Prevalence of toxoplasmosis in semi-domesticated and pet cats within and around Bangkok, Thailand

BACKGROUND: Toxoplasmosis is one of the most common parasitic zoonoses worldwide. Cats become infected after ingesting infected tissue cysts. The objective of the present study was to compare the prevalence of toxoplasmosis in pet cats and semi-domesticated cats in the Bangkok metropolitan region. A survey of Toxoplasma infection was conducted in 260 cats (median age [range]: 3 years [10 months–10 years]; 155 females and 105 males) by collecting blood samples from 130 client-owned pet cats and 130 semi-domesticated cats within and around Bangkok during 2016–2017 using indirect fluorescence antibody tests. An IgG antibody to Toxoplasma antigen ratio of ≥1:100 was considered positive for Toxoplasma infection. RESULTS: The overall prevalence of T. gondii in cats was 6.5% (17/260). The prevalence of T. gondii in semi-domesticated cats and pet cats was 11.5 and 1.5%, respectively. Semi-domesticated cats aged 1–5 years (14.9%) had a higher prevalence of infection than domesticated cats (1.3%, p = 0.002) of the same age. The odds (95% confidence interval [CI]) of having T. gondii infection in semi-domesticated cats were 8.34 (1.86–76.29, p = 0.0017) times higher than in pet cats. Interestingly, there was an association between T. gondii infection according to city ​region (p = 0.002). The odds (95% CI) of having T. gondii infection in cats living in the inner city were 4.96 (1.03–47.16, p = 0.023) times higher than cats living in the suburb and the vicinity. CONCLUSIONS: The present study identified a higher prevalence of Toxoplasma infection in semi-domesticated cats compared with pet cats. The semi-domesticated cats could serve as a zoonotic reservoir. Public health regulations should be implemented to prevent toxoplasmosis spread.