When wildlife comes to town: interaction of sylvatic and domestic host animals in transmission of Echinococcus spp. in Namibia.

The present study was conducted in the isolated desert town of Oranjemund in the far south of Namibia. It is an extremely arid region where no livestock husbandry is practiced and only animals adapted to the desert can be found. However, in and around the city, artificial irrigation maintains lush green patches of grass that attract wild animals, in particular oryx antelopes (). In 2015 four oryx antelopes were euthanised due to poor conditions and a post-mortem examination was conducted. Two were found positive for cystic echinococcosis and 16 cysts were collected for molecular analyses. In addition, faecal samples from black-backed jackals (n=5) and domestic dogs (n=9), which were regularly observed to feed on oryx carcasses, were collected and taeniid eggs isolated. Parasite species identification of the cysts and eggs was done by amplifying and sequencing the mitochondrial gene. Both oryx antelopes were found infected with and one co-infected with G6/7. Both species were able to develop fertile cysts in oryx, making oryx antelopes competent hosts for these parasites. Therefore, the analysis of faecal samples was of high interest and although the numbers were quite small, taeniid eggs were found in three out of five faecal samples of jackals and in all nine dog samples. However, species determination was only successful with two jackal and one dog sample. All three were positive for G6/7. The absence of may be due to the low number of faecal samples examined. In our small study, we discovered a rather unique lifecycle of spp. between jackals and domestic dogs as definitive hosts and oryx antelopes as intermediate hosts. Here, the presence of G6/7 is of particular concern, as it is the second most important causative agent of CE in humans.