Internal parasitic helminth infecting reared fishes from the West Region of Cameroon: Epidemiological profile and effects on fish health

Abstract

Intensification of the fish farming sector in Cameroon can result to reduction of profitability and public health concerns due to emergence of parasites amongst which zoonotic ones. Unfortunately, limited and outdated data are available on internal parasites of reared fish as well as their impact on the infected fish. A total of 2254 live fish samples of males and females were randomly obtained made up of Clarias gariepinus (692), Cyprinus carpio (593) and Oreochromis niloticus (969). The skin, the gastrointestinal tract of the fish was examined for the presence of parasite, using standard procedures. An overall prevalence of 8.47% coupled with a very low intensity was assessed. This study revealed a diverse parasitic fauna made up of Acanthocephala sp. (4.84%), Cappilaria sp. (1.91%), Eustrongylides sp. (1.06%), Camallanus sp. (1.2%) and Orientatractis sp. (0.34%). Meanwhile, intensities mean values were higher in Cappilaria sp. followed by Eustrongyloides sp., Camallanus sp. and finally Acanthocephalus sp. Prevalence of internal parasites was higher in Cyprinus carpio (8.77%). Clarias Gariepinus on the other hand, had a higher intensity. Fish were mostly infected during the dry season. Nevertheless, a high parasitic load was observed in the rainy season. Specimens collected in the earthen ponds show a higher prevalence (p < 0.05), while those in concrete ponds had a higher infection intensity. Females were more prevalent contrary to males which have a higher intensity. Parasites were identified from the body cavities and gastrointestinal tracts of fishes. Comparison of Length/Weight relationship and Fulton condition index K does not show any differences between the parasitized and non-parasitized specimens. Parasites with a zoonotic potential were detected in this study, highlighting the importance of intensifying biosecurity and parasite control measures in fish farms in West Cameroon.