Future climate change is projected to predominantly suppress the transmission potential of the small ruminant parasite Haemonchus contortus in Africa
Year: 2025
Type: article
Abstract: • Haemonchus contortus transmission potential is projected to decline under climate change during the typical transmission seasons across most African subregions. • Localised increases in transmission potential are also anticipated, particularly in January to March and December in the Atlas subregion and intermittently in high-elevation, topographically complex and coastal areas. • Climate change is unlikely to alter transmission season length across most of Africa, though shorter seasons are projected in southern East Africa, the Gulf of Guinea and the Eastern Sahel, with a new transmission window emerging in August in western Southern Africa. • Even where transmission potential decreases, in most cases conditions will remain conducive to transmission, emphasising the continued need for regular monitoring and targeted control of haemonchosis. This paper examines the impact of climate change in Africa on the transmission potential ( Q 0 ) of Haemonchus contortus ( H. contortus ), a highly pathogenic haematophagous gastrointestinal nematode (GIN) parasite that has significant implications for the health and productivity of small ruminants. Changes in Q 0 were assessed over the period 1981–2070 under a high emission scenario (RCP 8.5). Climate data was sourced from bias-adjusted Coordinated Regional Climate Downscaling Experiment (CORDEX) models for Africa, which was split into 13 subregions based on areas within each having approximately similar rainfall seasons, which also defines typical periods of H. contortus transmission in Africa. Results indicate that while the transmission potential of H. contortus may increase in the Atlas region, topographically complex, high-elevation and coastal areas, Q 0 is more widely projected to decrease across much of Africa. While climate change is not expected to alter the length of the transmission season in most areas of Africa, shorter transmission periods are expected in southern East Africa, the Gulf of Guinea, and the Eastern Sahel, while new periods of transmission are projected to occur in western Southern Africa. Future research should focus on optimising the model for Africa and developing a decision-support tool for farmers, advisors and animal health services that classifies Q 0 by hazard severity and provides tailored management recommendations for each category.
Authors: J.H.I. Tinsley, E.R. Morgan
Institution: Queen's University Belfast
Language: English
Subfield: Small Animals
Field: Veterinary
Domain: Health Sciences
SDGs: Climate action, Zero hunger
Open Access status: hybrid
Estimated APC paid: $2,880
OpenAlex ID: W4413824926