Helminth parasites of farmed fish and water birds in Kirinyaga County, Kenya

Abstract

Aquaculture products demand has increased due to population growth, declining natural fish stocks and government aquaculture promotion. Intensification alters natural fish environment and new infections emerge. Parasite infested fish are unaesthetic. Public health concerns arise with zoonotic fish parasites. Piscivorous birds influence aquaculture profitability due to predation and transmission of fish parasites. 289 fish from 15 private farms and one government farm were sampled in Kirinyaga County, Kenya. Earthen pond fish had higher (52%) parasite infestation than those from liner (7%) and concrete ponds. Fish parasites recovered were Diplostomum spp. (tilapia 21.7%; catfish 10.5%), Acanthocephala spp. (tilapia 11.3%; catfish 3.5%), Dactylogyrus spp. (tilapia 3%; catfish 4.7%) Contracaecum (catfish 24.4%), Paracamallanus spp. (catfish 16.3%) Gyrodactylus spp. (catfish 5.8%) and Clinostomum spp. (tilapia 4.9%). Fifty water birds were captured using mist nets. On necropsy, 46% were infected with parasites like Acanthocephala spp. (16%), Pseudophyllid and Protecephallid cestodes (36%) Contracaecum spp. (2%) and Clinostomum spp. (2%). Clinostomum spp., Contracaecum spp. and Acanthocephala spp. are zoonotic. Farmers, traders and consumers should be advised on handling and cooking fish to avoid infestation with zoonotic parasites. Control of piscivorous birds and other predators should be effected to maximize the profitability of fish farming.