Vibrio in seafood - FAO.org

Table 5.3. Instances of fish implicated as vehicles for transmission of V. choleraeSite Year Fish involved ReferencePhilippines 1962 Raw shrimp Felsenfeld, 1972Italy 1973 Raw mussels Baine et al., 1974Portugal 1974 Raw and undercooked shellfish Blake et al., 1977bGuam 1974 Salted raw fish Merson et al., 1977Gilbert Islands 1977 Raw and salted fish And clams McIntyre et al., 1979Louisiana 1978 Cooked crabs Blake et al., 1980Singapore 1982 Cooked squid Goh et al., 1984Louisiana 1986 Cooked crab, cooked or raw shrimp Lowry et al., 1989Guinea-Bissare 1987 Cooked crabs Shaffer et al., 1988Colarado 1988 Raw oyster CDC, 1989Chuck 1990 Raw fish Swerdlow et al., 1991Ecuador 1991 Seafood CDC, 1991Japan 1991 Imported clams Anon, 1991Hong Kong 1994 Seafood Kam et al., 19955.2.5 Consumption of shrimpShrimp is widely consumed both in developing countries and developed countries. In most Asianshrimp producing countries, large sized high quality shrimp goes to the export market and only small sizedvarieties are consumed locally. Estimates of the volume of shrimp consumed are available for very fewcountries. In Australia, 18,791 tonnes of locally produced and 10,106 tonnes of imported prawns areconsumed annually. Assuming that the consumption in one meal is 150g, this equates with 192,647,000servings. It is also estimated that 25% of Australians consume prawns.5.2.6 Modelling exposure5.2.6.1 ApproachesExposure assessment involves estimation of the likelihood of ingesting toxigenic V. cholerae O1and O139 by eating shrimp contaminated with these organisms and the amount of the organismsconsumed. Since most of the world’s shrimp production and processing occurs in developing countries inAsia and Latin America, where cholera is endemic, there can be multiple modes of contamination.Therefore, exposure assessment should consider possibilities of contamination during harvesting, postharvesthandling, processing, retail and at the consumer end during preparation for consumption. Twomodels are being proposed, one for shrimp harvested from tropical coastal environment, handled andmarketed in domestic markets of developing countries (Figure 5.1) and another for shrimpharvested/cultured and processed in tropical developing countries, and consumed in developed countries(Figure 5.2).94