Echinococcus infections in Colombian animals.

The results of a survey involving more than 4,000 Colombian mammals, carried out to detect Echinococcus infections, are presented. Adult worms were found in 5 of 121 carnivores: E. oligarthrus in 1 of 11 ocelots, 2 of 9 jaguarundi cats and single puma; and E. vogeli in 1 of 15 domestic dogs. Although bush dogs were present, none could be examined. Polycystic larvae were found in 96 of 325 pacas (29.5%) and in 6 of 1,168 (0.5%) spiny rats, Proechimys spp. None of the 118 agouti showed hydatids but an infected heart was provided by hunters. The paca's infection rate increased with age but was not related to sex or geographic region. In 73 of 96 pacas the infection was due to E. vogeli, and the cysts were located in the liver. In 3 it was due to E. oligarthrus and the hydatids were extrahepatic, mainly attached to muscles. In the remaining 20, the species involved could not be determined. The parasites in two of the spiny rats, and in the agouti heart were E. oligarthrus. Although most of the infected animals were collected in the eastern plains, other records and verbal information indicate that, at least in Colombia where man has not exterminated pacas, agoutis, wild canids and felids, one still can find enzootic neotropical Echinococcus infection. The cycle of E. vogeli involves the bush dog and paca as hosts, and that of E. oligarthrus, the paca, agouti, spiny rat, and several species of wild felids.