Exploring the role of mesocarnivores and predatory birds in the circulation of Trichinella (Nematoda) in South Africa.

Abstract

The genus Trichinella encompasses several species of parasitic nematodes that are of significant zoonotic and One Health relevance. Despite this importance, knowledge gaps remain in their distribution and genetic relationships, making biodiverse regions like South Africa important areas for research. To date, three Trichinella species have been identified in naturally infected hosts from this region: T. nelsoni, Trichinella T8, and T. zimbabwensis. However, knowledge of their life cycle, host diversity, and genotypic variation in the sylvatic cycle is limited. Between 2016 and 2018, 175 muscle samples from11 mammalian and six bird families, were examined using the artificial digestion method for Trichinella larvae to assess the role of synanthropic and sylvatic mesocarnivores and predatory birds in Trichinella epidemiology. The obtained isolates were further analyzed through PCR and sequencing analyses. Larvae were detected in five individuals (4 %)of the 125 mammals sampled; representing four species from the order Carnivora: the bat-eared fox (Otocyon megalotis), black-backed jackal (Canis mesomelas), marsh mongoose (Atilax paludinosus), and domestic cat (Felis catus). Of the 50 bird samples only one white-browed coucal (Centropus superciliosus burchellii) was infected (2 %). Molecular analyses confirmed T. nelsoni in the black-backed jackal and marsh mongoose, and Trichinella T8 in the black-backed jackal, with inconclusive results in isolates from the domestic cat, bat-eared fox, and white-browed coucal. The infected marsh mongoose represents a new host record for T. nelsoni. The detection of unidentified Trichinella-like larvae in the white-browed coucal emphasizes the need for further research to determine which Trichinella species are circulating among bird populations in Africa and to assess the extent of their presence.