High Prevalence of Bovine Tuberculosis in Dairy Cattle in Central EthiopiaImplications for the Dairy Industry and Public Health

Authors Organisations
  • Rebuma Firdessa(Author)
    Armauer Hansen Research Institute
    University of Würzburg
  • Rea Tschopp(Author)
    Armauer Hansen Research Institute
    Imperial College London
    Swiss Tropical Institute
  • Alehegne Wubete(Author)
    National Animal Health Diagnostic and Investigation Center
  • Melaku Sombo(Author)
    National Animal Health Diagnostic and Investigation Center
  • Elena Hailu(Author)
    Armauer Hansen Research Institute
  • Girume Erenso(Author)
    Armauer Hansen Research Institute
  • Teklu Kiros(Author)
    Armauer Hansen Research Institute
  • Lawrence Yamuah(Author)
    Armauer Hansen Research Institute
  • Martin Vordermeier(Author)
    Animal and Plant Health Agency
  • Glyn Hewinson(Author)
    Animal and Plant Health Agency
  • Douglas Young(Author)
    Imperial College London
  • Stephen V. Gordon(Author)
    University College Dublin
  • Mesfin Sahile(Author)
    National Animal Health Diagnostic and Investigation Center
  • Abraham Aseffa(Author)
    Armauer Hansen Research Institute
  • Stefan Berg(Author)
    Animal and Plant Health Agency
Type Article
Original languageEnglish
Article numbere52851
JournalPLoS One
Volume7
Issue number12
DOI
Publication statusPublished - 28 Dec 2012
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Abstract

Background: Ethiopia has the largest cattle population in Africa. The vast majority of the national herd is of indigenous zebu cattle maintained in rural areas under extensive husbandry systems. However, in response to the increasing demand for milk products and the Ethiopian government's efforts to improve productivity in the livestock sector, recent years have seen increased intensive husbandry settings holding exotic and cross breeds. This drive for increased productivity is however threatened by animal diseases that thrive under intensive settings, such as bovine tuberculosis (BTB), a disease that is already endemic in Ethiopia. Methodology/Principal Findings: An extensive study was conducted to: estimate the prevalence of BTB in intensive dairy farms in central Ethiopia; identify associated risk factors; and characterize circulating strains of the causative agent, Mycobacterium bovis. The comparative intradermal tuberculin test (CIDT), questionnaire survey, post-mortem examination, bacteriology, and molecular typing were used to get a better understanding of the BTB prevalence among dairy farms in the study area. Based on the CIDT, our findings showed that around 30% of 2956 tested dairy cattle from 88 herds were positive for BTB while the herd prevalence was over 50%. Post-mortem examination revealed gross tuberculous lesions in 34/36 CIDT positive cattle and acid-fast bacilli were recovered from 31 animals. Molecular typing identified all isolates as M. bovis and further characterization by spoligotyping and MIRU-VNTR typing indicated low strain diversity within the study area. Conclusions/Significance: This study showed an overall BTB herd prevalence of 50% in intensive dairy farms in Addis Ababa and surroundings, signalling an urgent need for intervention to control the disease and prevent zoonotic transmission of M. bovis to human populations consuming dairy products coming from these farms. It is suggested that government and policy makers should work together with stakeholders to design methods for the control of BTB in intensive farms in Ethiopia.