The overall prevalence of T. gondii infection in cats in Lanzhou was 21.3%, which was lower than that reported in some other countries, such as in Iran (32.1%) [1, 18], lower than that observed in Guangzhou City (25.2%) , but higher than that in Zhengzhou City (15.5%) and Beijing City (14.1%) in China [19, 20]. The differences in seroprevalences of T. gondii in cats are probably due to differences in ecological and geographical factors, serologic tests used and the living conditions for cats. In general, T. gondii oocysts are more likely to survive in warm and humid environments . The warm and humid climate in southern China (such as Guangzhou) is favorable for the transmission of T. gondii, whereas the cold and dry climate in winter in Lanzhou may be less favorable for the spread of T. gondii.
The results indicated that prevalence of antibodies varied with ages, and T. gondii seroprevalence in older animals was generally higher than that in young animals, however, the differences were not statistically significant (P > 0.05). Female cats had lower prevalence than the male animals, although the difference was not significant (P > 0.05).
In this study, seroprevalence of T. gondii infection in stray cats was 45.2%, which is significantly higher than that (15.6%) in household cats (P < 0.05), consistent with reports from some other countries [21, 22]. Differences in their hunting habits, living conditions and animal welfare may attribute to the difference in T. gondii seroprevalence between household cats and stray cats. Table 2 shows that 20 (42.6%) of the 47 infected cats had anti-T. gondii titers of 1:1600 or higher, indicating that these cats suffered from severe infection and/or repeated exposure to T. gondii, shedding oocysts to the environment.
The present study examined seroprevalence of T. gondii infection in clinically healthy household and stray cats. Further investigations of T. gondii seroprevalence in diseased cats concurrently infected with other feline pathogens are warranted because previous studies have not provided critical evidence to demonstrate association between T. gondii and other feline pathogens .