Global Prevalence of Chlamydial Infections in Reptiles: A Systematic Review and Meta-Analysis

Background and Objectives:Chlamydiaspp. are potential zoonotic pathogens that can infect a wide range of animal hosts. In reptiles,Chlamydiacan cause hepatitis, pneumonitis, and conjunctivitis and it can cause high mortality in young animals. The objectives of this study were to estimate the pooled prevalence of chlamydial infections in reptiles and to assess the trend of these infections over time. Materials and Methods:The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant studies were retrieved from PubMed, Scopus, and Web of Science. The retrieved studies were screened for eligibility. Then, important data were extracted from the included studies. A random effects model was used for all analyses. Subgroup analysis was used to assess heterogeneity for orders of reptiles, continents where the studies were conducted, and types of specimens. Cumulative meta-analysis and meta-regression were used to determine the trend of the prevalence over time. The quality of each included study was evaluated. Results:Of 106 studies (with a total of 2607 samples), 20 met the inclusion criteria and were included in the meta-analysis. The pooled prevalence of chlamydial infections in reptiles was 23.5% (95% confidence interval [CI]: 15.4-34.0). The trend of chlamydial infections increased from 1990 to 2008; thereafter, it was almost stable at slightly over 20%. The most commonly reportedChlamydiaspp. wereChlamydia psittaci,Chlamydia pneumoniae,Chlamydia pecorum, andChlamydia caviae. Among reptiles, the prevalence of chlamydial infections was highest in crocodiles (57.3% [95% CI: 32.5-78.9]). Among continents, the prevalence of chlamydial infections was highest in Australia (68.6% [95% CI: 36.8-89.1]). Conclusions:Based on the included studies, the prevalence of chlamydial infections in reptiles was high, especially in crocodiles. BecauseC. psittaci and C. pneumoniaeare commonly found in reptiles and are well-known zoonotic pathogens, they should be of concern for human health.