Cholera, a deadly waterborne disease, remains a major threat in many areas of the world, including the Bengal Delta region. In this region, cholera outbreaks have two annual peaks; the first occurs during the dry season in the spring, and the second occurs in the fall following the wet season. However, the large-scale hydroclimatic processes underlying the propagation of the disease have not been well understood.
Akanda et al. show that cholera outbreaks in the Bengal Delta region propagate from the coast to inland and from spring to fall following two distinct transmission cycles. The first outbreak begins in the spring near the coast when northward movement of plankton-rich seawater and increasing salinity promote the growth of cholera-causing bacteria in rivers, which are used for irritation, sanitation, and consumption. The second outbreak begins in the fall, after summer floods and monsoons affects sanitation conditions that aid in bacterial transmission by contaminating waters over much of Bangladesh.
The authors find that while spring cholera outbreaks appear to affect further outbreaks in the subsequent fall season, fall outbreaks do not affect cholera outbreaks in the following spring. This analysis could help in using dry season water management as a tool for reducing cholera burden throughout the year and developing climate-based warning of cholera outbreaks, and inform prevention and intervention strategies in affected regions.
Water Resources Research, doi: 10.1029/2010WR009914, 2011
Title: Hydroclimatic influences on seasonal and spatial cholera transmission cycles: Implications for public health intervention in the Bengal Delta
Ali Shafqat Akanda and Antarpreet S. Jutla: Water and Environmental Research, Education, and Actionable Solutions Network, Departm
|Contact: Maria-Jos Vias|
American Geophysical Union