Just published: our seroprevalence paper on apicomplexan parasites in Namibian wildlife

We are glad to communicate that our seroprevalence paper on apicomplexan parasites was published yesterday. In this work, we tested more than 500 individuals of 12 wildlife species sampled on Namibian farmland and National Parks. The main results are that seroprevalence of apicomplexan parasites in carnivores ranged between 52% in cheetahs and 93% in lions (and 92% in brown hyenas). We also show that older individuals have higher Toxoplasma infections than younger ones.

Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites (Toxoplasma gondiiNeospora caninum and Besnoitia besnoiti) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs (Acinonyx jubatusn = 250) and leopards (Panthera pardusn = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group) and site (natural habitat vs farmland).

All but one carnivore species (bat-eared fox Otocyon megalotisn = 4) were seropositive to T. gondii, with a seroprevalence ranging from 52.4% (131/250) in cheetahs to 93.2% (55/59) in African lions (Panthera leo). We also detected antibodies to T. gondii in 10.0% (2/20) of blue wildebeest (Connochaetes taurinus). Adult cheetahs and leopards were more likely to be seropositive to T. gondii than subadult conspecifics, whereas seroprevalence did not vary with sex, sociality and site. Furthermore, we measured antibodies to N. caninum in 15.4% (2/13) of brown hyenas (Hyaena brunnea) and 2.6% (1/39) of black-backed jackals (Canis mesomelas). Antibodies to B. besnoiti were detected in 3.4% (2/59) of African lions and 20.0% (4/20) of blue wildebeest.

Our results demonstrate that Namibian wildlife species were exposed to apicomplexan parasites at different prevalences, depending on parasite and host species. In addition to serological work, molecular work is also needed to better understand the sylvatic cycle and the clear role of wildlife in the epidemiology of these parasites in southern Africa.

The article can be freely downloaded and accessed here:

https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-019-3871-3?fbclid=IwAR3H5LVeu2uGLqSLvX7T93eL1K4Ra8BGOoUfrj6u09d3I8VxiSCt7kUMhkc