AVIAN BOTULISM - ANOTHER PERSPECTIVE

Waterfowl botulism is unique among intoxications because toxin produce d within its victims leads to secondary poisoning of other birds. Beca use of this phenomenon, the epizootiology of the carcass-maggot cycle of botulism resembles that of an infectious disease and the reproducti ve rate (R) of the disease could be defined as the average number of s econdary intoxications attributable to a single carcass introduced int o a marsh. I propose that toxin production and botulism occur commonly at a low level in many marshes and that factors which influence R det ermine when the disease expands into a large epizootic. A model that i ncorporates the number of carcasses occurring in a marsh, the probabil ity of a carcass containing spores, the probability of a carcass persi sting until toxin-bearing maggots emerge, and the contact rate between live birds and toxin, may be useful for predicting the extent of seco ndary poisoning, for identifying questions for research, and as a theo retical basis for management.