OUTBREAK OF VIBRIO-CHOLERAE O1 IN HONG-KONG RELATED TO CONTAMINATED FISH TANK WATER

An outbreak of 12 cholera cases, caused by Vibrio cholerae eltor inaba , occurred in Hong Kong during a three week period in June-July 1994. Only adults of both sexes were affected. Epidemiological investigation s showed linkage in all cases with consumption of seafood, including s hellfish, mantis shrimps and crabs. Microbiological findings demonstra ted that contaminated seawater in fish tanks used for keeping alive th ese seafoods is the most likely vehicle of transmission. Aggressive co ntrol measures, promptly instituted, included prohibition of use of co ntaminated typhoon shelter water in fish tanks, use of seawater with E . coli counts below 610 organisms/100 ml, and the banning of unlicense d food sampans in typhoon shelters. These measures, coupled with publi c announcements and an active health education campaign on food safety and personal hygiene, abruptly terminated the outbreak. Places which practise the use of seawater. from probable contaminated sources, to k eep alive their seafood for human consumption should be alerted to the possibility of transmission of Vibrio cholerae through this route.