Epidemiological investigations of contagious caprine pleuropneumonia in selected districts of Borana zone, Southern Oromia, Ethiopia

Abstract

From November 2016 to April 2017, a cross-sectional study to determine the sero-prevalence of contagious caprine pleuropneumonia (CCPP) and to investigate its epidemiology was conducted in selected districts of Borana zone in Ethiopia. In addition, the study aimed at identifying Mccp antigens using species specific primer of PCR. A multistage random sampling was implemented to select districts, pastoral associations (villages), and households. A total of 890 serum samples of small ruminants that had not been vaccinated (goats n = 789 and sheep n = 101) were collected and screened for the presence of antibodies against Mycoplasma capricolum subspecies capripneumoniae using a competitive enzyme-linked immunosorbent assay. Lung tissues and pleural fluid samples were collected from 3 sero-positive and clinically suspected goats for isolation of Mycoplasma capricolum subspecies capripneumoniae. Serology showed that overall 31.2% (246/789) of goats and 12.9% (13/101) of sheep were positive with statistically significant differences between districts (p = 0.001). Multivariable logistic regression analysis revealed that goats from Moyale and Yabello districts had higher odds of being positive than goats from Elwoya district with odd ratios of 2.05 and 1.61, respectively. Age of goats was also significantly associated with sero-positivity (OR = 1.47; CI 95% 1.2-1.8). Mycoplasma capricolum subspecies capripneumoniae was identified in 6 (75%) of the tissue samples using species-specific primer of PCR. Besides improving the understanding of the epidemiology of CCPP in the selected districts and demonstrating its wide distribution, the study highly also provides evidence of the possible role of sheep in the maintenance of the disease.

Keywords: CCPP; Risk factors; Sero-prevalence; cELISA.

Fig. 1

Map of Ethiopia showing study areas

Fig. 2

Clinical symptoms of CCPP as reported by respondents (N = 161)

Fig. 3

Proportion of sero-positivity in goats by locality

Fig. 4

Postmortem finding of CCPP infected goats. a Accumulation of lung exudate in thorax cavity; b fibrous adhesion of lungs to the chest wall; c froth in the trachea; d enlarged respiratory (mediastinal) lymph nodes; e lung with areas of pneumonia; and f lung exudate containing large clots of fibrin

Fig. 5

Agarose gel electrophoresis of PCR products (316 bp) amplified with Mccp-specific primers. Lane M: 100 bp DNA molecular weight marker; lane P: positive control; lane N: negative control; lane E: extraction control; lanes 1–8: samples