Desenclos J C
Réseau National de Santé Publique, Saint-Maurice.
Rev Epidemiol Sante Publique. 1996 Oct;44(5):437-54.
For feeding purposes shellfish filter large amounts of water but also concentrate infectious agents and toxins that are present in the marine environment either naturally or because of pollution. Thus, the consumption of raw or undercooked shellfish is a substantial source of foodborne poisoning, mostly epidemic and sometimes sporadic. Most of shellfish-borne infectious diseases are linked to fecal contamination of the marine environment; they include: thyphoid fever, salmonellosis, shigellosis, campylobacteriosis, cholera, Norwalk or Norwalk-like gastroenteritis and hepatitis A. In warm climates, shellfish contains naturally occurring halopilic Vibrios and may cause severe sporadic infections (septicemias) among very susceptible consumers (immunocompromised). Shellfish also causes outbreaks of paralytic shellfish poisoning (PSP) and diarrheic shellfish poisoning (DSP) when they are contaminated by toxins produced when Dinophisis, a marine plancton, proliferates. Chemical compounds (heavy metals and organic toxins) that are dumped in the environment (soil, air, and water) also reach shellfish harvesting waters where they are cocentrated. Although acute or chronic effects of the chemical contamination of shellfish have not been clearly documented, the cadmium pollution of some shellfish harvesting waters raises a serious problem. Since it is impossible to prevent completely the contamination of coastal waters by any of the agents cited above, the prevention of shellfish-borne diseases requires monitoring of the marine environment and shellfish flesh (coliform count, Dinophysis toxins, heavy metals...). This surveillance allows the classification of growing areas as suitable or not for harvesting and distribution of shellfish. However, this surveillance is not always sensitive enough. Indicators of fecal pollution are particularly not reliable for shellfish viral contamination. A better knowledge of marine biology, the limitation of coastal waters pollution, improved surveillance, the development of more sensitive indicators, the responsabilisation of the industry and the information of the public on the health hazards associated with shellfish consumption are the key issues for the improvement of shellfish-borne disease prevention.
出于摄食目的，贝类会过滤大量海水，同时也会富集海洋环境中天然存在或因污染而存在的传染源和毒素。因此，食用生的或未煮熟的贝类是食源性中毒的一个重要来源，大多为群体性发病，有时也有散发病例。大多数由贝类传播的传染病都与海洋环境的粪便污染有关；这些疾病包括：伤寒、沙门氏菌病、志贺氏菌病、弯曲菌病、霍乱、诺沃克或类诺沃克肠胃炎以及甲型肝炎。在温暖气候下，贝类含有天然存在的嗜盐弧菌，可能会在极易感染的消费者（免疫功能低下者）中引发严重的散发性感染（败血症）。当贝类被海洋浮游生物迪氏藻大量繁殖时产生的毒素污染时，还会引发麻痹性贝类中毒（PSP）和腹泻性贝类中毒（DSP）疫情。排放到环境（土壤、空气和水）中的化合物（重金属和有机毒素）也会进入贝类捕捞水域并在其中富集。尽管贝类化学污染的急性或慢性影响尚未得到明确记录，但一些贝类捕捞水域的镉污染引发了严重问题。由于不可能完全防止上述任何一种因素对沿海水域的污染，预防贝类传播疾病需要对海洋环境和贝类肉质进行监测（大肠菌群计数、迪氏藻毒素、重金属……）。这种监测可以将养殖区域分类为适合或不适合贝类捕捞和销售。然而，这种监测并不总是足够灵敏。粪便污染指标对于贝类病毒污染尤其不可靠。更好地了解海洋生物学、限制沿海水域污染、改进监测、开发更灵敏的指标、加强行业责任以及向公众宣传与食用贝类相关的健康危害，是改善贝类传播疾病预防工作的关键问题。
