Ortwin Aschenborn (Stuttgart / DE; Berlin / DE; Windhoek / NA), Piet Beytell (Windhoek / NA), Joerg Melzheimer (Berlin / DE), Ute Mackenstedt (Stuttgart / DE), Thomas Romig (Stuttgart / DE), Marion Wassermann (Stuttgart / DE)
Abstract text
Introduction: Cystic Echinococcosis is a worldwide occurring zoonotic disease and can be caused by five distinct species of the cestode genus Echinococcus. Only in Africa are all five species present. Whereas E. felidis was so far only be found in wildlife, the lifecycle of the four other species, E. granulosus sensu stricto (s.s.), E. ortleppi, E. canadensis (G6/7) and E. equinus, is clearly associated with various livestock species and domestic dogs. However, previous studies showed that some of those domestic Echinococcus species can also be found in wild animals, e.g. E. granulosus s.s. in Kenyan lions. There is, however, little known about the extent to which wild animals are involved in the different lifecycles and their maintenance.
Objective: The present study was conducted to learn more about the situation of Echinococcus spp. in wildlife in Namibia.
Material & Methods: At various locations in Namibia, faecal samples were collected from 224 wild carnivores and examined for the presence of taeniid eggs, and 300 possible wild intermediate hosts were examined for the presence of cysts. For species identification, eggs and cysts were analysed by PCR and sequencing of the nad1 or cox1 gene.
Results: Echinococcus spp. could be identified in 31 carnivorous and 39 intermediate hosts. As anticipated, the wildlife adapted E. felidis could be detected in lions (7) and warthogs (4). However, the livestock associated species were also present. Echinococcus granulosus s.s. was found in African wild dog (2), E. ortleppi in black-backed jackals (2) and oryx antelopes (6) and E. equinus in lions (9), black-backed jackals (2) and zebras (27). The Echinococcus species detected in the most wildlife species was E. canadensis G6/7, namely in lions (3), cheetahs (3), African wild dogs (1), black-backed jackals (2) and oryx antelopes (2).
Conclusion: All five Echinococcus species have been detected in Namibian wildlife, although only E. ortleppiand E. canadensis G6/7 have been found so far in Namibian cattle and sheep, respectively. These results indicate that the presence of Echinococcus spp. in wildlife is not accidental, but wild animals are important links in the parasitic lifecycle, at lease in the study area.