Estimating the gap between clinical cholera and true community infections: findings from an integrated surveillance study in an endemic region of Bangladesh

Abstract

Our understanding of cholera transmission and burden largely rely on clinic-based surveillance, which can obscure trends, bias burden estimates and limit the impact of targeted cholera-prevention measures. Serologic surveillance provides a complementary approach to monitoring infections, though the link between serologically-derived infections and medically-attended disease, shaped by immunological, behavioral, and clinical factors, remains poorly understood. We unravel this cascade in a cholera-endemic Bangladeshi community by integrating clinic-based surveillance, healthcare seeking, and longitudinal serological data through statistical modeling. We found >50% of the study population had a V. cholerae O1 infection annually, and infection timing was not consistently correlated with reported cases. Four in 2,340 infections resulted in symptoms, only one of which was reported through the surveillance system. These results provide new insights into cholera transmission dynamics and burden in the epicenter of the 7th cholera pandemic and provide a framework to synthesize serological and clinical surveillance data.

Cholera vaccine clinical trials: A cross-sectional analysis of clinical trials registries

“…11 Zimbabwe is one country that has constantly reported a high number of cases, posing a risk of this disease spreading to many parts of Africa. 9 The findings suggests that more Cholera vaccine trials (i.e., 37%) are conducted in places that require the least efforts to reduce the spread of the disease. Research also indicates that more efforts are made for travelers from upper middle-income countries traveling to Cholera affected areas to receive Cholera vaccines or chemoprophylaxis.…”

“…Since mid-2021, the world has been facing an acute upsurge of multiple Cholera outbreaks, especially in areas that are not endemic for Cholera, with high mortality rates. 9 World Health Organisation (WHO) for African and Eastern Mediterranean regions had 23 countries reporting Cholera outbreaks in 2021. 10 The trend continued into 2023, with over 30 countries reporting Cholera cases or outbreaks in five WHO regions.…”