Epidemiology of Alaria marcianae mesocercariae in Louisiana

Natural infections of Alaria marcianae mesocercariae were detected in five amphibian, seven reptilian, and two mammalian species in Louisiana. Alligators were susceptible to experimental infections with mesocercariae. Natural infections were also found in the subcutaneous fat of raccoons and opossums. Examination of three gravid opossums showed a marked preference of the mesocercariae for the mammary glands, however, we were unable to find transmission of mesocercariae to any of the 27 young. Based on morphological, geographical, and host evidence we believe the etiological agent of the human infection reported by Beaver et al. (1977) to be A. marcianae. Our results emphasize the requirement for precautions when cleaning and eating game animals such as frogs, snakes, alligators, and raccoons.