Bovine Tuberculosis in East Africa

Abstract

The zoonotic Mycobacterium bovis is a pathogen of significance in the dairy industry in many parts of the world. Although the pathogen primarily affects cattle, it has a wide host range including humans. A cross-sectional study was carried out in three agro-ecological zones of Tanzania, namely the southern highlands zone (SHZ), eastern zone (EZ) and northern zone (NZ), to examine the status of the disease in cattle, in order to inform control measures. A total of 391, 169 and 401 cattle were tested for bovine tuberculosis (bTB) in the SHZ, EZ and NZ respectively using the Single Intradermal Comparative Cervical Tuberculin Test (SICTT). Results showed that the prevalence of bTB was higher (P<0.05) in EZ 2.37% (n = 169) compared to SHZ 1.3% (n=391) and NZ, where no positive result was recorded (n = 401). Thirty three cattle from SHZ and seven from EZ showed inconclusive results. In Kenya, 625 cattle from four sites within agro-pastoral and pastoral production systems were tested. In one area of Mwingi County, eastern Kenya, all the 161 cattle tested negative; while in the other three sites of Migori, in Nyanza, West Pokot and Laikipia in the Rift Valley, prevalence of 4-6% was obtained with SICTT. Bovine TB occurs in the region and may pose a public health threat through occupational activities and/or consumption of animal products, especially since no obvious clinical signs were observed in positive animals. Policy issues on how to deal with positive cases, creation of awareness on this important zoonotic disease, and a simple test to quickly identify sick animals in the field require urgent attention.

Key Words: Agro-ecological zones, Mycobacterium bovis, Zoonoses