Prevalence of Feline Immunodeficiency Virus and Toxoplasma gondii in Feral Cats on St. Kitts, West Indies

Abstract

Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite that infects all warm-blooded species including humans. The definitive hosts of T. gondii are felid vertebrates including the domestic cat. Domestic cats shed oocysts for approximately two weeks in their feces after the primary infection. It has been shown that feline immunodeficiency virus (FIV) positive cats have a higher prevalence of and a higher titer of antibodies to T. gondii than those of FIV-negative cats. The main purposes of this study were to determine FIV prevalence and to investigate the oocysts shedding in FIV-positive and FIV-negative feral cats on St. Kitts. Fecal samples were collected from feral cats while their FIV statues were determined using a commercial SNAP kit. Total fecal DNA of each cat was tested for the presence of T. gondii DNA using a polymerase chain reaction (PCR) consistently detecting one genome equivalent. A FIV-positive status was detected in 18 of 105 (17.1%, 95% confidence interval (CI): 9.9%−24.3%) feral cats sampled. Furthermore, males were three times more likely to be FIV positive than females (p = 0.017) with an odds ratio of 3.93 (95% CI: 1.20–12.89). Adults were found to have at least twice the prevalence of FIV compared to cats younger than one year of age (p = 0.056) with an odds ratio of 3.07 (95% CI: 0.94–10.00). Toxoplasma gondii DNA was not detected in the feces of any of the 18 FIV-positive (95% CI: 0%−0.18%) and 87 FIV-negative cats (95% CI: 0%−0.04%). A follow-up study with a much bigger sample size is needed to prove or disprove the hypothesis that FIV-positive cats have a higher prevalence of shedding T. gondii oocysts than FIV-negative cats.

Description of Babesia galileei sp. nov. A piroplasmid species causing severe disease in domestic cats

“…Co-infection with the immunosuppressive virus FIV in cat # 1 may have played a role in increasing its susceptibility to becoming infected or to progressing from infection to clinical disease. Associations between parasitic infections and FIV in populations of domestic cats have been reported previously and include an association between FIV and Leishmania infantum infection and a relationship between FIV and Toxoplasma gondii seropositivity [ 44 , 45 ]. The immunosuppressive therapy that cat # 2 received with prednisolone and cyclosporine because of suspected IMHA probably contributed to the development of babesiosis in this cat, as the cat was ill before the immunosuppressive treatment began but Babesia organisms were detected in its blood smears only after cyclosporine treatment was begun.…”

Serological and molecular survey of Toxoplasma gondii infection and associated risk factors in urban cats in Kunming, Southwest China

“…The seroprevalence of T. gondii infection in cats was as high as 41.4%, whereas the DNA positivity rate was 0% ( 14 ). It is generally believed that the definitive host sheds oocysts for about 2 weeks at the time of initial infection and thereafter no longer sheds oocysts upon secondary infections, due to long-term immunization preventing oocyst shedding ( 29 , 30 ). Therefore, seropositivity of T. gondii does not mean that the cat is excreting oocysts, which requires further measurement by PCR ( 30 , 31 ).…”

A comprehensive review of viruses in terrestrial animals from the Caribbean islands of Greater and Lesser Antilles

“…In Grenada, antibodies to FIV have been reported in 11.8–19% of sampled feral cats and 6% of sampled domestic cats (Dubey et al., 2009; Miller et al., 2017). St. Kitts and Nevis reported seroprevalence rates of 14–17.1% in sampled stray cats (Chi et al., 2021; Kelly et al., 2010). In a 2011 study from St. Kitts, 4 of 11 stray cats (36 %) tested positive for FIV subtype‐B by quantitative fluorescence resonance energy transfer (FRET) PCR assay (Kelly et al., 2011).…”