Authors

Discussion

Toxoplasmosis, a zoonosis caused by the protozoan Toxoplasma gondii, represents an important challenge to unique health, since it infects a wide variety of homeothermic hosts, such as domestic and wild mammals, including humans. Due to its wide distribution and increasing environmental fragmentation, T. gondii assumes relevance in anthropized ecosystems, being responsible for causing outbreaks, especially in neotropical primates. The howler monkey (Alouatta. guariba) are neotropical primates, widely distributed in the Atlantic Forest of Brazil, which have arboreal habits and play an essential ecological role in the maintenance of the forest due to seed dispersal. The species is highly susceptible to infection by T. gondii, and can develop severe clinical conditions and die, even before the production of antibodies, which reinforces the importance of studies focused on population health and conservation. The present study aimed to investigate the occurrence of antibodies and perform the molecular detection of T. gondii in  free-living and captive howler monkeys in the state of Santa Catarina, Brazil. Sera from 86 individuals were analysed by the Modified Agglutination Test (MAT ≥25), of which only one animal (1.16%) was positive, with a titre of 1:800. At the same time, DNA was extracted from tissue fragments (brain, heart, lung and spleen) of 41 individuals, totalling 164 samples, submitted to molecular detection by polymerase chain reaction (PCR - fragment 529 bp), presenting three (7.31%) positive animals, one positive in heart, lung and spleen, and two in lung and spleen. All brain samples were negative for the presence of T. gondii DNA. The low occurrence of anti-T. gondii antibodies observed may possibly be related to the high susceptibility of the species and the early death of infected animals before the development of a detectable immune response. The combination of serological and molecular methods proved to be important for the monitoring of T. gondii infection, contributing to a better understanding of the dynamics of parasite transmission in neotropical primates, as well as to the monitoring of risks from the perspective of One Health.