Epidemiology Directorate, Ministry of Agriculture, Addis Ababa, Ethiopia.
Field Epidemiology Training Program, School of Public Health, Addis Ababa University, Ethiopia.
PLoS One. 2020 Jul 2;15(7):e0235440. doi: 10.1371/journal.pone.0235440. eCollection 2020.
Cholera remains a significant public health problem in more than one-third of the countries of the world. Cholera outbreak has become more common in Addis Ababa particularly in the rainy seasons; however, there is a paucity of data on risk factors associated with cholera outbreaks rendering interventions difficult. We investigated the outbreak to identify its etiology, source, risk factors and in order to control the outbreak.
We compared cases with health center-based unmatched controls (1:2). Cases were patients aged ≥5 years with acute watery diarrhea, with or without vomiting while controls were persons aged ≥5 years without history of acute watery diarrhea. We interviewed our study participants using structured questionnaire to collect demographic and cholera risk factors data. We described the outbreak over time, and then tested our hypotheses using unconditional logistic regression.
The outbreak began on 7 September, 2017 reaching its peak on 23 September, 2017 and ended on 01 October, 2017. We identified a total of 25 cases (Median age: 38 years; IQR: 20 years) and recruited 50 controls (Median age: 35 years; IQR: 29 years). All case-patients had acute watery diarrhea and dehydration requiring intravenous fluids. All cases were admitted to cholera treatment center but there were no deaths. Stool and water samples yielded isolates of Vibrio cholerae O1 of serological subtype Ogawa. Consumption of contaminated holy water (AOR: 20.5, 95%CI: 3.50, 119.61) and raw vegetables (AOR: 15.3, 95%CI: 3, 81.51) were independent risk factors whereas washing hands with soap after visiting latrine (AOR: 0.04, 95%CI: 0.01, 0.25) was independent protective factor.
Our findings demonstrated cholera foodborne transmission via consumption of raw vegetables, and its waterborne transmission via consumption of contaminated holy water. Washing hands with soap after visiting latrine was protective. We recommended cooking of vegetables and promoting hand washing.
霍乱仍然是世界上三分之一以上国家的重大公共卫生问题。在亚的斯亚贝巴，特别是在雨季，霍乱爆发变得更加常见；然而，由于缺乏与霍乱爆发相关的风险因素数据，干预措施变得困难。我们调查了这次爆发，以确定其病因、来源、危险因素，并为了控制这次爆发。
我们将病例与基于卫生中心的匹配对照（1:2）进行了比较。病例是年龄≥5 岁、有急性水样腹泻、伴有或不伴有呕吐的患者，而对照是年龄≥5 岁、无急性水样腹泻史的人。我们使用结构化问卷对我们的研究参与者进行了访谈，以收集人口统计学和霍乱危险因素数据。我们按时间描述了这次爆发，然后使用非条件逻辑回归检验了我们的假设。
这次爆发始于 2017 年 9 月 7 日，于 2017 年 9 月 23 日达到高峰，于 2017 年 10 月 1 日结束。我们共发现 25 例病例（中位年龄：38 岁；IQR：20 岁），招募了 50 名对照（中位年龄：35 岁；IQR：29 岁）。所有病例患者均有急性水样腹泻和需要静脉补液的脱水。所有病例均被收治在霍乱治疗中心，但无死亡病例。粪便和水样标本分离出血清型 Ogawa 的霍乱弧菌 O1 菌株。饮用受污染的圣泉水（AOR：20.5，95%CI：3.50，119.61）和生食蔬菜（AOR：15.3，95%CI：3，81.51）是独立的危险因素，而便后用肥皂洗手（AOR：0.04，95%CI：0.01，0.25）是独立的保护因素。
我们的研究结果表明，霍乱通过食用生蔬菜发生食源性传播，通过饮用受污染的圣泉水发生水传播。便后用肥皂洗手有保护作用。我们建议烹饪蔬菜并促进洗手。
