Echinococcus vogeli in man, with a review of polycystic hydatid disease in Colombia and neighboring countries
D'Alessandro, A.; Rausch, R.L.; Cuello, C.; Aristizabal, N.
American Journal of Tropical Medicine and Hygiene 28(2): 303-317
1979
ISSN/ISBN: 0002-9637 PMID: 572148 Document Number: 139831
Three cases of polycystic hydatid disease (PHD) from Colombia are reported and 11 others from the region are reviewed. When cysts from 2 patients were fed to a dog and an ocelot about 250 mature and gravid specimens of Echinococcus vogeli and 2 poorly developed strobilae, respectively, were recovered. These human cases constitute the first record of the larval stage of E. vogeli, previously known only from the strobilar stage in the type host, the bush dog (Speothos venaticus). Based on the morphological characteristics of the protoscolex rostellar hooks from other PHD cases (6 Colombian, one Ecuadorian, and one Panamanian), it is concluded that all were also due to E. vogeli, rather than to E. oligarthrus as was previously suggested. Although E. oligarthrus is or may be present in the same areas, so far no human infection with this parasite has been confirmed. Of the 14 cases reported, 13 were pathologically proven to be PHD. Clinically, 8 had an undiagnosed tumour-like mass in or near the liver, one had a subcutaneous mass in the anterior 6th intercostal space, and in 2 the cysts were in the chest. 2 were autopsy findings. In contrast to E. multilocularis, the cysts produced by E. vogeli were found to be relatively large and filled with fluid; brood capsules and protoscoleces were numerous. Focal necrosis was commonly observed but large necrotic cavities were not seen. The main natural intermediate host is the paca (Cuniculus paca); man probably obtains the infection by contamination from faeces of infected hunting dogs. [AS].