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Titre : Ticks and tick-brone diseases in transhumant cattle between Burkina Faso and Republic of Benin : socio-epidemiological aspects

Tiques et maladies associées chez les bovins transhumants entre le Burkina Faso et la République du Bénin : aspects socio-épidémiologiques

Auteur : Zannou, Mahuton Olivier

Université de soutenance : Université de Liège

Grade : Docteur en Sciences Vétérinaires 2021

Résumé partiel
Livestock plays a key role in the macroeconomy of West Africa and provides livelihoods for millions of people. The main cattle rearing strategy in West Africa is pastoralism, including transhumance : i.e. a seasonal migration of cattle with their cattle holders. This adaptive strategy aims to optimize livestock access to water and pastures. However, it can favour pathogens and vectors transboundary spread with many medical and economic consequences to the affected countries. Using a questionnaire survey and statistical modelling, the first study explored the perception of cattle holders about ticks and tick-borne diseases (TTBD) in cattle, their practices in tick control and the social groups involved in cattle farming in eastern Burkina Faso (46 randomly selected herds) and in northern Benin (44 randomly selected herds). Results show that most of the cattle holders (79%) are from the Fulani social group. The principal and secondary activities of cattle holders are respectively cattle farming and agriculture. The mean age of pastoralists is between 40 and 50 years and 60% of the surveyed herds practice internal or transboundary transhumance. Cattle holders have a clear knowledge of different genus of ticks except for the genus Rhipicephalus. Their knowledge of tick-borne diseases (TBD) is very limited. Amitraz appears to be the main acaricide compound used by cattle holders for tick control (68%) but its use is inappropriate and its source is frequently the unregulated market. All of these findings can induce acaricide resistance especially since the inefficacy of amitraz against R. microplus has already been reported in previous studies. Such results would help to elaborate suitable strategies of control and prevention of TTBD in Burkina Faso and Benin. The second study aimed to highlight, firstly the corridors and grazing areas used by Burkina Faso transhumant cattle herds going to Benin, secondly the characteristics of departure and arrival areas of transhumance and thirdly, the risk score related to the introduction and spread of the invasive tick species, Rhipicephalus microplus, in free areas. Therefore, GPS (Global Positioning System) devices were given to 27 cattle holders to monitor a full transhumance season between East Burkina Faso and North Benin. GPS devices revealed four main corridors and five main grazing areas used by cattle herds during transhumance. Normalized Difference Vegetation Index (NDVI) and rainfall are significantly higher in Benin than in Burkina Faso whereas temperature is significantly lower. Additionally, using biotic and abiotic parameters, a risk-scoring model was developed to predict the presence of R. microplus at the municipality level. The invasiveness and adaptability of R. microplus added to the frequent stays of transhumant herds in infested areas suggest its potential introduction and establishment in free areas soon. Moreover, frequent intrusions of the transhumant cattle in the wildlife reserves is another risk of vectors and pathogen exchange between domestic and wild animals.

Mots clés : Ticks ; Epidemiology ; Economic impact ; Habitat suitability ; Tick-borne diseases ; Benin ; Burkina Faso ; Transhumance ; Modelling

Présentation (ORBI)