Background A surveillance system that is sensitive to detecting high burden areas is critical for achieving widespread disease control. In 2014, Bangladesh established a nationwide, facility-based cholera surveillance system for Vibrio cholerae infection. We sought to measure the sensitivity of this surveillance system to detect cases to assess whether cholera elimination targets outlined by the Bangladesh national control plan can be adequately measured. Methods We overlaid maps of nationally representative annual V cholerae seroincidence onto maps of the catchment areas of facilities where confirmatory laboratory testing for cholera was conducted, and we identified its spatial complement as surveillance greyspots, areas where cases likely occur but go undetected. We assessed surveillance system sensitivity and changes to sensitivity given alternate surveillance site selection strategies. Results We estimated that 69% of Bangladeshis (111.7 million individuals) live in surveillance greyspots and that 23% (25.5 million) of these individuals live in areas with the highest V cholerae infection rates. Conclusions The cholera surveillance system in Bangladesh has the ability to monitor progress towards cholera elimination goals among 31% of the country’s population, which may be insufficient for accurately measuring progress. Increasing surveillance coverage, particularly in the highest risk areas, should be considered.

中文翻译：

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孟加拉国的临床霍乱监测敏感性及其对大规模疾病控制的意义

背景 对检测高负担地区敏感的监测系统对于实现广泛的疾病控制至关重要。2014 年，孟加拉国建立了一个全国性的、以设施为基础的霍乱弧菌感染监测系统。我们试图衡量该监测系统检测病例的敏感性，以评估孟加拉国国家控制计划中概述的霍乱消除目标是否可以得到充分衡量。方法 我们将具有全国代表性的年度霍乱弧菌血清发病率地图叠加到进行霍乱确认性实验室检测的设施集水区的地图上，并将其空间补充确定为监测灰点，即可能发生病例但未被发现的区域。我们评估了监测系统的敏感性和给定替代监测地点选择策略的敏感性变化。结果 我们估计，69% 的孟加拉人（1.117 亿人）生活在监控灰点，其中 23%（2550 万人）生活在霍乱弧菌感染率最高的地区。结论 孟加拉国的霍乱监测系统能够监测该国 31% 人口实现消除霍乱目标的进展情况，这可能不足以准确衡量进展情况。应考虑增加监测覆盖率，特别是在风险最高的地区。500 万）这些人生活在霍乱弧菌感染率最高的地区。结论 孟加拉国的霍乱监测系统能够监测该国 31% 人口实现消除霍乱目标的进展情况，这可能不足以准确衡量进展情况。应考虑增加监测覆盖率，特别是在风险最高的地区。500 万）这些人生活在霍乱弧菌感染率最高的地区。结论 孟加拉国的霍乱监测系统能够监测该国 31% 人口实现消除霍乱目标的进展情况，这可能不足以准确衡量进展情况。应考虑增加监测覆盖率，特别是在风险最高的地区。