Ascaridia galli and Heterakis gallinarum prevalence and genetic variance of A. galli in rural chicken from the Northern Region, Ghana

Rural chicken production in Ghana is predominantly done under the extensive system that exposes birds to parasitic infections. We investigated the prevalence of Ascaridia spp. and Heterakis spp. and as a preliminary study characterized the genetic variance of the Ascaridia galli isolates from rural chicken in Kumbungu, Savelugu and Tolon Districts in the Northern Region, Ghana. A total of 86 chickens aged 6-10 weeks were dissected and GIT inspected for nematodes. Nematode were described based on morphological features to be A. galli and H. gallinarum. Additionally, the mitochondrial cox1 gene (475 bp) of Ascaridia isolates was amplified and sequenced. The overall prevalence of nematodes was 47.67%: A. galli 37.21% and H. gallinarum 20.93%. Prevalence values of A. galli in the Kumbungu, Savelugu and Tolon Districts were 25.00%, 36.00%, 56.00%, respectively, and that of H. gallinarum, respectively were 16.67%, 28.00% and 20.00%. A Chi-square test (x² = 6.0907, p < 0.048) showed an association of A. galli prevalence to the district of origin of birds. From 20 A. galli cox1 sequences analyzed, all sequences were identified as A. galli. Two haplotypes were recorded, namely, GHA1 and GHA2. Haplotype GHA1 was found to have wide distribution globally, whereas GHA2 appear to be novel in the present study. The data shows the importance of A. galli and H. gallinarum infection in rural chicken in northern Ghana and pave way for further epidemiological study of avian nematodes.