TRACKING A SALMONELLA SEROVAR TYPHIMURIUM OUTBREAK IN GIDEON, MISSOURI - ROLE OF CONTAMINANT PROPAGATION MODELING

In early December of 1993, a waterborne disease outbreak was identifie d in Gideon, Missouri (USA). Initially 6-9 cases of diarrhoea were ide ntified at a local nursing home. By 8 January 1994, 31 cases with labo ratory confirmed salmonellosis had been identified. Seven nursing home residents exhibiting diarrhoeal illness died, four of whom were cultu re confirmed. It was estimated that approximate to 44% of the 1104 res idents, or almost 600 people, were affected with diarrhoea between 11 November and 27 December 1993. A system evaluation was conducted in wh ich a computer model (EPANET) was used to develop scenarios, to explai n possible contaminant transport in the Gideon system. It was conclude d, based on this analysis, that the outbreak resulted from bird contam ination in a municipal water storage tank.