Impact of herd mobility on brucellosis seroprevalence and spread risk resulting from cross-border transhumance

Vet Med Sci. 2024 May;10(3):e1446. doi: 10.1002/vms3.1446.

Abstract

Background: Cross-border livestock mobility through transhumance is mainly practiced in West African countries for seasonal access to resources and market. Cross-border herds are involved in the dynamic of transboundary animal diseases among them brucellosis taken as model. Brucellosis is a zoonotic disease causing abortion.

Objectives: This study explores the seroprevalence of brucellosis according to mobility and infection spread between Mali and Côte d'Ivoire in the context of seasonal cross-border transhumance.

Methods: From February to April 2021, a transversal serological survey of brucellosis was conducted on 521 cattle from 111 transhumant herds and 283 cattle from 59 sedentary herds, all from Mali.

Results: The global individual seroprevalence for Brucella spp. in transhumant and sedentary cattle from Mali was 8.2% (95% CI = 6.0-10.5). At herd level, seroprevalence was 21.2% with a significant variation between transhumant (11.7%) and sedentary (39.0%) herds. For herds in transhumance, cattle seropositivity was associated with a previous infection suspected by herdsmen odds ratio (OR = 4.4; 95% CI = 1.1-18.1) and unknown abortion aetiology (OR = 4.3; 95% CI = 1.0-17.3). The departure region (coming from Sikasso) and previous brucellosis infection or unexplained abortion could be used to predict Brucella infection in transhumant herds with a probability of around 60%. The risk of brucellosis introduction in host regions was high despite the individual animal seroprevalence of 3.6% and a low sale rate in transhumant cattle.

Conclusions: The findings suggest that testing transhumant during border control and survey of cattle markets and sales could improve risk control of the spread of disease at regional scale.

Keywords: Mali; brucellosis; cattle; sedentary; transhumance.

MeSH terms

  • Animals
  • Brucella*
  • Brucellosis* / epidemiology
  • Brucellosis* / veterinary
  • Cattle
  • Female
  • Pregnancy
  • Risk Factors
  • Seroepidemiologic Studies
  • Zoonoses