Determination of the Prevalence of Contagious Bovine Pleuropneumonia in Kenya: Comparison of Complement Fixation Test and Bacterial Culture

Abstract

This study was carried out in Njiru and Dagorreti slaughterhouses with the objective of comparing the results of complement fixation test (CFT) and pathological lesions in lung samples taken for culture and sero-prevalence of Contagious Bovine Pleuropneumonia (CBPP) among cattle brought for slaughter.

A total of 804 serum samples and 40 suspected lung tissues were collected from both abattoirs for laboratory diagnosis. The serum and lung tissues were collected from adult cattle that were brought for slaughter. 416 serum samples were taken from Njiru and the other 388 from Dagoretti slaughterhouse.The serum samples were subjected to the complement fixation test and the lung tissues cultured in both solid media and broth. Growth of the microorganisms in the media was checked once a week for a period of one month. Any media that had no growth after a period of one month was recorded as negative.

Animals for slaughter originated from 22 districts and the majority were from the arid and semi-arid areas of Kenya. The number of sero-positive animals by CFT was 324 (40.3%). The mean sero-prevalence for the 22 districts was 40.3% ± 1.7.

The highest sero-prevalence was observed in Garissa (25.62%) and Moyale districts (24.38%).

The one way analysis of variance (Kruskal-Wallis test) indicated that there was no significant difference between districts on the sero-prevalence of CBPP (P=0.38). The mean sero-prevalence for males and females was 39.7% ± 1.9 and 42.4% ± 3.8, respectively, and this difference was not statistically significant (P= 3.841) with odds ratio (OR) = 0.9.

There was growth in four media where the lung samples were cultured for mycoplasma organisms. In broth, growth was visible within three to ten days as a homogenous cloudiness with whirls when shaken in four of the samples. On solid media, small colonies developed, 1 mm in diameter, with classical 'fried-egg' appearance in the same four samples. Seventeen (17) serum samples tested positive for CFT but corresponding lung samples on culture were all negative. One animal tested positive in both CFT and culture. Three animals tested positive after culture but were negative on CFT.

Based on these results, CBPP seems to be a major concern in many parts of Kenya and hence implementation of immediate control measures such as vaccination have been proposed. In addition, further studies in all other slaughterhouses in Kenya is suggested. There is need for improvement of the national veterinary infrastructure and education of livestock owners is also suggested.