Epidemiology and clinical profile of diarrhea associated with enterotoxigenic Escherichia coli and Vibrio cholerae in Bangladesh: Findings from a hospital-based surveillance system, 2008-2023.

BACKGROUND: Enterotoxigenic Escherichia coli (ETEC) and Vibrio cholerae are notable enteric bacterial pathogens that cause diarrheal illnesses in resource-limited settings (e.g., Bangladesh). We aimed to explore the epidemiology and the clinical presentation of diarrhea caused by either V. cholerae or ETEC as a single-pathogen, or as a co-infection with both pathogens among patients requiring hospitalization. METHODS: We conducted the study using data from the Diarrheal Diseases Surveillance System of Dhaka Hospital, icddr,b from 2008 to 2023. A multivariable logistic regression model was used to characterize association of identified bacterial pathogens with specific clinical features. RESULTS: Among 43,483 diarrheal patients who received hospital care, 11% (4540/43,483) tested positive for V. cholerae, 8% (3070/43,483) had ETEC, and 1.5% (630/43,483) had co-infection. In 2023, the frequencies of ETEC, V. cholerae, and co-infection with both pathogens among patients were 7.5%, 4.5%, and 7.5%, respectively. After adjusting for covariates, co-infected cases showed significantly higher odds of severe outcomes, including watery stools (aOR: 12.33), high stooling frequency (>10/day, aOR: 1.50), vomiting (aOR: 3.16), and intravenous rehydration (aOR: 8.70) compared to single-pathogen infections. Clinical features among patients infected with single pathogens also varied. V. cholerae-positive cases were associated with dehydration [aOR:5.64;95%CI:(4.94,6.43)] and length of hospital stay [aOR:1.81;95%CI:(1.68,1.94)] relative to V. cholerae-negative cases. ETEC-positive cases were more likely to present with watery stools [aOR:1.26;95%CI:(1.04,1.53)], dehydration [aOR:1.23;95%CI:(1.12,1.35)], and the requirement for intravenous fluid rehydration [aOR:1.15;95%CI:(1.04,1.27)] relative to ETEC-negative cases. Overall, the clinical presentations of patients with ETEC single infection were less severe compared to patients with V. cholerae as a single infection or co-infection. CONCLUSIONS: Co-infection with V. cholerae and ETEC results in more severe clinical manifestations requiring intensive medical management compared to single-pathogen infections. These findings highlight the need for enhanced clinical preparedness and consideration of testing for both pathogens to optimize patient care. Our findings highlight the potential value of vaccines targeting ETEC and V. cholerae to improve protection.