Abstract

Background: TB in swine is natural and virtually common in developed countries where swine is farmed. Although this re-emerging disease is very common in developing country as well; there is scanty information on the prevalence of swine tuberculosis in Ethiopia. Therefore, this study was developed to assess the prevalence of swine tuberculosis by using bacteriological and histhopathological techniques.
Methods/Principal Findings: A cross sectional study was conducted at Bishoftu and Addis Ababa Abattoirs from September 2017 to May 2018 to estimate abattoir based prevalence of tuberculosis in swine, to isolate Mycobacterium species involved and to characterize the lesions. Five hundred and fifty six (556) swine were examined. Tubercle like granulomatous lesion were detected in 19.6% (109/556) of different organs of which 12% (69/556) was in lymph nodes, 5.7% (32/556) in the lungs, 1% (6/556) in the liver and 0.36% (2/556) in the spleen. Based on microscopic alteration 4.7% (26/556) of lesions were tuberculous granulomatous type with central necrosis, calcified foci, epitheloid cells admixed with lymphocyte and connective tissue boundries, 3.6% (20/556) pyogranulomatous and 2.5% (14/556) non necrotic granulomatous lesion without epitheloid cells and connective tissue capsules. The tuberculous lesions found in lymph node were statistically significant (P < 0.05) than in other organs. The multivariable logistic regression analysis showed that old aged swine were more likely to have characteristic tuberculous lesion (OR = 3.14, 95% CI, 1.62-6.09) than younger ones. From the tissue cultured, 7.5% (3/40) yield growth on primary culture media. The observed colony morphology was smooth whitish or yellowish color, sticky, off-white and breaks apart easily and two (5% (2/40)) of these growth were acid fast positive by Zeihl-Neelsen staining technique.
Conclusion/Significance: This study highlights that TB is prevalent in swine and pork can be source of tuberculosis to human when consumed under cooked. Therefore, routine abattoir inspections should be conducted, further molecular and biochemical research to isolate the species of microbacteria is highly recommended to elucidate the type of lesion and its magnitude in different body organs by considering large number of swine.

Keywords

mycobacterium tuberculosis, bacilli, Bishoftu, TB