Drivers of Decline in Diarrhea Mortality Between GEMS and VIDA Studies.

BACKGROUND: Statistical modeling suggests that decreasing diarrhea-associated mortality rates in recent decades are largely attributed to improved case management, rotavirus vaccine, and economic development. METHODS: We examined data collected in 2 multisite population-based diarrhea case-control studies, both conducted in The Gambia, Kenya, and Mali: the Global Enteric Multicenter Study (GEMS; 2008-2011) and Vaccine Impact on Diarrhea in Africa (VIDA; 2015-2018). Population-level diarrhea mortality and risk factor prevalence, estimated using these study data, were used to calculate the attribution of risk factors and interventions for diarrhea mortality using a counterfactual framework. We performed a decomposition of the effects of the changes in exposure to each risk factor between GEMS and VIDA on diarrhea mortality for each site. RESULTS: Diarrhea mortality among children under 5 in our African sites decreased by 65.3% (95% confidence interval [CI]: -80.0%, -45.0%) from GEMS to VIDA. Kenya and Mali had large relative declines in diarrhea mortality between the 2 periods with 85.9% (95% CI: -95.1%, -71.5%) and 78.0% (95% CI: -96.0%, 36.3%) reductions, respectively. Among the risk factors considered, the largest declines in diarrhea mortality between the 2 study periods were attributed to reduction in childhood wasting (27.2%; 95% CI: -39.3%, -16.8%) and an increased rotavirus vaccine coverage (23.1%; 95% CI: -28.4%, -19.4%), zinc for diarrhea treatment (12.1%; 95% CI: -16.0%, -8.9%), and oral rehydration salts (ORS) for diarrhea treatment (10.2%). CONCLUSIONS: The VIDA study sites demonstrated exceptional reduction in diarrhea mortality over the last decade. Site-specific differences highlight an opportunity for implementation science in collaboration with policymakers to improve the equitable coverage of these interventions globally.

Hospital-based surveillance for Japanese encephalitis in Bangladesh, 2007-2016: Implications for introduction of immunization.

BACKGROUND: Japanese encephalitis (JE) virus is recognized as a major cause of encephalitis in Bangladesh. The World Health Organization (WHO) recommends human immunization as the most effective means to control JE. Several WHO-prequalified vaccines are available to prevent JE but no vaccination program has been implemented in Bangladesh. METHODS: We conducted hospital-based surveillance for acute meningitis-encephalitis syndrome (AMES) to describe JE epidemiology and help inform policy decisions about possible immunization strategies for Bangladesh. RESULTS: During 2007-2016, a total of 6543 AMES patients were identified at four tertiary hospitals. Of the 6525 patients tested, 548 (8%) were classified as JE cases. These 548 patients resided in 36 (56%) out of 64 districts of Bangladesh, with the highest proportion of JE cases among AMES patients (12% and 7%) presenting at two hospitals in the northwestern part of the country. The median age of JE cases was 30 years, and 193 (35%) were aged ≤15 years. The majority of JE cases (80%) were identified from July through November. CONCLUSIONS: Surveillance results suggest that JE continues to be an important cause of meningo-encephalitis in Bangladesh. Immunization strategies including JE vaccine introduction into the routine childhood immunization program or mass vaccination in certain age groups or geographic areas need to be examined, taking into consideration the cost-effectiveness ratio of the approach and potential for decreasing disease burden.

Diarrhoeal disease and subsequent risk of death in infants and children residing in low-income and middle-income countries: analysis of the GEMS case-control study and 12-month GEMS-1A follow-on study.

BACKGROUND: The Global Enteric Multicenter Study (GEMS) was a 3-year case-control study that measured the burden, aetiology, and consequences of moderate-to-severe diarrhoea (MSD) in children aged 0-59 months. GEMS-1A, a 12-month follow-on study, comprised two parallel case-control studies, one assessing MSD and the other less-severe diarrhoea (LSD). In this report, we analyse the risk of death with each diarrhoea type and the specific pathogens associated with fatal outcomes. METHODS: GEMS was a prospective, age-stratified, matched case-control study done at seven sites in Africa and Asia. Children aged 0-59 months with MSD seeking care at sentinel health centres were recruited along with one to three randomly selected matched community control children without diarrhoea. In the 12-month GEMS-1A follow-on study, children with LSD and matched controls, in addition to children with MSD and matched controls, were recruited at six of the seven sites; only cases of MSD and controls were enrolled at the seventh site. We compared risk of death during the period between enrolment and one follow-up household visit done about 60 days later (range 50-90 days) in children with MSD and LSD and in their respective controls. Approximately 50 pathogens were detected using, as appropriate, classic bacteriology, immunoassays, gel-based PCR and reverse transcriptase PCR, and quantitative real-time PCR (qPCR). Specimens from a subset of GEMS cases and controls were also tested by a TaqMan Array Card that compartmentalised probe-based qPCR for 32 enteropathogens. FINDINGS: 223 (2·0%) of 11 108 children with MSD and 43 (0·3%) of 16 369 matched controls died between study enrolment and the follow-up visit at about 60 days (hazard ratio [HR] 8·16, 95% CI 5·69-11·68, p<0·0001). 12 (0·4%) of 2962 children with LSD and seven (0·2%) of 4074 matched controls died during the follow-up period (HR 2·78, 95% CI 0·95-8·11, p=0·061). Risk of death was lower in children with dysenteric MSD than in children with non-dysenteric MSD (HR 0·20, 95% CI 0·05-0·87, p=0·032), and lower in children with LSD than in those with non-dysenteric MSD (HR 0·29, 0·14-0·59, p=0·0006). In children younger than 24 months with MSD, infection with typical enteropathogenic Escherichia coli, enterotoxigenic E coli encoding heat-stable toxin, enteroaggregative E coli, Shigella spp (non-dysentery cases), Aeromonas spp, Cryptosporidium spp, and Entamoeba histolytica increased risk of death. Of 61 deaths in children aged 12-59 months with non-dysenteric MSD, 31 occurred among 942 children qPCR-positive for Shigella spp and 30 deaths occurred in 1384 qPCR-negative children (HR 2·2, 95% CI 1·2-3·9, p=0·0090), showing that Shigella was strongly associated with increased risk of death. INTERPRETATION: Risk of death is increased following MSD and, to a lesser extent, LSD. Considering there are approximately three times more cases of LSD than MSD in the population, more deaths are expected among children with LSD than in those with MSD. Because the major attributable LSD-associated and MSD-associated pathogens are the same, implementing vaccines and rapid diagnosis and treatment interventions against these major pathogens are rational investments. FUNDING: Bill & Melinda Gates Foundation.

Use of quantitative molecular diagnostic methods to identify causes of diarrhoea in children: a reanalysis of the GEMS case-control study.

BACKGROUND: Diarrhoea is the second leading cause of mortality in children worldwide, but establishing the cause can be complicated by diverse diagnostic approaches and varying test characteristics. We used quantitative molecular diagnostic methods to reassess causes of diarrhoea in the Global Enteric Multicenter Study (GEMS). METHODS: GEMS was a study of moderate to severe diarrhoea in children younger than 5 years in Africa and Asia. We used quantitative real-time PCR (qPCR) to test for 32 enteropathogens in stool samples from cases and matched asymptomatic controls from GEMS, and compared pathogen-specific attributable incidences with those found with the original GEMS microbiological methods, including culture, EIA, and reverse-transcriptase PCR. We calculated revised pathogen-specific burdens of disease and assessed causes in individual children. FINDINGS: We analysed 5304 sample pairs. For most pathogens, incidence was greater with qPCR than with the original methods, particularly for adenovirus 40/41 (around five times), Shigella spp or enteroinvasive Escherichia coli (EIEC) and Campylobactor jejuni o C coli (around two times), and heat-stable enterotoxin-producing E coli ([ST-ETEC] around 1·5 times). The six most attributable pathogens became, in descending order, Shigella spp, rotavirus, adenovirus 40/41, ST-ETEC, Cryptosporidium spp, and Campylobacter spp. Pathogen-attributable diarrhoeal burden was 89·3% (95% CI 83·2-96·0) at the population level, compared with 51·5% (48·0-55·0) in the original GEMS analysis. The top six pathogens accounted for 77·8% (74·6-80·9) of all attributable diarrhoea. With use of model-derived quantitative cutoffs to assess individual diarrhoeal cases, 2254 (42·5%) of 5304 cases had one diarrhoea-associated pathogen detected and 2063 (38·9%) had two or more, with Shigella spp and rotavirus being the pathogens most strongly associated with diarrhoea in children with mixed infections. INTERPRETATION: A quantitative molecular diagnostic approach improved population-level and case-level characterisation of the causes of diarrhoea and indicated a high burden of disease associated with six pathogens, for which targeted treatment should be prioritised. FUNDING: Bill & Melinda Gates Foundation.

The Burden of Cryptosporidium Diarrheal Disease among Children < 24 Months of Age in Moderate/High Mortality Regions of Sub-Saharan Africa and South Asia, Utilizing Data from the Global Enteric Multicenter Study (GEMS).

BACKGROUND: The importance of Cryptosporidium as a pediatric enteropathogen in developing countries is recognized. METHODS: Data from the Global Enteric Multicenter Study (GEMS), a 3-year, 7-site, case-control study of moderate-to-severe diarrhea (MSD) and GEMS-1A (1-year study of MSD and less-severe diarrhea [LSD]) were analyzed. Stools from 12,110 MSD and 3,174 LSD cases among children aged <60 months and from 21,527 randomly-selected controls matched by age, sex and community were immunoassay-tested for Cryptosporidium. Species of a subset of Cryptosporidium-positive specimens were identified by PCR; GP60 sequencing identified anthroponotic C. parvum. Combined annual Cryptosporidium-attributable diarrhea incidences among children aged <24 months for African and Asian GEMS sites were extrapolated to sub-Saharan Africa and South Asian regions to estimate region-wide MSD and LSD burdens. Attributable and excess mortality due to Cryptosporidium diarrhea were estimated. FINDINGS: Cryptosporidium was significantly associated with MSD and LSD below age 24 months. Among Cryptosporidium-positive MSD cases, C. hominis was detected in 77.8% (95% CI, 73.0%-81.9%) and C. parvum in 9.9% (95% CI, 7.1%-13.6%); 92% of C. parvum tested were anthroponotic genotypes. Annual Cryptosporidium-attributable MSD incidence was 3.48 (95% CI, 2.27-4.67) and 3.18 (95% CI, 1.85-4.52) per 100 child-years in African and Asian infants, respectively, and 1.41 (95% CI, 0.73-2.08) and 1.36 (95% CI, 0.66-2.05) per 100 child-years in toddlers. Corresponding Cryptosporidium-attributable LSD incidences per 100 child-years were 2.52 (95% CI, 0.33-5.01) and 4.88 (95% CI, 0.82-8.92) in infants and 4.04 (95% CI, 0.56-7.51) and 4.71 (95% CI, 0.24-9.18) in toddlers. We estimate 2.9 and 4.7 million Cryptosporidium-attributable cases annually in children aged <24 months in the sub-Saharan Africa and India/Pakistan/Bangladesh/Nepal/Afghanistan regions, respectively, and ~202,000 Cryptosporidium-attributable deaths (regions combined). ~59,000 excess deaths occurred among Cryptosporidium-attributable diarrhea cases over expected if cases had been Cryptosporidium-negative. CONCLUSIONS: The enormous African/Asian Cryptosporidium disease burden warrants investments to develop vaccines, diagnostics and therapies.

Low-Cost National Media-Based Surveillance System for Public Health Events, Bangladesh.

We assessed a media-based public health surveillance system in Bangladesh during 2010-2011. The system is a highly effective, low-cost, locally appropriate, and sustainable outbreak detection tool that could be used in other low-income, resource-poor settings to meet the capacity for surveillance outlined in the International Health Regulations 2005.

Family caregivers in public tertiary care hospitals in Bangladesh: risks and opportunities for infection control.

BACKGROUND: Family caregivers are integral to patient care in Bangladeshi public hospitals. This study explored family caregivers' activities and their perceptions and practices related to disease transmission and prevention in public hospitals. METHODS: Trained qualitative researchers conducted a total of 48 hours of observation in 3 public tertiary care hospitals and 12 in-depth interviews with family caregivers. RESULTS: Family caregivers provided care 24 hours a day, including bedside nursing, cleaning care, and psychologic support. During observations, family members provided 2,065 episodes of care giving, 75% (1,544) of which involved close contact with patients. We observed family caregivers washing their hands with soap on only 4 occasions. The majority of respondents said diseases are transmitted through physical contact with surfaces and objects that have been contaminated with patient secretions and excretions, and avoiding contact with these contaminated objects would help prevent disease. CONCLUSION: Family caregivers are at risk for hospital-acquired infection from their repeated exposure to infectious agents combined with their inadequate hand hygiene and knowledge about disease transmission. Future research should explore potential strategies to improve family caregivers' knowledge about disease transmission and reduce family caregiver exposures, which may be accomplished by improving care provided by health care workers.

Burden and aetiology of diarrhoeal disease in infants and young children in developing countries (the Global Enteric Multicenter Study, GEMS): a prospective, case-control study.

BACKGROUND: Diarrhoeal diseases cause illness and death among children younger than 5 years in low-income countries. We designed the Global Enteric Multicenter Study (GEMS) to identify the aetiology and population-based burden of paediatric diarrhoeal disease in sub-Saharan Africa and south Asia. METHODS: The GEMS is a 3-year, prospective, age-stratified, matched case-control study of moderate-to-severe diarrhoea in children aged 0-59 months residing in censused populations at four sites in Africa and three in Asia. We recruited children with moderate-to-severe diarrhoea seeking care at health centres along with one to three randomly selected matched community control children without diarrhoea. From patients with moderate-to-severe diarrhoea and controls, we obtained clinical and epidemiological data, anthropometric measurements, and a faecal sample to identify enteropathogens at enrolment; one follow-up home visit was made about 60 days later to ascertain vital status, clinical outcome, and interval growth. FINDINGS: We enrolled 9439 children with moderate-to-severe diarrhoea and 13,129 control children without diarrhoea. By analysing adjusted population attributable fractions, most attributable cases of moderate-to-severe diarrhoea were due to four pathogens: rotavirus, Cryptosporidium, enterotoxigenic Escherichia coli producing heat-stable toxin (ST-ETEC; with or without co-expression of heat-labile enterotoxin), and Shigella. Other pathogens were important in selected sites (eg, Aeromonas, Vibrio cholerae O1, Campylobacter jejuni). Odds of dying during follow-up were 8·5-fold higher in patients with moderate-to-severe diarrhoea than in controls (odd ratio 8·5, 95% CI 5·8-12·5, p<0·0001); most deaths (167 [87·9%]) occurred during the first 2 years of life. Pathogens associated with increased risk of case death were ST-ETEC (hazard ratio [HR] 1·9; 0·99-3·5) and typical enteropathogenic E coli (HR 2·6; 1·6-4·1) in infants aged 0-11 months, and Cryptosporidium (HR 2·3; 1·3-4·3) in toddlers aged 12-23 months. INTERPRETATION: Interventions targeting five pathogens (rotavirus, Shigella, ST-ETEC, Cryptosporidium, typical enteropathogenic E coli) can substantially reduce the burden of moderate-to-severe diarrhoea. New methods and accelerated implementation of existing interventions (rotavirus vaccine and zinc) are needed to prevent disease and improve outcomes. FUNDING: The Bill & Melinda Gates Foundation.

Piloting the use of indigenous methods to prevent Nipah virus infection by interrupting bats' access to date palm sap in Bangladesh.

People in Bangladesh frequently drink fresh date palm sap. Fruit bats (Pteropus giganteus) also drink raw sap and may contaminate the sap by shedding Nipah virus through saliva and urine. In a previous study we identified two indigenous methods to prevent bats accessing the sap, bamboo skirts and lime (calcium carbonate). We conducted a pilot study to assess the acceptability of these two methods among sap harvesters. We used interactive community meetings and group discussions to encourage all the sap harvesters (n = 12) from a village to use either bamboo skirts or lime smear that some of them (n = 4) prepared and applied. We measured the preparation and application time and calculated the cost of bamboo skirts. We conducted interviews after the use of each method. The sap harvesters found skirts effective in preventing bats from accessing sap. They were sceptical that lime would be effective as the lime was washed away by the sap flow. Preparation of the skirt took ∼105 min. The application of each method took ∼1 min. The cost of the bamboo skirt is minimal because bamboo is widely available and they made the skirts with pieces of used bamboo. The bamboo skirt method appeared practical and affordable to the sap harvesters. Further studies should explore its ability to prevent bats from accessing date palm sap and assess if its use produces more or better quality sap, which would provide further incentives to make it more acceptable for its regular use.

A novel low-cost approach to estimate the incidence of Japanese encephalitis in the catchment area of three hospitals in Bangladesh.

Acute meningoencephalitis syndrome surveillance was initiated in three medical college hospitals in Bangladesh in October 2007 to identify Japanese encephalitis (JE) cases. We estimated the population-based incidence of JE in the three hospitals' catchment areas by adjusting the hospital-based crude incidence of JE by the proportion of catchment area meningoencephalitis cases who were admitted to surveillance hospitals. Instead of a traditional house-to-house survey, which is expensive for a disease with low frequency, we attempted a novel approach to identify meningoencephalitis cases in the hospital catchment area through social networks among the community residents. The estimated JE incidence was 2.7/100,000 population in Rajshahi (95% confidence interval [CI] = 1.8-4.9), 1.4 in Khulna (95% CI = 0.9-4.1), and 0.6 in Chittagong (95% CI = 0.4-0.9). Bangladesh should consider a pilot project to introduce JE vaccine in high-incidence areas.

Rates of hospital-acquired respiratory illness in Bangladeshi tertiary care hospitals: results from a low-cost pilot surveillance strategy.

BACKGROUND: Patients hospitalized in resource-poor health care settings are at increased risk for hospital-acquired respiratory infections due to inadequate infrastructure. METHODS: From 1 April 2007 through 31 March 2008, we used a low-cost surveillance strategy to identify new onset of respiratory symptoms in patients hospitalized for >72 h and in health care workers in medicine and pediatric wards at 3 public tertiary care hospitals in Bangladesh. RESULTS: During 46,273 patient-days of observation, we recorded 136 episodes of hospital-acquired respiratory disease, representing 1.7% of all patient hospital admissions; rates by ward ranged from 0.8 to 15.8 cases per 1000 patient-days at risk. We identified 22 clusters of respiratory disease, 3 of which included both patients and health care workers. Of 226 of heath care workers who worked on our surveillance wards, 61 (27%) experienced a respiratory illness during the study period. The cost of surveillance was US$43 per month per ward plus 30 min per day in data collection. CONCLUSIONS: Patients on these study wards frequently experienced hospital-acquired respiratory infections, including 1 in every 20 patients hospitalized for >72 h on 1 ward. The surveillance method was useful in calculating rates of hospital-acquired respiratory illness and could be used to enhance capacity to quickly detect outbreaks of respiratory disease in health care facilities where systems for outbreak detection are currently limited and to test interventions to reduce transmission of respiratory pathogens in resource-poor settings.