The American Journal of Tropical Medicine and Hygiene - Current Issue

Healthcare workforce shortages are continuing to increase worldwide with more profound deficits seen in rural communities in both developed and developing countries. These deficits impede progress towards heath equity and global health initiatives including the 2030 Sustainable Development Goals. Medical training has supported the idea that having a rural background influences future practice in rural settings. With a majority of global health experiences taking place in rural settings, there is an opportunity for health profession programs to take advantage of expanding global health education to encourage future practice in rural settings and address inequalities in workforce distribution.

Chagas disease remains a major impediment to sustainable socioeconomic development in Latin America. Transplacental transmission explains the persistence of transmission in urban areas, in non-endemic regions, and in areas with an established interrupted vectorial transmission. One of every five cases of congenital Chagas disease in the world occurs in Colombia and Venezuela. The massive migration of impoverished populations from neighboring Venezuela has worsened the situation creating a humanitarian crisis in Northeastern Colombia, including the Sierra Nevada de Santa Marta. The prevalence of Chagas infection among pregnant women in these areas is higher than the national average, and the public health resources are insufficient. This perspective discusses the associated increased morbidity and mortality of congenital Chagas in this region, where stigmatization contributes to the impression among health authorities and the general population that it affects indigenous communities only. The monitoring and control of congenital Chagas disease in the Sierra Nevada of Santa Marta is a public health necessity that demands urgent and effective interventions.

The neglected tropical diseases Zika, Ebola, and Lassa fever (LF) have all been noted to cause some degree of hearing loss (HL). Hearing loss is a chronic disability that can lead to a variety of detrimental effects, including speech and language delays in children, decreased economic productivity in adults, and accelerated cognitive decline in older adults. The objective of this review is to summarize what is known regarding HL secondary to these viruses. Literature for this review was gathered using the PubMed database. Articles were excluded if there were no data of the respective viruses, postinfectious complications, or conditions related to survivorship. A total of 50 articles were included in this review. Fourteen articles discussing Zika virus and subsequent complications were included. Across these studies, 56 (21.2%) of 264 Zika-infected individuals were found to have HL. Twenty-one articles discussing Ebola virus and subsequent complications were included, with 190 (5.7%) of 3,350 Ebola survivors found to have HL. Fifteen additional articles discussing LF and subsequent complications were included. Of 926 individuals with LF, 79 (8.5%) were found to have HL. These results demonstrate a relationship between HL and infection. The true prevalence is likely underestimated, however, because of lack of standardization of reporting and measurement. Future studies of viral sequelae would benefit from including audiometric evaluation. This information is critical to understanding pathophysiology, preventing future cases of this disability, and improving quality of life after survival of infection.

Buruli ulcer is an infectious disease provoking chronic, disabling skin ulcers in mammals and humans. Buruli ulcer is caused by Mycobacterium ulcerans, an environmental mycobacterium synthesizing a toxin called mycolactone responsible for the pathogenicity. The reservoirs and the modes of transmission of M. ulcerans remain elusive, limiting the prophylaxis capabilities in rural areas in endemic countries. In Australia, several studies have demonstrated the probable role of possums as reservoirs. In Côte d’Ivoire, some studies have speculated on the potential role of grasscutters in the transmission cycle of M. ulcerans. In this study, we detected M. ulcerans–specific sequences in rectal contents and spleens collected in wild grasscutters hunted in Buruli ulcer–endemic area in Côte d’Ivoire, but not in farmed negative control animals and in domesticated animals, namely, pigs, goats, cattle, and dogs, living in close contact with the local population. Some grasscutters exhibited the same sequence pattern in the feces and spleen. These observations confirm the asymptomatic gut carriage of M. ulcerans in this mammal species. Moreover, these observations suggest the dissemination of M. ulcerans from the gut to the spleen in grasscutters. These observations suggest that, in some mammals, M. ulcerans is not only an inoculated pathogen but also a translocating invasive pathogen.

We report a case of a 13-year-old immunocompetent male with multifocal tubercular osteomyelitis involving several spinal segments, small bones of the hands, and the scalp, who started with progressively back pain and enlarging painful swelling on the palms of hands, fatigue, and irregular fever. All the hand lesions were firm, mildly tender, and covered by ulcerated skin with serous discharge from the site. Magnetic resonance showed lesions of the right fifth metacarpal, of the right intermediate phalanx of the fourth finger, of the left second metacarpal, and of most vertebral bodies of the cervical, dorsal, lumbar, and sacral spine. The nucleic acid amplification test and the final culture from the drainage of the hands’ lesion were positive for Mycobacterium tuberculosis. The patient received a standard antitubercular treatment for 12 months with clinical improvement.

This article’s goal is to assess the perspectives of private providers on current and future public–private engagement in Metro Manila, a city of 13 million using semistructured interviews with a convenience sample of 18 private physicians. Our study found that private providers perceived their clientele as loyal and their services as distinct from public services, with unique attractions of convenience and quality of service. They saw value in engaging with the public sector for knowledge exchange, access to public-sector commodities, and access to public sector assistance with public health tasks related to tuberculosis (TB). However, their proposed ways of engaging were more centered on the private sector role, in ways that are not currently being pursued by the public sector. It is of the utmost importance to recognize that private provider perspectives are essential to build effective engagement models and, thus, to reach all clients with quality TB care.

Treatment for multidrug-resistant tuberculosis (MDR TB) is associated with adverse events (AE). Patients treated with an MDR TB regimen in Hospital Nossa Senhora da Paz, Cubal, Angola, were prospectively enrolled from May 2013 to July 2015. Baseline characteristics, AE, and clinical and microbiological outcomes were recorded. A total of 216 patients were treated with an MDR TB regimen and 179 (82.9%) patients developed at least one AE. The most common AE were elevation of liver enzymes (46.8% of patients), elevated creatinine (44.4% of patients), and ototoxicity (40.7% of patients). Previous TB treatment was associated with the occurrence of AE (OR 4.89, 95% CI: 2.09–11.46, P < 0.001) and months on treatment was associated to severe AE (OR 1.11 95% CI: 1.04–1.18, P = 0.001). Successful treatment was achieved in 117 (54.2%) patients. Incidence of AE was associated with an unsuccessful outcome (OR 1.23, 95% CI: 1.09–1.40, P = 0.001). Patients treated with MDR TB treatment frequently experience AE, and these are related with previous TB treatment and duration of treatment. Given the high percentage of patients experiencing AE and the low treatment success rates, more effective and less toxic drugs to treat MDR TB are urgently needed.

We aimed to investigate the epidemic situation of tuberculosis (TB) in prisons in the central region of China. Tuberculosis screening was carried out in two prisons in middle China. A sum of 3,459 prisoners accepted chest X-ray examination; 40 of them were diagnosed as active TB patients. The active TB prevalence (1,156/105) was significantly higher than that of the province and China’s general population (P < 0.01). As for gender, TB prevalence in men’s prison (1,589/105) was higher than that in the women’s prison (946/105). Nevertheless, the risk of having TB in women’s prison was much higher than that in the men’s prison when compared with the TB prevalence from the province (women: OR = 2.37, 95% CI: 1.34, 4.22; men: OR = 1.53, 95% CI: 0.90, 2.60) and the China’s general population (women: OR = 3.30, 95% CI: 2.15, 5.09; men: OR = 2.06, 95% CI: 1.29, 3.30). In view of the severe epidemic situation of TB in prisons, integrating medical resources to establish a consummate and effective management system is necessary.

Enteric fever is a major public health concern in endemic areas, particularly in infrastructure-limited countries where Salmonella Paratyphi A has emerged in increasing proportion of cases. We aimed to evaluate a method to detect Salmonella Typhi (S. Typhi) and Salmonella Paratyphi A (S. Paratyphi A) in febrile patients in Bangladesh. We conducted a prospective study enrolling patients with fever > 38°C admitted to two large urban hospitals and two outpatient clinics located in Dhaka, Bangladesh. We developed and evaluated a method combining short culture with a new molecular assay to simultaneously detect and differentiate S. Typhi and S. Paratyphi A from other Salmonella directly from 2 to 4 mL of whole blood in febrile patients (n = 680). A total of 680 cases were enrolled from the four participating sites. An increase in the detection rate (+38.8%) in S. Typhi and S. Paratyphi A was observed with a multiplex polymerase chain reaction (PCR) assay, and absence of non-typhoidal Salmonella detection was reported. All 45 healthy controls were culture and PCR negative, generating an estimated 92.9% of specificity on clinical samples. When clinical performance was assessed in the absence of blood volume prioritization for testing, a latent class model estimates clinical performance ≥ 95% in sensitivity and specificity with likelihood ratio (LR) LR+ > 10 and LR− < 0.1 for the multiplex PCR assay. The alternative method to blood culture we developed may be useful alone or in combination with culture or serological tests for epidemiological studies in high disease burden settings and should be considered as secondary endpoint test for future vaccine trials.

In 2017–18, a large-scale cholera outbreak swept Yemen. We calculated the number of culture-confirmed cases from the suspected cases and diagnosis testing records. We estimate 184,248 confirmed cholera cases between April 2017 and the end of 2017, and the reproduction number of 2.2 with 95% CI of [2.1, 2.3] during the initial stage. We find a significantly (nonlinear) positive association between the reproduction number (R t ) and precipitation, explained 13% of transmissibility changes, with one unit (mm) increment in precipitation leading to an increment of 20.1% in R t . We find a significantly (nonlinear) negative association between the R t and cumulative Google Trends index (GTI), explained 62% of transmissibility changes, with one unit increment in cumulative GTI leading to a drop of 0.03% in R t .

Subject to a high burden of diarrheal diseases, Afghanistan is also susceptible to climate change. This study investigated the spatiotemporal distribution of diarrheal disease in the country and how associated it is with climate variables. Using monthly aggregated new cases of acute diarrhea reported between 2010 and 2016 and monthly averaged climate data at the district level, we fitted a hierarchical Bayesian spatiotemporal statistical model. We found aridity and mean daily temperature were positively associated with diarrhea incidence; every 1°C increase in mean daily temperature and 0.01-unit change in the aridity index were associated with a 0.70% (CI: 0.67%, 0.73%) increase and a 4.79% (CI: 4.30%, 5.26%) increase in the risk of diarrhea, respectively. Average annual temperature, on the other hand, was negatively associated, with a 3.7% (CI: 3.74%, 3.68) decrease in risk for every degree Celsius increase in annual average temperature. Temporally, most districts exhibited similar seasonal trends, with incidence peaking in summer, except for the eastern region where differences in climate patterns and population density may be associated with high rates of diarrhea throughout the year. The results from this study highlight the significant role of climate in shaping diarrheal patterns in Afghanistan, allowing policymakers to account for potential impacts of climate change in their public health assessments.

Multiplex polymerase chain reaction (PCR) platforms have enhanced understanding of intestinal pathogens in low- and middle-income countries (LMICs). However, few such studies have been performed in Latin America, where poverty, poor sanitation, and undernutrition persist. Multiplex PCR (BioFire, Salt Lake City, UT) was used to identify viral, bacterial, and parasitic pathogens in stool collected on day 1 and 31 from children aged 6 to 35 months with acute, non-bloody diarrhea in two locations (rural and urban) in Guatemala. We analyzed correlation between pathogens and clinical, demographic, and socioeconomic variables; described patterns of pathogen acquisition, persistence, and clearance over the 30-day period; and calculated population attributable fractions (PAFs) for diarrheal causation for individual pathogens. We analyzed 316 subjects (144 urban; 172 rural) enrolled between March 2015 and January 2016. Rural subjects had significantly more malnutrition, animal exposure, and unimproved water/sanitation infrastructure. The majority of subjects had multiple pathogens/sample (4.8 rural and 2.7 urban). Few meaningful correlates were identified between individual pathogens and clinical, demographic, or environmental variables. Escherichia coli pathotypes, Shigella, Campylobacter, and Giardia had high rates of persistence between initial and 30-day follow-up. Statistically significant adjusted PAFs were identified for Campylobacter (14.9%, 95% CI: 3.2–23.1), norovirus (10.2%, 95% CI: 0.4–17.1), sapovirus (7.6%, 95% CI: 2.3–10.9), and adenovirus 40/41 (5.6%, 95% CI: 0.3–8.7). These observations further characterize the diversity and complexity of enteric pathogens in children in LMICs. Patterns of chronic symptomatic and asymptomatic infection among Latin American children are similar to those observed in other LMIC regions. Findings have direct implications for practitioners treating individuals with acute infectious diarrhea and should inform regional public health strategies.

Campylobacter jejuni is the leading bacterial cause of diarrhea worldwide. A capsular polysaccharide (CPS) conjugate vaccine is under development and requires determination of the valency. However, distribution of CPS types circulating globally is presently poorly described. We aimed to determine whether CPS type distribution in Peru differs from that in other endemic regions. We used a multiplex polymerase chain reaction (PCR) assay for the detection of CPS encoding genes capable of distinguishing all 35 CPS types on Campylobacter isolates in two prospective communities based studies conducted in cohorts of children less than 59 months of age in Peru. Results showed that CPS type HS4 complex was the most prevalent, followed by HS3 complex and HS15. Differences in CPS type for symptomatology were not statistically significant. Most subjects demonstrated repeated infections over time with different CPS types, suggesting that CPS types may confer of a level of homologous protective immunity. In this dataset, some differences in CPS type distribution were observed in comparison to other low-middle income countries. Further studies need to be conducted in endemic areas to increase our knowledge of CPS type distribution and guide vaccine development.

Infectious diarrhea cases have increased during the past years in the Anhui Province of China, but little is known about its spatial cluster pattern and associated socioeconomic factors. We obtained county-level total cases of infectious diarrhea in 105 counties of Anhui in 2016 and computed age-adjusted rates. Socioeconomic factors were collected from the Statistical Yearbook. Hot spot analysis was used to identify hot and cold spot counties for infectious diarrhea incidence. We then applied binary logistic regression models to determine the association between socioeconomic factors and hot spot or cold spot clustering risk. Hot spot analysis indicated there were both significant hot spot (29 counties) and cold spot (18 counties) clustering areas for infectious diarrhea in Anhui (P < 0.10). Multivariate binary logistic regression results showed that infectious diarrhea hot spots were positively associated with per capita gross domestic product (GDP), with an adjusted odds ratio (AOR): 3.51, 95% CI: 2.09–5.91, whereas cold spots clustering were positively associated with the number of medical staffs (AOR: 1.18, 95% CI: 1.08–1.29) and negatively associated with the number of public health physicians (AOR: 0.27, 95% CI: 0.09–0.86). We identified locations for hot and cold spot clusters of infectious diarrhea incidence in Anhui, and the clustering risks were significantly associated with health workforce resources and the regional economic development. Targeted interventions should be carried out with considerations of regional socioeconomic conditions.

Improving access to safe and affordable sanitation facilities is a global health priority that is essential for meeting the United Nation’s Sustainable Development Goals. To promote the use of improved sanitation in rural and low-income settings, plastic latrine slabs provide a simple option for upgrading traditional pit latrines. The International Finance Corporation/World Bank Selling Sanitation program estimated that plastic slabs would have a 34% annual growth, with a market size of US$2.53 million in Kenya by 2017. In this study, we examined the commercial viability of these plastic latrine slabs in rural Kenya by evaluating a financing and distribution model intervention, documenting household slab sales to date, and assessing consumer exposure and perceptions. We also determined household willingness to pay through a real-money auction with 322 households. We found that no households in our study area had purchased the plastic slabs. The primary barriers to slab sales were limited marketing activities and low demand compared with the sales price: households were willing to pay an average of US$5 compared with a market price of US$16. Therefore, current household demand for the plastic latrine slabs in rural Kenya is too low to support commercial distribution. Further efforts are required to align the price of plastic latrine slabs with consumer demand in this setting, such as additional demand creation, product financing, and public sector investment.

Poor hand hygiene and food handling put consumers of restaurant and street food at risk of enteric disease, especially in low-income countries. This study aimed to collect hygiene indicators from a nationally representative sample of restaurants and street food vendors. The field team collected data from 50 rural villages and 50 urban administrative units (mahallas). We explored restaurant service staff, cook, and food vendor hygiene practices (N = 300 restaurants and 600 street food vendors), by observing hygiene facilities, food handling, and utensil cleaning. A qualitative assessment explored perceptions of hygiene related to food handling. During restaurant spot checks, 91% (273/300) had soap and water at handwashing location for customers but in only 33% (100) at locations convenient for restaurant staff. Among street food–vending stalls, 11% (68/600) had soap and water when observed. During 90-minute structured observations, cooks used soap to wash hands on 14/514 (3%) of occasions before food preparation, 6/82 (8%) occasions after cutting fish/meat/vegetables, 3/71 (4%) occasions before serving food, and 0/49 (0%) occasions) before hand-mashing food/salad preparation; no street food vendors washed hands with soap during these food-handling events. Most of the qualitative study participants perceived that customers select a vendor based on tastiness of the food, whereas no one mentioned the importance of food hygiene. The study demonstrates widespread poor hygiene and food-handling practices in restaurants and among food vendors. Based on our study findings, we proposed a food premises Hygiene Investigation Model to create action plans to improve food safety.

To address water and hygiene infrastructure deficiencies in health-care facilities (HCFs) in Siaya County, Kenya, portable water stations, soap, and water treatment products were provided to 109 HCFs in 2005. In 2011 and again in 2016, we interviewed staff in 26 randomly selected HCFs, observed water sources, water stations, and tested source and stored water for chlorine residual and Escherichia coli. Of 26 HCFs, 22 (85%) had improved water supplies, and 22 (85%) had functioning handwashing and drinking water stations, but < 50% provided soap or water treatment. Thirteen (50%) of 26 source water samples yielded E. coli; 24 (92%) of 26 stored water samples yielded no E. coli, including nine with residual chlorine and nine untreated samples from sources yielding no E. coli. Eleven years after implementation, 85% of HCFs continued to use water stations that protected water from recontamination. Sustainable provision of soap and water treatment products could optimize intervention use.