Epidemiology of Cholera in Bangladesh: Findings From Nationwide Hospital-based Surveillance, 2014–2018

Abstract

Background Despite advances in prevention, detection, and treatment, cholera remains a major public health problem in Bangladesh and little is known about cholera outside of limited historical sentinel surveillance sites. In Bangladesh, a comprehensive national cholera control plan is essential, although national data are needed to better understand the magnitude and geographic distribution of cholera. Methods We conducted systematic hospital-based cholera surveillance among diarrhea patients in 22 sites throughout Bangladesh from 2014 to 2018. Stool specimens were collected and tested for Vibrio cholerae by microbiological culture. Participants’ socioeconomic status and clinical, sanitation, and food history were recorded. We used generalized estimating equations to identify the factors associated with cholera among diarrhea patients. Results Among 26 221 diarrhea patients enrolled, 6.2% (n = 1604) cases were V. cholerae O1. The proportion of diarrhea patients positive for cholera in children <5 years was 2.1% and in patients ≥5 years was 9.5%. The proportion of cholera in Dhaka and Chittagong Division was consistently high. We observed biannual seasonal peaks (pre- and postmonsoon) for cholera across the country, with higher cholera positivity during the postmonsoon in western regions and during the pre–monsoon season in eastern regions. Cholera risk increased with age, occupation, and recent history of diarrhea among household members. Conclusions Cholera occurs throughout a large part of Bangladesh. Cholera-prone areas should be prioritized to control the disease by implementation of targeted interventions. These findings can help strengthen the cholera-control program and serve as the basis for future studies for tracking the impact of cholera-control interventions in Bangladesh.

Vibrio cholerae O1 transmission in Bangladesh: insights from a nationally representative serosurvey

“…Based on limited data from clinical sentinel surveillance, cholera case reports in 2015 were consistent with historic trends. 24 However, our estimates might not generalise to all future years because of natural variation in infection incidence driven by both intrinsic and extrinsic factors. Among the individual-level, household-level, and community-level covariates considered by us, only age was a strong predictor of risk for seropositivity.…”

Genome-wide analysis provides a deeper understanding of the population structure of the Salmonella enterica serotype Paratyphi B complex in Bangladesh

“…In this study, we coupled an existing nationwide enteric disease surveillance study across Bangladesh with a WGS approach to investigate the genomic epidemiology of S. enterica serotype Paratyphi B complex. Our surveillance showed that, in Bangladesh, the prevalence of S. Paratyphi B isolates is low (0.36%) compared to other enteric pathogens in this surveillance study [14]. Moreover, where previous studies have only reported serotyping results of S. Paratyphi B strains [53], this is the first study in Bangladesh to distinguish between S. Java and S. Paratyphi B sensu stricto biotypes, using WGS to confirm that S. Java is the variant responsible for the diarrhoeal disease in Bangladesh.…”

“…This study utilized samples collected from an established nationwide enteric disease surveillance system being carried out in 10 hospitals across 8 divisions of Bangladesh in a collaboration between the Institute of Epidemiology, Disease Control and Research (IEDCR) and icddr,b (, ). The surveillance sites were selected based on reports of acute watery diarrhoea according to the national District Health Information Software v2 Database from Directorate General of Health Services (DGHS) [14, 15]. It is a large, longitudinal, multi-pathogen surveillance study that included diarrhoeal patients infected with a variety of enteric pathogens: Vibrio cholerae , ETEC, Shigella , and typhoidal and non-typhoidal Salmonella .…”

“…for Vibrio cholerae was 1.10-18.3 % of patients[14]) (Table1). The Narshingdi district hospital in the Dhaka division had the highest percentage of S. Paratyphi B-positive patients (1.12 %) in this study.Of the 107 S. Paratyphi B-positive samples, only 79 S. Paratyphi B strains were available for sequencing in this study.…”

Clinical cholera surveillance sensitivity in Bangladesh and implications for large-scale disease control

“…Bangladesh has among the highest national rates of Vibrio cholerae infection in the world [1]; a nationally-representative serosurvey estimated that roughly 17% (95% CI: 11-24%) of the 165 million people living in Bangladesh experienced infection in 2015 [2]. In 2014, the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) and the Institute of Epidemiology Disease Control And Research (IEDCR) established a nationwide sentinel surveillance system with the goal of monitoring the seasonality and geographic trends in acute cases and identifying geographic areas with a high burden of laboratory-confirmed clinical cholera [3]. The participating 22 sentinel hospital sites and the icddr,b Dhaka hospital are the only healthcare facilities that regularly perform laboratory confirmation of V. cholerae in the country [3].…”