Evaluation of shellfish sanitary quality by indicators of sewage pollution

The study described here was concerned with use of the coliform test to assess the danger of pollution by bacterial or viral pathogens, and its significance as a criterion of the sanitary quality of shellfish. Public health aspects of the sanitary status indicated for shellfish growing in waters polluted by sewage discharges are considered. Shellfish examinations were conducted in New Hampshire and Galveston Bay estuaries. The eastern oyster, Crassostrea virginica, was used throughout these examinations. Information on the sanitary quality of shellfish and shellfish waters was obtained from the results of coliform, salmonella, and enteric virus tests. Results showed that the fecal coliform index provided useful information on the presence of salmonellae and viruses in shellfish when the fecal pollution measured was moderate to excessive. Inadequacies of the index were detected increasingly wit declining levels of pollution, the most pronounced inadequacies occurred in the presence of enteric viruses. Reasons for this discrepancy, and ways of overcoming it are discussed