Camel Brucellosis: Sero-prevalence and Pathological Lesions at Slaughterhouses in Garissa County, Kenya

Abstract

Camel brucellosis is an infectious disease, mostly presenting in chronic state; caused by Brucella organisms, which also affect other animals including man. There is little information in Kenya on the prevalence of the disease in camels to inform need for prevention and control measures. This study aimed at determining the presence of the disease in slaughtered camels in Garissa County through serological testing and pathological lesions encountered at meat inspection. Three sub-counties: Garissa Central (represented by Garissa Township), Garissa East (represented by Dadaab) and Garissa West (represented by Balambale) were purposefully and randomly selected based on presence of camel slaughterhouses and accessibility. One hundred and sixty camels were selected from 238 brought to the slaughterhouse during the visits based on the clinical manifestations suggestive of brucellosis observed on ante-mortem examination and clinical history obtained from the owners of the animals. The three main clinical signs that suggested brucellosis were lameness, swollen lymph nodes and history of abortion. Seroprevalence determination involved blood collection from the jugular vein and screening the serum for presence of Brucella antibodies using Rose Bengal Plate Test ,Serum Agglutination Test, Competitive- Enzyme Linked Immuno Sorbent Assay and Agar Gel Immuno-diffusion Test. The selected 160 test camels, were followed into the slaughterhouse, where respective condemned organs were further examined grossly and microscopically recording the observed changes. It is, however, noted that the observed changes are not pathognomonic for brucellosis; they can also be due to other disease(s). Out of the 160 camels tested, 15 (9.37%) were positive for Brucella antibodies; including 4/50 (8%) in Garissa Township; 5/50 (10%) in Dadaab and 6/60 (10%) in Balambale. Using chi-square statistics the sensitivity of the four serological tests were not significantly different (p=0.999). xv Seventy eight (48.7%) camels had one or more condemned organs at meat inspection. The common gross lesions encountered were fibrin depositions 3 (1.8%), enlargement of lung 2 (1.2%), pericarditis 38 (23.7%), and hepatomegaly with nodular liver lesions 79 (49.3%), enteritis 5 (3.1%), haemorrhages and congestion of visceral organs (lung and kidney) 6 (3.7%). Histopathological pictures included: cellular infiltration in lymph node 9 (5.6%), hypoplasia of lymphocytes 6 (3.7%), collapse of alveoli 5 (3.1%), oedema, congestion 4 (2.5%), fatty degeneration in liver 3 (1.8%) and haemorrhages in kidney1 (0.6%). In conclusion, this study showed that brucellosis is prevalent in camels in Garissa County. However, further research should be done in the whole country. Since the four tests were not significantly different, with respect to picking positive cases, RBPT is recommended as a screening test, since it is cheap, quick, and easy to carry-out. The other three can be used to establish respective antibody titres. Standard biosecurity measures at slaughterhouses and farms needed to be enhanced for the control and prevention of Brucella infection to animals and human.