Prevalence and Associated Risk Factors of Cyclospora cayetanensis in Immunocompromised Patients: A Systematic Review and Meta-Analysis.

Background: Cyclospora cayetanensis, an opportunistic protozoan parasite, poses significant risks to immunocompromised patients, including those with cancer, transplants, or on hemodialysis. The aim of this study was to determine the pooled prevalence of C. cayetanensis in immunocompromised individuals (cancer, transplant, and hemodialysis) and assess the associated risk factors compared to nonimmunocompromised controls. Methods: A comprehensive search of international databases was conducted for studies published up to October 18, 2024, focusing on cross-sectional and case-control studies that reported Cyclospora cayetanensis prevalence in immunocompromised patients. Comprehensive meta-analysis (CMA) software was used to calculate pooled prevalence and odds ratios (ORs), with random-effects models applied to account for heterogeneity based on statistical thresholds. Sensitivity analysis was performed to assess the robustness of pooled prevalence and weighted ORs. Meta-regression analysis was used to evaluate associations between prevalence and variables such as publication year, sample size, and the Human Development Index (HDI). Subgroup analyses were conducted based on geographical regions, publication years, sample sizes, HDI values, income levels, and patient types. This systematic review included 19 studies/22 datasets, comprising 2084 immunocompromised patients and 954 controls across eight countries. Results: The pooled prevalence of C. cayetanensis in immunocompromised patients was 4% (95% CI: 2.1%-7.2%), significantly higher than the 1.2% (95% CI: 0.4%-3.4%) in controls, resulting in an OR of 5.4 (95% CI: 2.6-10.8, p < 0.001). Transplant recipients exhibited the highest pooled prevalence of C. cayetanensis at 5%, indicating the importance of targeted screening and preventive measures for this high-risk group. Conclusions: Despite the relatively low pooled prevalence of C. cayetanensis infection in immunocompromised patients, its notable occurrence compared to controls and its opportunistic nature underscore the need for enhanced surveillance and targeted prevention strategies, especially in high-risk populations and regions with higher exposure.