Gastrointestinal helminths in tilapia (Oreochromis niloticus) sold for human consumption in Maiduguri, Nigeria: A potential public health risk

Abstract

Fish is an important and cheap protein source for human consumption in developing countries. It is the second most  popular source of protein diet in both rural and urban communities in Nigeria. Fisheries resources contribute about  5.40% to the nation's gross domestic product (GDP) through income generation, employment, food security, and foreign  exchange earnings. Despite the significant contributions of fisheries to the Nigerian economy, the aquatic  ecosystem is prone to pollution from human activities which increases the chances of transmission of parasitic  infections, which are detrimental to aquatic and human life. The present study assessed the prevalence of gastrointestinal helminths of tilapia fish from different market sources in the Maiduguri metropolitan council of Borno  State, Northeastern Nigeria. Samples of fresh Nile tilapia (Oreochromis niloticus) fish (n= 125), comprising 50 juveniles  and 75 adults, were screened for gastrointestinal helminths using standard parasitological methods. Twenty-nine  (23.2%) harboured at least one helminth parasite. Of the 29 positive individual fish samples, 16% (n=20), 4% (n=5), 2.4%  (n=3), and 0.8% (n=1) were infected by Acanthocephala, Cestode, Nematode, and Trematodes, respectively. The infection rate was higher in adults (26%) than juveniles (18%) and in females (23.5%) than males (22.8%). Fish samples from Baga  markets showed higher infection rates than the other two market sources. Sex, age, and location were not significantly  associated with parasite recovery rate (p>0.05). The study concluded that Nile tilapia fish sold in Maiduguri metropolis  were infected with different groups of helminths, underscoring public health risks to farmers, sellers, and consumers.  Therefore, fish farmers should regularly consult veterinarians for advice on good fish management practices and observe proper hygienic handling of harvested fish at the farm level, during transportation to fish markets, and  processing. The public should thoroughly clean and properly cook fish for human consumption.