Seroepidemiology and risk assessment of Toxoplasma gondii infection in captive wild birds and mammals in two zoos in the North of Portugal

- Toxoplasmosis in captive wildlife may endanger species at risk of extinction.
- We describe Toxoplasma gondii seroprevalence in captive wild animals in Portugal.
- An overall 34.5% prevalence of T. gondii infection was found in zoo animals, i.e. 77 birds and 42 mammals.
- Results show a considerable exposure of zoo animals to the parasite in the country.
- Staff and people visiting zoos can be exposed to zoonotic T. gondii infections.

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is one of the most widespread zoonoses in the world. It can affect most warm-blooded animals but only felids are its definitive hosts. We determined seroprevalence and associated risk factors in birds and mammals kept in two zoological parks in northern Portugal. Sera from 77 birds and 42 mammals were assayed for the presence of T. gondii antibodies by the modified agglutination test (MAT, cut-off titre 20); 34.5% (41/119) were seropositive. All seropositive animals were apparently healthy except one seropostive mandarin (Aix galericulata) which had chorioretinitis. This is the first report on T. gondii seroprevalence in wild animals in captivity in Portugal. The present findings indicate a widespread exposure of zoo animals in Portugal to T. gondii.