Transmammary transmission of mesocercariae of Alaria marcianae (Trematoda) in experimentally infected primates.

A lactating primate, Callithrix jacchus, was infected experimentally with 600 mesocercariae of Alaria marcianae 10 days after parturition to determine if she would transmit the mesocercariae to her offspring. Her twin infants were examined 4 wk postinoculation and 16 mesocercariae were found in their tissues. The female was mated again and gave birth to a litter of triplets. She was not given additional mesocercariae. One infant died within hours of birth without suckling and was found negative for any stage of A. marcianae. The other 2 were allowed to nurse for 5 wk, examined and found to be infected with a total of 115 mesocercariae in various tissues, 1 metacercaria in the lungs, and 1 immature and 2 fully formed ovigerous adults in the small intestines. The female was examined at the same time and 246 mesocercariae were recovered. No other stage was found. Histological examination of her mammary glands revealed numerous mesocercariae in the milk-laden alveoli.