The American Journal of Tropical Medicine and Hygiene - Online First

Children in the Peruvian Amazon Basin are at risk of soil-transmitted helminths (STH) infections. This study aimed to determine the prevalence of STH infection in children from a rural Amazonian community of Peru and to elucidate epidemiological risk factors associated with its perpetuation while on a school-based deworming program with mebendazole. Stool samples of children aged 2–14 years and their mothers were analyzed through direct smear analysis, Kato–Katz, spontaneous sedimentation in tube, Baermann’s method, and agar plate culture. A questionnaire was administered to collect epidemiological information of interest. Among 124 children, 25.8% had one or more STH. Individual prevalence rates were as follows: Ascaris lumbricoides, 16.1%; Strongyloides stercoralis, 10.5%; hookworm, 1.6%; and Trichuris trichiura, (1.6%). The prevalence of common STH (A. lumbricoides, T. trichiura, and hookworm) was higher among children aged 2–5 years than older children (31.6% versus 12.8%; P = 0.01). In terms of sanitation deficits, walking barefoot was significantly associated with STH infection (OR = 3.28; CI 95% = 1.11–12.07). Furthermore, STH-infected children more frequently had a mother who was concomitantly infected by STH than the non-STH–infected counterpart (36.4% versus 14.1%, P = 0.02). In conclusion, STH infection is highly prevalent in children from this Amazonian community despite routine deworming. Institutional health policies may include hygiene and sanitation improvements and screening/deworming of mothers to limit the dissemination of STH. Further studies are needed to address the social and epidemiological mechanics perpetuating these infections.

Lower respiratory tract infections (LRTIs) are the leading cause of deaths in children < 5 years old worldwide, particularly affecting low-resource settings such as Aweil, South Sudan. In these settings, diagnosis can be difficult because of either lack of access to radiography or clinical algorithms that overtreat children with antibiotics who only have viral LRTIs. Point-of-care ultrasound (POCUS) has been applied to LRTIs, but not by nonphysician clinicians, and with limited data from low-resource settings. Our goal was to examine the feasibility of training the mid-level provider cadre clinical officers (COs) in a Médecins Sans Frontières project in South Sudan to perform a POCUS algorithm to differentiate among causes of LRTI. Six COs underwent POCUS training, and each subsequently performed 60 lung POCUS studies on hospitalized pediatric patients < 5 years old with criteria for pneumonia. Two blinded experts, with a tiebreaker expert adjudicating discordant results served as a reference standard to calculate test performance characteristics, assessed image quality and CO interpretation. The COs performed 360 studies. Reviewers rated 99.1% of the images acceptable and 86.0% CO interpretations appropriate. The inter-rater agreement (κ) between COs and experts for lung consolidation with air bronchograms was 0.73 (0.63–0.82) and for viral LRTI/bronchiolitis was 0.81 (0.74–0.87). It is feasible to train COs in South Sudan to use a POCUS algorithm to diagnose pneumonia and other pulmonary diseases in children < 5 years old.

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.

Long-lasting insecticide-treated bednets are widely used and promoted for malaria control. Limitations in measurement methods have resulted in a poor understanding of how bednets are used in practice. We deployed a novel remote monitoring tool in Uganda to obtain, for the first time, a comprehensive characterization of bednet use in households at risk for malaria. Ten households each used one SmartNet adherence monitor over a commonly used sleeping area for 6 weeks. SmartNet continuously measures and records bednet use every 15 minutes. Bednet use was monitored for a total of 9,258 hours overall, with an average of 42 nights per household (SD: 3.5). Average duration of bednet use was 9 hour 49 minutes per night (SD: 1 hour 56 minutes), and adherence was 85–90% from 2100 to 0600. Bednets were not used at all on 4.5% (19/418) of observation nights. Overall, the average clock time that bednets were unfurled was 2034 (SD: 1 hour 25 minutes) and they were folded up at 0743 (SD: 43 minutes). The rate of interruptions per night observed in all households was 0.23 (86/369), with an average duration of 48 minutes (SD: 49 minutes). There was substantial heterogeneity between households, and some households had consistently poorer adherence relative to others. Variations in bednet use behaviors are a potentially important, and under-researched, component of long-lasting insecticide-treated bednet effectiveness. Remote bednet use monitors can provide novel insights into how bednets are used in practice, helping identify both households at risk of malaria due to poor adherence and also potentially novel targets for improving malaria prevention.

Control of schistosomiasis presently relies largely on preventive chemotherapy with praziquantel through mass drug administration (MDA) programs. The Schistosomiasis Consortium for Operational Research and Evaluation has concluded five studies in four countries (Côte d’Ivoire, Kenya, Mozambique, and Tanzania) to evaluate alternative approaches to MDA. Studies involved four intervention years, with final evaluation in the fifth year. Mass drug administration given annually or twice over 4 years reduced average prevalence and intensity of schistosome infections, but not all villages that were treated in the same way responded similarly. There are multiple ways by which responsiveness to MDA, or the lack thereof, could be measured. In the analyses presented here, we defined persistent hot spots (PHSs) as villages that achieved less than 35% reduction in prevalence and/or less than 50% reduction in infection intensity after 4 years of either school-based or community-wide MDA, either annually or twice in 4 years. By this definition, at least 30% of villages in each of the five studies were PHSs. We found no consistent relationship between PHSs and the type or frequency of intervention, adequacy of reported MDA coverage, and prevalence or intensity of infection at baseline. New research is warranted to identify PHSs after just one or a few rounds of MDA, and new adaptive strategies need to be advanced and validated for turning PHSs into responder villages.

A previously healthy young man presented with a chronic cavitary pulmonary infection that began while in Goa, India. Burkholderia pseudomallei was cultured from sputum samples. The infection fully resolved after prolonged antibiotic treatment. Other than traveling during the monsoon season, extensive use of well-water for water-pipe smoking of cannabis was identified as a possible risk factor for infection. This is one of the first reports of travel-associated melioidosis from India. Genomic and immunological characterization suggested that the B. pseudomallei isolate collected from the reported case exhibited limited similarity to other B. pseudomallei strains.

Strongyloides stercoralis affects 30–100 million people worldwide. The burden is underestimated because of the paucity of studies, limited geographical areas surveyed, and poor quality of diagnostic tests. This study aimed at determining the epidemiology of strongyloidiasis using sensitive microscopy testing in rural populations living at different altitudes in Cusco, Peru. Data were collected from subjects aged > 3 years living in Quellouno (elevation 2,600 ft) and Limatambo (elevation 8,379 ft) districts. Subjects provided one fresh stool sample and answer a standardized questionnaire. Fresh stool was tested on site using the Baermann’s test and agar plate culture. Formalin-preserved stool was tested by rapid sedimentation. Eighty percent (585/715) of eligible subjects consented to participate; after excluding subjects with missing data, 65% (462/715) were included. Fifty-five percentage were female; the median age was 33 years (interquartile range 13–52), and 72% had government health insurance. Half had intestinal parasites, and strongyloides was the most common (24.5%) followed by Giardia spp. (15.5%), blastocystis (14.9%), and hookworm (11.5%). The agar plate culture detected more cases of Strongyloides than Baermann’s or sedimentation tests. Strongyloides infection was more common at low altitude (26.4%) than at high altitude (18.6%), but the difference was not statistically significant (P = 0.08). Older age, walking barefoot, bathing in rivers/streams, and using municipal sewage were associated with strongyloidiasis. Strongyloides was the most prevalent parasite in the areas studied and was associated with demographic, socioeconomic, and sanitary factors.

Statins have anti-inflammatory and immunomodulatory properties that may affect the development of tuberculosis (TB). We assessed the association between use of statins and the risk of active TB by propensity score matching. Furthermore, we analyzed the impact of statins on TB in patients according to the presence or absence of diabetes. The study was based on the National Health Insurance database and its subset database of the “medical checkup” population of South Korea. We identified 123,468 statin users and 439,546 non–statin users. After propensity score matching, 28,018 statin users and the same number of non–statin users were finally analyzed. The development of active TB was monitored in these matched pairs over 11 years. In the propensity score–matching analysis, the number of active TB cases was 30 in 30,303 person-years (0.99 per 1,000 person-years; 95% CI, 0.64–1.35) in the statin users and 235 in 167,857 person-years (1.40 per 1,000 person-years; 95% CI, 1.22–1.58) in the non–statin users. Statin users had a significantly lower risk of TB than non–statin users: hazard ratio (HR) 0.67 (95% CI, 0.46–0.98) (P = 0.04). A subgroup analysis showed that statin use reduced the risk of TB in subjects without diabetes, but not in patients with diabetes: HRs were, respectively, 0.28 (95% CI, 0.13–0.60) (P = 0.001) and 1.05 (95% CI, 0.66–1.67) (P = 0.84). There is epidemiologic evidence that statin decreases the risk of active TB. However, the protective effect of statins against TB is attenuated by diabetes.

Diarrheal disease is a leading cause of childhood morbidity and mortality worldwide, but particularly in low-income countries in sub-Saharan Africa and South Asia. The Global Enteric Multicenter Study (GEMS) examined the infectious etiologies as well as associated demographics, socioeconomic markers, health-care–seeking behaviors, and handwashing practices of the households of children with diarrhea and their age- and gender-matched controls in seven countries over a 3-year period (December 2007–December 2010). Stool studies to determine diarrheal etiologies and anthropometry were performed at baseline and at 60-day follow-up visits, along with surveys to record demographics and living conditions of the children. We performed secondary analyses of the GEMS data derived from the Bangladesh portion of the study in children with diarrhea associated with viral enteropathogens and explored pathogen-specific features of disease burden. Rotavirus and norovirus were the most prevalent pathogens (39.3% and 35%, respectively). Disease due to rotavirus and adenovirus was more common in infants than in older children (P < 0.001 and P = 0.001, respectively). Height for age decreased from baseline to follow-up in children with diarrhea associated with rotavirus, norovirus, and adenovirus (P < 0.001). Based on these analyses, preventive measures targeted at rotavirus, norovirus, and adenovirus will be expected to have meaningful clinical impact. Cost of treatment was highest for rotavirus as well, making it an obvious target for intervention. Association of specific viruses with stunting is particularly notable, as stunting is an attributable risk factor for poor cognitive development and future productivity and economic potential.

Melioidosis is a bacterial infection caused by exposure to water or soil that contains Burkholderia pseudomallei (Bp). Burkholderia pseudomallei is endemic to many tropical and subtropical areas of the world. In 2013, the first case of melioidosis was recognized in Yap, the Federated States of Micronesia. Six additional cases were identified in the subsequent 3 years. An investigation was initiated to understand the epidemiology of melioidosis in Yap. Serum from family and community members of the identified cases were tested for antibodies to Bp. Archived serum from a 2007 Zika serosurvey were also tested for antibodies to Bp. Sequencing of bacterial isolates was performed to understand bacterial phylogeny. Soil and water were tested for the presence of Bp in the environment by culture and PCR. None of the affected patients had a history of travel to melioidosis-endemic countries. Two of the 34 (5.8%) samples from the field investigation and 67 (11.7%) of the historical samples demonstrated serologic evidence of prior Bp exposure. No Bp were detected from 30 soil or water samples. Genotype analysis showed highly related Bp isolates that were unique to Yap. Melioidosis is likely to be endemic to Yap; however, it has only recently been recognized by the clinical community in country. Further investigation is needed to understand the local sites that harbor Bp and represent the highest risk to the community.