Wade Timothy J, Lin Cynthia J, Jagai Jyotsna S, Hilborn Elizabeth D
United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Environmental Public Health Division, Chapel Hill, North Carolina, United States of America.
Oak Ridge Institute for Science and Education (ORISE) Research Participation Program at the United States Environmental Protection Agency, Chapel Hill, North Carolina, United States of America; University of North Carolina, Gillings School of Global Public Health, Department of Epidemiology, Chapel Hill, North Carolina, United States of America.
PLoS One. 2014 Oct 17;9(10):e110474. doi: 10.1371/journal.pone.0110474. eCollection 2014.
Floods and other severe weather events are anticipated to increase as a result of global climate change. Floods can lead to outbreaks of gastroenteritis and other infectious diseases due to disruption of sewage and water infrastructure and impacts on sanitation and hygiene. Floods have also been indirectly associated with outbreaks through population displacement and crowding.
We conducted a case-crossover study to investigate the association between flooding and emergency room visits for gastrointestinal illness (ER-GI) in Massachusetts for the years 2003 through 2007. We obtained ER-GI visits from the State of Massachusetts and records of floods from the National Oceanic and Atmospheric Association's Storm Events Database. ER-GI visits were considered exposed if a flood occurred in the town of residence within three hazard periods of the visit: 0-4 days; 5-9 days; and 10-14 days. A time-stratified bi-directional design was used for control selection, matching on day of the week with two weeks lead or lag time from the ER-GI visit. Fixed effect logistic regression models were used to estimate the risk of ER-GI visits following the flood.
A total of 270,457 ER-GI visits and 129 floods occurred in Massachusetts over the study period. Across all counties, flooding was associated with an increased risk for ER-GI in the 0-4 day period after flooding (Odds Ratio: 1.08; 95% Confidence Interval: 1.03-1.12); but not the 5-9 days (Odds Ratio: 0.995; 95% Confidence Interval: 0.955-1.04) or the 10-14 days after (Odds Ratio: 0.966, 95% Confidence Interval: 0.927-1.01). Similar results were observed for different definitions of ER-GI. The effect differed across counties, suggesting local differences in the risk and impact of flooding. Statewide, across the study period, an estimated 7% of ER-GI visits in the 0-4 days after a flood event were attributable to flooding.
由于全球气候变化，预计洪水和其他恶劣天气事件将会增加。洪水可能会因污水和供水基础设施遭到破坏以及对环境卫生和个人卫生的影响，导致肠胃炎和其他传染病的爆发。洪水还通过人口流离失所和拥挤与疾病爆发存在间接关联。
我们开展了一项病例交叉研究，以调查2003年至2007年马萨诸塞州洪水与因胃肠道疾病前往急诊室就诊（ER-GI）之间的关联。我们获取了马萨诸塞州的ER-GI就诊数据以及美国国家海洋和大气管理局风暴事件数据库中的洪水记录。如果在就诊前三个危险时间段（0-4天、5-9天、10-14天）内，患者居住的城镇发生了洪水，那么此次ER-GI就诊被视为暴露。在选择对照时采用了时间分层双向设计，根据一周中的日期进行匹配，并提前或滞后两周与ER-GI就诊时间对应。使用固定效应逻辑回归模型来估计洪水后ER-GI就诊的风险。
在研究期间，马萨诸塞州共发生了270,457次ER-GI就诊和129次洪水。在所有县中，洪水与洪水发生后0-4天内ER-GI风险增加相关（比值比：1.08；95%置信区间：1.03-1.12）；但与5-9天内无关（比值比：0.995；95%置信区间：0.955-1.04），也与10-14天内无关（比值比：0.966，95%置信区间：0.927-1.01）。对于不同定义的ER-GI，观察到了类似结果。各县的影响有所不同，这表明洪水风险和影响存在地区差异。在全州范围内，在整个研究期间，洪水事件发生后0-4天内估计有7%的ER-GI就诊归因于洪水。
