Prevalence, Genetic Diversity, and Zoonotic Transmission Potential of Cryptosporidium spp. in Snakes: A Systematic...

Cryptosporidium spp. are important protozoan parasites infecting a wide range of vertebrate hosts, including reptiles. In snakes, this parasite is primarily associated with chronic gastrointestinal disease and substantial genetic diversity, including potentially zoonotic species. However, epidemiological data remain fragmented and heterogeneous. Therefore, this systematic review and meta-analysis aimed to evaluate the prevalence, genetic diversity, and zoonotic potential of Cryptosporidium spp. in snakes.

A systematic search was conducted in PubMed, Scopus and Web of Science from database inception to 5 May 2026. Additional studies were identified through Google Scholar and reference screening. Eligible studies reporting Cryptosporidium spp. prevalence in snakes were included. Pooled prevalence estimates and 95% confidence intervals (CIs) were calculated using a random-effects model. Subgroup analyses, sensitivity analysis, meta-regression and publication bias assessment were also performed.

A total of 35 studies comprising 36 datasets were included. The pooled prevalence of Cryptosporidium spp. in snakes was 12.6% (95% CI: 9.2%-17.0%), with substantial heterogeneity (I² = 92.1%). Captive-associated snakes showed higher pooled prevalence (12.7%) than wild/free-ranging snakes (8.7%). Molecular methods yielded higher prevalence estimates than microscopic techniques. Sensitivity analysis demonstrated stable pooled estimates (11.7%-13.6%). Meta-regression showed a significant association between sample size and prevalence, whereas publication year was not significant. Egger's test indicated significant publication bias (p = 0.02). Eight Cryptosporidium species were identified in snakes, including Cryptosporidium serpentis, Cryptosporidium tyzzeri, Cryptosporidium varanii, Cryptosporidium muris, Cryptosporidium parvum, Cryptosporidium baileyi, Cryptosporidium andersoni and Cryptosporidium hominis. The most frequently reported species were C. serpentis, C. tyzzeri, C. varanii, and C. muris. Several zoonotic species, including C. muris, C. parvum, C. tyzzeri, C. baileyi, C. andersoni and C. hominis were detected mostly in captive-associated snakes.

The present study demonstrates that Cryptosporidium infection is relatively common in snakes and exhibits considerable genetic diversity. The detection of zoonotic species highlights the potential epidemiological importance of snakes within a One Health context, particularly in captive-associated environments. However, substantial heterogeneity, limited data from wild populations and incomplete molecular characterization warrant cautious interpretation of the findings. Further large-scale molecular epidemiological studies are needed to better clarify the ecology and zoonotic significance of Cryptosporidium spp. in snakes.