Can cholera ‘hotspots’ be converted to cholera ‘coldspots’ in cholera endemic countries? The Matlab, Bangladesh experience

K Zaman,Deok Ryun Kim,Mohammad Ali,Faisal Ahmmed,Justin Im,Md Taufiqul Islam,Ashraful Islam Khan,Md Yunus,Md Alfazal Khan,Florian Marks,Firdausi Qadri,Jerome Kim,John D Clemens

doi:10.1016/j.ijid.2020.02.055

Abstract

BackgroundCholera remains a major public health threat in low- and middle-income countries. The World Health Organization (WHO) has recently launched a global initiative to end preventable cholera by 2030. Key to the success of this initiative will be the elimination of cholera transmission in cholera ‘hotspots’ with regularly recurrent disease; this can be achieved via improved surveillance to define hotspot populations, through the use of oral cholera vaccines, and through the implementation of improved water, sanitation, and hygiene (WASH). MethodsThis study was performed to analyze the trend in cholera incidence during the years 1974–2018 in Matlab, Bangladesh (defined population of about 200 000) that has been recognized as one of the world’s cholera hotspots. During this period, Matlab has maintained a demographically defined population and comprehensive, culture-based surveillance for cholera, supplemented by periodic surveys to characterize the socioeconomic status of the population, as well as water sources and facilities for defecation. ResultsCholera transmission has nearly been eliminated in Matlab, despite a continuing high cholera burden in many other parts of Bangladesh and despite trends of increasing ambient and sea surface temperatures, which are known to increase cholera incidence. Concomitantly, the socioeconomic status of the population has increased modestly, and the use of simple tubewells for drinking water has reached 95% and the installation of sanitary latrines has reached 85%. ConclusionsThe factors responsible for the decline in cholera are difficult to pinpoint precisely, but this decline has occurred with the installation of inexpensive improvements in water sources and latrines and despite environmental factors that should have augmented cholera incidence. These observations lend optimism to the current global initiative to end preventable cholera by 2030.

Highlights

Cholera remains a major public health threat in low- and middle-income countries
The World Health Organization (WHO) has proposed a bold initiative to end cholera by 2030. Key to this initiative is the assumption that cholera in endemic countries is driven by ‘hotspots’, that these hotspots can be identified through improved cholera surveillance, and that the use of oral cholera vaccines (OCVs) and implementation of improved water, sanitation, and hygiene (WASH) in the hotspot populations can prevent cholera transmission, benefitting the hotspot populations, and populations residing outside the hotspots to which cholera may spread
As the widespread installation of municipal water and sewerage systems in low- and middle-income countries (LMICs) is too expensive for contemplation before 2030, it might be questioned whether cholera transmission in cholera hotspots in endemic countries can be controlled with more affordable WASH investments

Summary

Introduction

Cholera remains a major public health threat in low- and middle-income countries. The World Health Organization (WHO) has recently launched a global initiative to end preventable cholera by 2030. The situation is quite different in LMICs, despite several global initiatives to improve access to clean water and adequate sanitation.

Results

Conclusion