Abstract:
A systematic review and meta-analysis were conducted, and published estimates determined the
pooled prevalence of gastrointestinal nematode parasites affecting free-ranging chickens in
Africa. Peer-reviewed articles published between 1993 and 2024 were systematically searched
and screened. Prevalence estimates based on 76 eligible articles showed that of the 74,789 freeranging
chickens screened, 13,625 were infected with gastrointestinal nematodes with an overall
pooled prevalence of 15% (95% CI: 13–18%). Twenty-seven nematode species were recorded, of
which Ascaridia galli and Heterakis gallinarum were the commonly reported species. Southern
Africa recorded the highest pooled prevalence (22%; 95% CI: 13–33%), and western Africa had
the lowest (5%; 95% CI: 0–2%) despite recording the highest nematode species diversity.
Tetrameridae had the highest family-level pooled prevalence of 46% (95% CI: 28–64%), and
Spiruridae had the lowest 1% (95% CI: 0–3%). Most studies were conducted between the period
2014 and 2024; however, the highest pooled prevalence was observed between 1993 and 2002
(17%; 95% CI: 11–24%). The necropsy technique recorded the highest pooled prevalence (17%;
95% CI: 14–20%) compared to coproscopy (10%; 95% CI: 7–14%). The quality effects model
revealed a high heterogeneity and publication bias among studies due to the diagnostic method
used (P <0.05). This systematic review provided insightful information on the occurrence and
potential burden of gastrointestinal nematode species of free-ranging chickens in Africa,
highlighting the need for enhanced biosecurity and further research to safeguard their health,
production, and food security of rural economies.
