Systematic Review and Meta-analysis of Role of Felids as Intermediate Hosts in the Life Cycle of Neospora caninum Based on Serological Data

Purpose

Neosporosis is an important widespread parasitic infection caused by N. caninum. It infects a wide range of warm-blooded animals as intermediate hosts and dogs as the definitive host. Nevertheless, there are a number of questions regarding the life cycle and epidemiological aspects of N. caninum. Also, the role of felids (domestic and non-domestic) in the life cycle of N. caninum has been little described. Therefore, this study was conducted to evaluate the global prevalence of N. caninum in domestic and wild felids.

Methods

PubMed, Scopus, Google Scholar, Web of Science, and ScienceDirect databases were searched for articles published on the prevalence of N. caninum in felids until Aprill 2, 2022 and the reference lists of retrieved articles were screened. A random-effects meta-analysis model was used to estimate the pooled prevalence and 95% confidence interval. Heterogeneity among studies was evaluated using Cochran’s Q and the I² statistic.

Results

After exclusion of irrelevant articles and duplication removal, 30 studies were eligible for quantitative analysis including 20 studies on domestic cats and 10 studies on wild felids. The overall prevalence of neosporosis infection in cats was 15% (95% CI 10–21%) that was significantly higher in wild felids (26%, 95% CI 13–38%) than in domestic cats (11%, 95% CI 6–16%) (P = 0.03). There was no significant difference in pooled prevalence between male and female domestic cats (P = 0.75). Regarding continent, the lowest prevalence of neosporosis infection was in Asia (9%, 95% CI 1–20%) and the highest was in North America (43.6%, 95% CI 33.9–53.2%) and Africa (18%, 95% CI 9–46%). Higher prevalence was obtained when using the NAT with 22% (95% CI 7–37%), compared to the IFAT (17%, 95% CI 9–24%) and ELISA (6%, 95% CI 2–9%) (P = 0.01).

Conclusion

The findings highlighted the importance of felids as potential intermediate hosts of neosporosis despite the fact that the source of the parasite for these animals was unknown. Further studies should be performed to investigate the role of this top predator (felids) in maintaining both domestic and sylvatic cycles of Neospora caninum.