Toxoplasmosis in cats in northeastern Brazil: Frequency, associated factors and coinfection with Neospora caninum, feline immunodeficiency virus and feline leukemia virus

The aim of this study was to determine the frequency and the factors associated with infection by Toxoplasma gondii and demonstrate occurrences of coinfection with Neospora caninum, the feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) in cats in the state of Bahia, Brazil. A total of 231 blood samples were collected from 201 owned cats and 30 stray cats. Serological investigations on T. gondii and N. caninum were performed using the indirect fluorescent antibody test with cutoff points of 1:64 and 1:50, respectively. To diagnose FIV and FeLV, a commercial immunochromatographic kit and a nested polymerase chain reaction (PCR) was used. Unconditional logistic regression was performed to assess the factors associated with infection by T. gondii among owned cats. The seropositivity for T. gondii among the owned cats and stray cats was 44.3% (89/201) and 53.3% (16/30), respectively. For N. caninum, the seropositivity among owned cats was 21.4% (43/201) and among stray cats, 23.3% (7/30). The copositivity between the two coccidia were 23.6% (21/201) and 37.5% (6/30), among owned and stray cats respectively. The periurban environment was a risk factor for infection by T. gondii, while infection by FIV was associated with infection by T. gondii (p<0.05) among owned cats. No association was found between T. gondii and FeLV, or between N. caninum and the retroviruses. Based on these results, it can be concluded that the cats of the present study were exposed to the agents T. gondii and N. caninum, which suggests that significant infection of intermediate hosts and or environmental contamination with oocysts was present, and that the cats coinfected with T. gondii and the retroviruses did not present any serological signs of reactivation of infection.