Epidemiologic evaluation of multiple alternate microbial water quality monitoring indicators at three California beaches
Epidemiologic evaluation of multiple alternate microbial water quality monitoring indicators at three California beaches
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DOI：
10.1016/j.watres.2016.02.036
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发表时间：
2016-05-01
期刊：
影响因子：
12.8
通讯作者：
Colford, John M., Jr.
中科院分区：
文献类型：
--
作者：
Griffith, John F.;Weisberg, Stephen B.;Colford, John M., Jr.
简介：分子方法的进步为直接测量粪便污染的病原体或宿主相关标志物提供了新的机会，而不是仅仅依靠粪便指示菌（FIB）进行海滩水质监测。采用新指标取决于确定指标的存在或浓度与游泳者疾病之间的关系。在这里，我们介绍了三项流行病学研究的结果，其中通过培养或分子方法同时测量了粪便污染的广泛细菌和病毒指标以及肠球菌，以评估它们是否比目前的娱乐水质微生物指标提供更好的健康风险预测。方法：我们于2007年、2008年和2009年夏季在加利福尼亚的三个海滩——阿瓦隆湾（Avalon）、多亨利州立海滩（Doheny）、冲浪者州立海滩（Malibu）——进行了前瞻性队列研究。这些研究招募了10785名游泳者，记录了每个游泳者的水暴露情况。每天在每个海滩的多个地点收集多次水和沙样本，并使用67种不同的方法对多达41个目标指标进行分析。10-14天后，采访者通过电话联系参与者，记录他们在海滩之旅后出现的胃肠道疾病症状。采用回归模型评估各滩涂水质指标与游泳者胃肠道疾病的关系。结果：在两个海滩上，F+噬菌体（使用EPA方法1602测量）与胃肠道疾病的关联比EPA方法1600更强，而分子方法F+ RNA噬菌体基因型II是马里布唯一与胃肠道疾病显著相关的指标。MRSA，一种已知的病原体，在阿瓦隆测量的所有微生物中与胃肠道疾病的关联最强。有两种方法针对人类相关的粪便厌氧细菌，它们与胃肠道疾病的相关性比EPA方法1600更强，但仅在Avalon。没有指标组合的比值比始终高于EPA 1600方法，但一种基于在海滩检测到的病原体数量的复合指标在淡水流量高时与Avalon和Doheny的胃肠道疾病显著相关。讨论：虽然EPA Method1600在两个海滩上表现良好，基于其与胃肠道疾病的相关性的一致性及其估计相关性的准确性，但EPA Method 1602测量的F+噬菌体在测量的两个海滩的高风险条件下与胃肠道疾病的相关性更强。在马里布，F+噬菌体基因型II是唯一与胃肠道疾病显著相关的指标。一些指标，特别是那些针对人类相关细菌的指标，显示出与胃肠道疾病的关系等于或大于阿瓦隆EPA方法1600的结果，该方法有一个集中的人类粪便来源。我们的研究结果表明，每个海滩的具体情况决定了哪种或哪种指标最能预测胃肠道疾病。(C) 2016 Elsevier Ltd.版权所有。
Introduction: Advances in molecular methods provide new opportunities for directly measuring pathogens or host-associated markers of fecal pollution instead of relying on fecal indicator bacteria (FIB) alone for beach water quality monitoring. Adoption of new indicators depends on identifying relationships between either the presence or concentration of the indicators and illness among swimmers. Here we present results from three epidemiologic studies in which a broad range of bacterial and viral indicators of fecal contamination were measured simultaneously by either culture or molecular methods along with Enterococcus to assess whether they provide better health risk prediction than current microbial indicators of recreational water quality.Methods: We conducted prospective cohort studies at three California beaches - Avalon Bay (Avalon), Doheny State Beach (Doheny), Surfrider State Beach (Malibu) - during the summers of 2007, 2008 and 2009. The studies enrolled 10,785 swimmers across the beaches and recorded each swimmer's water exposure. Water and sand samples were collected several times per day at multiple locations at each beach and analyzed for up to 41 target indicators using 67 different methodologies. Interviewers contacted participants by phone 10-14 days later and recorded symptoms of gastrointestinal illness occurring after their beach visit. Regression models were used to evaluate the association between water quality indicators and gastrointestinal illness among swimmers at each beach.Results: F+ coliphage (measured using EPA Method 1602) exhibited a stronger association with GI illness than did EPA Method 1600 at the two beaches where it was measured, while a molecular method, F+ RNA Coliphage Genotype II, was the only indicator significantly associated with GI illness at Malibu. MRSA, a known pathogen, had the strongest association with GI illness of any microbe measured at Avalon. There were two methods targeting human-associated fecal anaerobic bacteria that were more strongly associated with GI illness than EPA Method 1600, but only at Avalon. No indicator combinations consistently had a higher odds ratio than EPA Method 1600, but one composite indicator, based on the number of pathogens detected at a beach, was significantly associated with gastrointestinal illness at both Avalon and Doheny when freshwater flow was high.Discussion: While EPA Method1600 performed adequately at two beaches based on its consistency of association with gastrointestinal illness and the precision of its estimated associations, F+ coliphage measured by EPA Method 1602 had a stronger association with GI illness under high risk conditions at the two beaches where it was measured. One indicator, F+ Coliphage Genotype II was the only indicator significantly associated with GI illness at Malibu. Several indicators, particularly those targeting human associated bacteria, exhibited relationships with GI illness that were equal to or greater than that of EPA Method 1600 at Avalon, which has a focused human fecal source. Our results suggest that site-specific conditions at each beach determine which indicator or indicators best predict GI illness. (C) 2016 Elsevier Ltd. All rights reserved.