DIFFERENCES AMONG MARINE AND HOSPITAL STRAINS OF VIBRIO-CHOLERAE DURING PERUVIAN EPIDEMIC

During a period of 18 months of an epidemic of Vibrio cholerae, cultur es from 450 samples of fish, shellfish and seawater were isolated. The highest frequencies of occurrence observed were 5.2% in fish from ins hore waters, 3.9% in marine snails, and 1.8% in mussels and crabs. No incidents were isolated from cultures of fish in the open seas or cult ures from frozen shrimp. Cultures of marine origin were compared with cultures from hospitalized patients, and these revealed marked serolog ical and toxigenic differences. Marine strains were mainly non-O1 V. c holerae, non toxigenic. We presume fishing off-shore not to be the cau se of this outbreak. However, marine species from contaminated waters could contain toxigenic V. cholerae remaining viable and potentially p athogenic. Methods used were more sensitive and specific for detecting marine strains. In this paper the need to use more specific methods i s discussed.