Using rapid indicators for Enterococcus to assess the risk of illness after exposure to urban runoff contaminated marine water

WATER RESEARCH

卷:46

Article

Colford, John M., Jr.¹  Schiff, Kenneth C.²  Griffith, John F.²  Yau, Vince¹  Arnold, Benjamin F.¹  Wright, Catherine C.¹  Gruber, Joshua S.¹  Wade, Timothy J.³  Burns, Susan⁴  Hayes, Jacqueline⁴  McGee, Charles⁵  Gold, Mark⁶  Cao, Yiping²  Noble, Rachel T.⁷  Haugland, Richard⁸  Weisberg, Stephen B.² 

[1] Univ Calif Berkeley, Sch Publ Hlth, Berkeley, CA 94720 USA

[2] So Calif Coastal Water Res Project, Costa Mesa, CA 92626 USA

[3] US EPA, Natl Environm Hlth Effects Res Lab, Chapel Hill, NC 27711 USA

[4] Univ Calif Berkeley, Survey Res Ctr, Berkeley, CA 94720 USA

[5] Orange Cty Sanitat Dist, Fountain Valley, CA 92708 USA

[6] Heal Bay, Santa Monica, CA 90401 USA

[7] Univ N Carolina, Inst Marine Sci, Morehead City, NC 28557 USA

[8] US EPA, Natl Exposure Res Lab, Cincinnati, OH 45268 USA

关键词: Gastrointestinal illness;    Recreational water quality;    Diarrhea;    Indicator organisms;    qPCR;   

DOI  :  10.1016/j.watres.2012.01.033

来源: Elsevier

【 摘 要 】

Background: Traditional fecal indicator bacteria (FIB) measurement is too slow (>18 h) for timely swimmer warnings. Objectives: Assess relationship of rapid indicator methods (qPCR) to illness at a marine-beach impacted by urban runoff. Methods: We measured baseline and two-week health in 9525 individuals visiting Doheny Beach 2007-08. Illness rates were compared (swimmers vs. non-swimmers). FIB measured by traditional (Enterococcus spp. by EPA Method 1600 or Enterolert (TM), fecal coliforms, total coliforms) and three rapid qPCR assays for Enterococcus spp. (Taqman, Scorpion-1, Scorpion-2) were compared to health. Primary bacterial source was a creek flowing untreated into ocean; the creek did not reach the ocean when a sand berm formed. This provided a natural experiment for examining FIB-health relationships under varying conditions. Results: We observed significant increases in diarrhea (OR 1.90, 95% CI 1.29-2.80 for swallowing water) and other outcomes in swimmers compared to non-swimmers. Exposure (body immersion, head immersion, swallowed water) was associated with increasing risk of gastrointestinal illness (GI). Daily GI incidence patterns were different: swimmers (2-day peak) and non-swimmers (no peak). With berm-open, we observed associations between GI and Traditional and rapid methods for Enterococcus; fewer associations occurred when berm status was not considered. Conclusions: We found increased risk of GI at this urban runoff beach. When FIB source flowed freely (berm-open), several traditional and rapid indicators were related to illness. When FIB source was weak (berm-closed) fewer illness associations were seen. These different relationships under different conditions at a single beach demonstrate the difficulties using these indicators to predict health risk. (C) 2012 Elsevier Ltd. All rights reserved.

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