11/08/2026
Now available in Scientific African
Systematic review and meta-analysis of parasitic infections in clariid catfish (Clarias spp.): African dominance, prevalence trends, and emerging patterns
https://doi.org/10.1016/j.sciaf.2026.e03550
Abstract
Clariid catfish (Clarias spp.) are among the most widely cultured freshwater fish in Africa and Asia, yet consolidated evidence regarding parasitic infections and prevalence trends remains limited. This systematic review and meta-analysis synthesized cross-sectional studies reporting infections in clariid catfish identified through literature searches conducted between 2005 and 2024, with eligible studies published from 2008 to 2024. The review was registered in PROSPERO (CRD420251120588) and conducted in accordance with PRISMA 2020 guidelines. Nineteen eligible studies comprising 2878 examined fish were included. Six major parasite groups were identified, with cestodes, nematodes, and trematodes predominating across regions, whereas acanthocephalans and crustacean ectoparasites were reported infrequently. Mixed helminth infections were frequently reported, particularly in African freshwater systems, reflecting both the strong concentration of studies in Africa and recurrent reports of diverse parasite assemblages in these environments. Protozoan infections were nearly absent from the literature (1/19 studies), and no eligible studies documented bacterial, viral, or fungal prevalence, highlighting substantial gaps in pathogen surveillance. Meta-analysis of comparable datasets involving parasitic helminths and arthropods, while excluding protozoa because of insufficient data, yielded an overall pooled prevalence of 34.7% (95% CI: 24.1–46.0). Cestodes exhibited the highest pooled prevalence (41.2%; 95% CI: 22.2–61.7), followed by nematodes and trematodes, whereas crustacean ectoparasites consistently showed lower prevalence. High between-study heterogeneity (I² > 96%) reflected substantial geographic, ecological, and methodological variability. These findings highlight the strong African concentration of the available evidence base, substantial heterogeneity in reported prevalence that precludes simple generalizations across studies, and important gaps in pathogen surveillance, particularly for protozoan, bacterial, viral, and fungal infections. Strengthening parasite surveillance and integrated health management strategies will be essential for improving fish health, aquaculture productivity, and food security in Africa and other regions practicing clariid aquaculture.