“…Shellfish contamination with pathogenic microorganisms, mainly Salmonella, Vibrio parahaemolyticus, Vibrio cholerae, and hepatites virus type A, have been extensively reported in the literature (Andrews et a1.,1975;Gelli et al, 1976Gelli et al, , 1979Gerba and Goyal, 1978;Joseph et a1.,1982;Slanetz, 1968;Twedt et al, 1981;West, 1989;Wood, 1976) and these contaminated bivalve molluscs have been involved with gastroenteritis outbreaks in several countries (Baine, 1974;Blake et al, 1978;Dutt et al, 1971;Gottfried et al, 1987;Levin, 1978;Merson et al, 1976;Portnoy et al, 1975).…”