Relationship Between Cat Contact and Infection by Toxoplasma gondii in Humans: A Meta-Analysis

摘要

Domestic cats are well known to play an important role in the transmission of infective stages of Toxoplasma gondii to humans and other warm-blooded animals, and it is therefore logical to assume that individuals who own cats would have a higher prevalence of antibodies to T. gondii than would individuals from a normal age-matched population. However, a review of the literature indicates that cat ownership is of variable importance and that it is not always a significant risk factor. The present study was conducted using a meta-analysis to evaluate the relationship between infection by T. gondii and cat ownership. The related literature was searched in multiple literature databases, regardless of language. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the risks of infection by T. gondii. In total, 46 of the 1,813 detected articles were included in our analysis. The risk of infection by T. gondii had a significant association with cat contact (P < 0.05) in the general population, as well as with immunocompromised people, people with special occupations, and cat owners, with ORs (95% CI) of 1.413 (1.163-1.717), 1.558 (1.173-2.069), 1.493 (1.088-2.049), and 1.421 (1.174-1.721), respectively. Interestingly, the risk of infection by T. gondii had no significant association with neighborhood cat contact versus no contact (P = 0.104), with an OR of 1.544 (95% CI: 0.914-2.606), and the proportions of cat ownership in individuals infected and uninfected by T. gondii were not significantly different (P = 0.389), with an OR of 1.375 (95% CI: 0.666-2.840). These data indicate that cat contact can increase the risk of infection by T. gondii in various populations, including the general population, immune-suppressed/pregnant individuals, those with special occupations, and cat(s) owners. Interestingly, the risk of infection by T. gondii has no significant association with neighborhood cat contact versus no contact, and the analysis of the data extracted from a case-control study shows that there is no significant difference in the rate of cat ownership between those infected by T. gondii and those uninfected. Therefore, while significant, cat contact may not be the most important risk factor for infection by T. gondii in cat owners.