Miossec L, Le Guyader F, Haugarreau L, Pommepuy M
IFREMER, Département Microbiologie et Phycotoxines, Laboratoire de Microbiologie, Rue de l'Ile d'Yeu, BP 21105, 44311 Nantes Cedex. 3
Rev Epidemiol Sante Publique. 2000 Aug;48 Suppl 2:2S62-71.
Sewage treatments are not efficient to eliminate enteric microorganisms. Viruses are able to persist and are discharged into the marine environment with treated effluents. Few data are now available on the magnitude and the contributive processes of marine viral contamination. This work evaluates the relationship between the magnitude of rainfall and the viral contamination of the marine environment during winter epidemics of gastroenteritis in human coastal populations.
A RT-PCR method was used to detect enterovirus, hepatitis A virus, Norwalk-like virus, astrovirus and rotavirus in shellfish, harvested monthly between August 1995 and July 1998. The frequency of virus detection in shellfish was expressed as an Index of Viral Contamination. Acute gastroenteritis in the population was estimated using the French Sentinel System for Monitoring of Communicable Diseases. Rainfall effects on the efficiency of sewage treatment were assessed using an estimated staying time of sewage effluents in the plant.
The results indicate that the highest viral contamination occurs in winter. Maximal indexes of viral contamination were respectively 70% in January 1996, 100% in January 1997, but only 31% in January 1998. Viral contamination variations seemed to follow the pattern of the winter epidemic of acute gastroenteritis in the local population in 1996 and 1997. These observations should be linked to the winter rainfalls. Heavy rains on short periods of time could create an hydraulic overload in the sewage treatment plant, reducing the staying time of the sewage effluents and thus the efficiency of the disinfection process.
The magnitude of the viral contamination of shellfish seems to result from the simultaneity between the winter epidemics of acute gastroenteritis in the coastal population and heavy rainfall. To prevent public health hazards associated with shellfish consumption, the monitoring of microbiological quality in shellfish harvesting areas should include accompagning survey of viral epidemic in the coastal population, and of sewage outputs in the coastal environment.
污水处理在消除肠道微生物方面效率不高。病毒能够持续存在，并随着处理后的污水排放到海洋环境中。目前关于海洋病毒污染程度和促成过程的数据很少。这项研究评估了人类沿海地区冬季肠胃炎流行期间降雨量与海洋环境病毒污染之间的关系。
采用逆转录聚合酶链反应（RT-PCR）方法检测1995年8月至1998年7月每月采集的贝类中的肠道病毒、甲型肝炎病毒、诺如病毒、星状病毒和轮状病毒。贝类中病毒检测频率以病毒污染指数表示。使用法国传染病监测哨兵系统估计人群中的急性肠胃炎情况。利用污水在处理厂的估计停留时间评估降雨对污水处理效率的影响。
结果表明，最高的病毒污染发生在冬季。1996年1月病毒污染的最大指数分别为70%，1997年1月为100%，但1998年1月仅为31%。1996年和1997年，病毒污染变化似乎与当地人群冬季急性肠胃炎流行模式一致。这些观察结果应与冬季降雨相关联。短时间的暴雨可能会使污水处理厂产生水力过载，减少污水停留时间，从而降低消毒过程的效率。
贝类的病毒污染程度似乎是沿海人群冬季急性肠胃炎流行与暴雨同时发生的结果。为防止与食用贝类相关的公共卫生危害，贝类捕捞区微生物质量监测应包括对沿海人群病毒流行情况和沿海环境污水排放情况的同步调查。
