Toxoplasma gondii

Ferreira, Susana Carolina Martins, Torelli, Francesca, Klein, Sandra, Fyumagwa, Robert, Karesh, William B., Hofer, Heribert, Seeber, Frank & East, Marion L., 2019, Evidence of high exposure to Toxoplasma gondii in free-ranging and captive African carnivores, International Journal for Parasitology: Parasites and Wildlife 8, pp. 111-117 : 113-114

3.1. Anti-T. gondii antibodies in carnivores in the Serengeti ecosystem

Results from a commercial IHA ELISA revealed that most serum/ plasma samples from spotted hyenas between 1988 and 1992 had anti- T. gondii antibodies, including 6 of 8 samples (75%, CI: 35–97%) from juveniles and 24 of 27 samples (89%, CI: 71–98%) from adults. Results from a commercial ID Screen ª indirect multi-species ELISA for samples from spotted hyenas obtained between 2000 and 2016 revealed that 5 of 11 samples (45%, CI: 17–77%) from juveniles and 14 of 14 samples (100%, CI: 77–100%) from adults had anti- T. gondii antibodies. As we found no significant difference in the results from adults sampled in these two periods (Chi-squared test, χ 2 = 0.44, df = 1, p = 0.51) or for those from juveniles in these two periods (χ 2 = 0.67, df = 1, p = 0.41) we combined the results for adults from the two periods, and the results from juveniles in the two periods. Overall, these combined results revealed that 11 of 19 juvenile (58%, CI: 33–80% %) and 38 of 41 adult (93%, CI: 80–98%) spotted hyenas had anti- T. gondii antibodies. Juveniles were less likely to have anti- T. gondii antibodies than adults (χ 2 = 8.30, df = 1, p = 0.004).

In total we investigated 20 serum samples from adults in three additional carnivore species in the Serengeti ecosystem between 1997 and 2005, using the ID Screen ª indirect multi-species ELISA . The results revealed that all 15 sera (100%, CI: 78–100%) from adult lions and one sample from a striped hyena had anti- T. gondii antibodies whereas sera from four bat-eared foxes were all negative (0% CI: 0–60%). There was no difference in the occurrence of anti- T. gondii antibodies in samples from adult spotted hyenas and adult lions (χ 2 = 0.17, df = 1, p = 0.68).

Results from the ID Screen ª indirect multi-species ELISA for seven samples from captive carnivores (3 spotted hyenas, 3 lions and one brown hyena) in European zoos were all positive ( Tables 1 and 2).

3.2. Comparison of an in-house ELISA assay with a commercial multi-species ELISA

We assessed a total of 48 samples obtained from lions, spotted hyenas and a striped hyena between 2000 and 2016 in the Serengeti ecosystem and from captive lions, spotted hyenas and a brown hyena, for the presence or absence of anti- T. gondii antibodies using the commercial ID Screen ª indirect multi-species ELISA kit and our in-house ELISA . The results in terms of the antibody being detected or not for each of these 48 samples were identical, even though for the commercial ID Screen ª indirect multi-species ELISA we applied a serum dilution of 1:10 whereas for the in-house ELISA we used a serum dilution of 1:100.