associated emissions include 1) alternating in-person and online conferences, 2) offering a hybrid in-person/online conference, and 3) decentralizing the conference with multiple conference venues. Decentralized ASTMH conferences may allow for up to 64% reduction in travel distance and 58% reduction in CO2e emissions. Given the urgency of the climate crisis and the clear association between global warming and global health, ways to reduce carbon emissions should be considered.

The highly infectious nature of the SARS-CoV-2 virus requires rigorous infection prevention and control (IPC) to reduce the transmission of COVID-19 within healthcare facilities, but in low-resource settings, the lack of water access creates a perfect storm for low-handwashing adherence, ineffective surface decontamination, and other environmental cleaning functions that are critical for IPC compliance. Data from the WHO/UNICEF Joint Monitoring Programme show that one in four healthcare facilities globally lacks a functional water source on premises (i.e., basic water service); in sub-Saharan Africa, half of all healthcare facilities have no basic water services. But even these data do not tell the whole story, other water, sanitation, and hygiene (WASH) assessments in low-resource healthcare facilities have shown the detrimental effects of seasonal or temporary water shortages, nonfunctional water infrastructure, and fluctuating water quality. The rapid spread of COVID-19 forces us to reexamine prevailing norms within national health systems around the importance of WASH for quality of health care, the prioritization of WASH in healthcare facility investments, and the need for focused, cross-sector leadership and collaboration between WASH and health professionals. What COVID-19 reveals about infection prevention in low-resource healthcare facilities is that we can no longer afford to “work around” WASH deficiencies. Basic WASH services are a fundamental prerequisite to compliance with the principles of IPC that are necessary to protect patients and healthcare workers in every setting.

Effective management of a pandemic due to a respiratory virus requires public health capacity for a coordinated response for mandatory restrictions, large-scale testing to identify infected individuals, capacity to isolate infected cases and track and test contacts, and health services for those infected who require hospitalization. Because of contextual and socioeconomic factors, it has been hard for Latin America to confront this epidemic. In this article, we discuss the context and the initial responses of eight selected Latin American countries, including similarities and differences in public health, economic, and fiscal measures, and provide reflections on what worked and what did not work and what to expect moving forward.

The Peruvian Ministry of Health reports a near absence of malaria cases in the Amazon region during the COVID-19 pandemic. However, the rapid increase in SARS-CoV-2 infections has overwhelmed the Peruvian health system, leading to national panic and closure of public medical facilities, casting doubt on how accurately malaria cases’ numbers reflect reality. In the Amazon region of Loreto, where malaria cases are concentrated, COVID-19 has led to near-complete closure of the primary healthcare system, and diagnosis and treatment of acute febrile illnesses, including malaria, has plummeted. Here, we describe the potential association of COVID-19 with a markedly reduced number of reported malaria cases due to the reduced control activities carried out by the Peruvian Malaria Zero Program, which could lead to malaria resurgence and an excess of morbidity and mortality.

The effects of COVID-19 have gone undocumented in nomadic pastoralist communities across Africa, which are largely invisible to health surveillance systems despite the fact that they are of key significance in the setting of emerging infectious disease. We expose these landscapes as a “blind spot” in global health surveillance, elaborate on the ways in which current health surveillance infrastructure is ill-equipped to capture pastoralist populations and the animals with which they coexist, and highlight the consequential risks of inadequate surveillance among pastoralists and their livestock to global health. As a platform for further dialogue, we present concrete solutions to address this gap.

COVID-19 is a global health emergency facing many countries around the world. Sex workers in Africa are among one of the vulnerable populations disproportionately affected by the COVID-19 pandemic on the continent. Sex workers are excluded from African government safety net, and this may force some sex workers back to sex work amid the COVID-19 pandemic. Because of the nature of sex work, physical distancing and other precautionary measures are impossible to observe, further compromising COVID-19 response. Sex workers in Africa have been known to face high levels of stigma and discrimination, including limited access to healthcare services. Disruption in HIV care and prevention services due to the pandemic among this key population may have negative impacts on the hard-won achievements in HIV response in Africa. In addition, stigma and discrimination toward sex workers could also make contact tracing challenging and limit access to COVID-19 testing among this vulnerable group. With the adoption of the 2030 Agenda for the UN Development Program, UN member states all pledged to ensure “no one will be left behind” and to “endeavor to reach the furthest behind first.” This could not be more important than now as sex workers as a part of the population are left behind in COVID-19 response in Africa. It is important that the African government should ensure collective and inclusive response in the fight against COVID-19. Sex workers should not be forgotten in Africa’s COVID-19 response because no one is safe, until all are safe.

COVID-19 manifestations in symptomatic patients can be in the form of pneumonia, acute respiratory syndrome, and multiple organ dysfunction as well. Renal complications, gastrointestinal dysfunctions, endocrine system disorders, myocardial dysfunction and arrhythmia, neurological dysfunctions, dermatological symptoms, hematological manifestations, and thromboinflammation are among the reported extrapulmonary complications. Moreover, the presence of coagulopathy, excessive and dysregulated immune responses, and autoimmunity by COVID-19 patients is considerable. The pathogenesis of infection entails the entry of the virus via receptors on cells, principally angiotensin-converting enzyme 2 receptors. Direct virus damage coupled with indirect effects of viral infection including thromboinflammation, dysfunction of the immune system, and dysregulation of the renin–angiotensin system leads to multiple organ failure. This review outlines the extrapulmonary organ–specific complications and their pathophysiology and epidemiology.

In low- and middle-income countries, in resource-limited settings, the implementation of diagnostic tools discriminating bacterial from nonbacterial fever is a matter of primary concern. The introduction of malaria rapid diagnostic tests highlighted the need for point-of-care tests (POCTs) supporting clinical decision-making for non-malarial febrile illnesses. The purpose of this work was to review the use of host biomarker POCTs for the assessment of acute non-malarial fever in resource-constraint settings. Specific objectives were as follows: 1) to estimate the accuracy of such tests in differentiating fever of bacterial from nonbacterial origin and 2) to assess the impact of host biomarkers on antibiotic prescription and clinical outcome. We conducted a systematic review searching PubMed, Embase, the Cochrane Library, and Bireme. The protocol was registered with PROSPERO (n CRD42019141735). Data on the accuracy of C-reactive protein (CRP) for the detection of bacterial infections were meta-analyzed using the hierarchical summary receiver operating characteristic model, obtaining a summary ROC (SROC). We identified 2,192 articles, eight of which were included in the review. Among the different biomarkers evaluated, CRP was the one most frequently studied. The SROC presented an area under the curve = 0.77 (CI: 0.73–0.81), which indicates good accuracy to distinguish bacterial from nonbacterial infections. However, the optimal cutoff of CRP could not be assessed, and we found insufficient evidence about its impact on antibiotic prescription and clinical outcome. The role of CRP and other host biomarker POCTs for the assessment of acute non-malarial febrile illnesses in resource-constraint settings deserves further studies.

The use of antimicrobial growth promoters in chicken farming has been commonly associated with high levels of antimicrobial resistance (AMR) in humans. Most of this work, however, has been focused on intensive large-scale operations. Intensive small-scale farming that regularly uses antibiotics is increasing worldwide and has different exposure pathways compared with large-scale farming, most notably the spatial connection between chickens and households. In these communities, free-ranging backyard chickens (not fed antibiotics) can roam freely, whereas broiler chickens (fed antibiotics) are reared in the same husbandry environment but confined to coops. We conducted an observational field study to better understand the spatial distribution of AMR in communities that conduct small-scale farming in northwestern Ecuador. We analyzed phenotypic resistance of Escherichia coli sampled from humans and backyard chickens to 12 antibiotics in relation to the distance to the nearest small-scale farming operation within their community. We did not find a statistically significant relationship between the distance of a household to small-scale farming and antibiotic-resistant E. coli isolated from chicken or human samples. To help explain this result, we monitored the movement of backyard chickens and found they were on average 17 m (min–max: 0–59 m) from their household at any given time. These backyard chickens on average ranged further than the average distance from any study household to its closest neighbor. This level of connectivity provides a viable mechanism for the spread of antimicrobial-resistant bacteria and genes throughout the community.

Persons from the Republic of the Marshall Islands have among the highest rates of Hansen’s disease (HD) in the world; the largest Marshallese community in the continental United States is in northwest Arkansas. In 2017, the HD Ambulatory Care Clinic in Springdale, Arkansas, informed the Arkansas Department of Health (ADH) that Marshallese persons with HD had severe disease with frequent complications. To characterize their illness, we reviewed ADH surveillance reports of HD among Marshallese persons in Arkansas treated during 2003–2017 (n = 42). Hansen’s Disease prevalence among Marshallese in Arkansas (11.7/10,000) was greater than that in the general U.S. population. Complications included arthritis (38%), erythema nodosum leprosum (21%), and prolonged treatment lasting > 2 years (40%). The majority (82%) of patients treated for > 2 years had documented intermittent therapy. Culturally appropriate support for therapy and adherence is needed in Arkansas.

This study in the Amhara and Oromia regions of Ethiopia assessed the outcomes of tuberculosis (TB) treatment among children younger than 15 years. Retrospective data were collected on treatment outcomes and their determinants for children with TB for the cohorts of 2012–2014 enrolled in 40 hospitals and 137 health centers. Chi-square tests, t-tests, and logistic regression were used for the analysis. Of 2,557 children registered, 1,218 (47.6%) had clinically diagnosed pulmonary TB, 1,100 (43%) had extrapulmonary TB, and 277 (8.9%) had bacteriologically confirmed TB. Among all cases, 2,503 (97.9%) were newly diagnosed and 178 (7%) were HIV positive. Two-thirds of the children received directly observed treatment (DOT) in health centers and the remaining one-third, in hospitals. The treatment success rate (TSR) was 92.2%, and the death rate was 2.8%. The childhood TSR was high compared with those reported in focal studies in Ethiopia, but no national TSR report for children exists for comparison. Multivariate analysis showed that being older—5–9 years (adjusted odds ratio [AOR], 95% CI: 2.53, 1.30–4.94) and 10–14 years (AOR, 95% CI: 2.71, 1.40–5.26)—enrolled in DOT in a health center (AOR, 95% CI: 2.51, 1.82–3.48), and HIV negative (AOR, 95% CI: 1.77, 1.07–2.93) were predictors of treatment success, whereas underdosing during the intensive phase of treatment (AOR, 95% CI: 0.54, 0.36–0.82) was negatively correlated with treatment success. We recommend more research to determine if intensive monitoring of children with TB, dosage adjustment of anti-TB drugs based on weight changes, and training of health workers on dosage adjustment might improve treatment outcomes.

Identifying children with, or at substantial risk of, Mycobacterium tuberculosis infection (TBI) and providing TB preventive therapy (TPT) represent an important, yet challenging, strategy in curbing the global burden of childhood TB. Risk assessment scoring tools, which quantify risks associated with unique factors characterizing an individual, could act as a surrogate measure of TBI risk and guide effective and efficient TPT delivery. We assessed important risk factors of childhood TBI and created risk assessment tools through secondary analysis of data from a large, community-based childhood TB prevalence study in the island province of Bohol in the Philippines, a low–HIV- and high–TB-burden, post-disaster setting. We identified four factors that were statistically associated with acquiring TBI—being 5 years or older, having a known TB contact, having a known TB contact who was either the mother or another primary caregiver, and living in a high–TB-burden municipality. We created 2-item, 4-item, and 9-item scores intended to identify child TBI in this low-resource, low–HIV-, and high–TB-burden setting. In addition to the design, evaluation, and impact analysis of these generalizable and valuable risk assessment tools, our study findings emphasize the necessity of targeting both household and community-associated transmissions of childhood TBI to achieve the global goal to end TB.

Lung ultrasound (LUS) is highly portable and has excellent diagnostic accuracy for pneumonia compared with conventional radiography, but the literature on its use in pulmonary tuberculosis (PTB) is limited. This study characterized LUS lesions in patients with PTB and compared them with chest X-ray (CXR) findings. Adult patients in Lima, Peru, with PTB were recruited within 1 week of starting antituberculosis treatment. Comprehensive LUS was performed in all patients at enrollment and assessed for consolidation, small subpleural consolidation (SPC, hypothesized to be a marker of CXR consolidation), cavity, pleural effusion, pathologic B-lines, and miliary pattern. Patient CXRs were digitized and interpreted by a board-certified radiologist. Fifty-one patients were included in the final analysis. Lung ultrasound detected either consolidation or SPC in 96.1% of participants. No significant difference was found between the LUS detection of a composite of consolidation or SPC, and CXR detection of consolidation (96.1% versus 98%, P > 0.99). The proportion of patients with cavity detected by LUS was significantly lower than that detected by CXR (5.9% versus 51%, P < 0.001). Overall, LUS detection of consolidation or SPC may be a sensitive marker for diagnosis of PTB. Lung ultrasound demonstrated poor ability to detect radiographically identified cavity, although previous studies suggest SPC could add specificity for the diagnosis of PTB. Based on its portability and evidence base for diagnosing other pulmonary diseases, LUS may have a role in screening and diagnosis of PTB in areas without ready access to CXR. Further studies should evaluate its diagnostic accuracy in patients with and without PTB.

Leptospira spp. are fastidious and slow-growing bacteria, making recovery difficult and diagnostic sensitivity in the clinical setting low. However, collection of Leptospira isolates is valuable for epidemiological and laboratory research. Severe leptospirosis cases may present as septic shock, and the differential diagnosis often includes bacterial septicemia, leading clinicians to collect blood cultures. Here, we report the successful isolation of pathogenic Leptospira spp. from blood culture bottles (targeting aerobic bacteria incubated at 37°C) from a 64-year-old man admitted with septic shock. The patient presented with 4 days of fever, severe hypotension, transient atrial fibrillation, jaundice, and oliguric renal failure. After admission, intravenous ceftriaxone plus azithromycin was given with fluid resuscitation, norepinephrine infusion, invasive mechanical ventilation, and renal replacement therapy. He was discharged from the hospital 16 days after admission. Using the blood sample obtained on admission, the diagnosis of leptospirosis was confirmed by multiplex real-time PCR (targeting bacterial 16S rRNA and LipL32 gene). We collected 200 μL from the blood culture bottle to inoculate a 5-mL Ellinghausen, McCullough, Johnson, and Harris media supplemented with 5% fetal bovine serum. After 2 weeks of incubation at 30°C, Leptospira strains were identified and confirmed by real-time PCR. Genotyping was undertaken using the multi-locus sequence typing (MLST) scheme#1. The isolate matched with ST50 isolates in the PUbMLST database. This case provides evidence that in tropical countries, severe leptospirosis should be considered in patients who present with symptoms of sepsis. Pathogenic Leptospira may be successfully isolated from aerobic blood cultures in routine clinical settings.

Burkholderia pseudomallei is an emerging pathogen in the Americas. Cases of mother-to-child transmission of B. pseudomallei are rare and probably occur by placental or perinatal infection. We report the first case of native gestational and neonatal melioidosis in the Western hemisphere. The isolated strains in the mother and newborn were confirmed by whole-genome sequencing and identified as a novel sequence type ST1748. The comparison of both genomes revealed a nucleotide similarity of 100%. Melioidosis should be considered within the differential diagnosis of febrile illness or pneumonia in pregnant women and newborns from endemic areas of the Americas.