Experimental Contagious Caprine Pleuropneumonia: A Long Term Study on the Course of Infection and Pathology in a Flock of Goats Infected with Mycoplasma capricolum subsp. capripneumoniae

R Lindberg,F Thiaucourt,HO Wesonga,G Bölske,C Wanjohi

doi:10.1186/1751-0147-45-167

Abstract

Contagious caprine pleuropneumonia (CCPP) is a major threat to goat farming in parts of Africa and Asia. It classically causes acute high morbidity and mortality early in infection, but little is known of its long term epizootiology and course. In this study, 10 goats were inoculated with Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae) and then mixed with 15 goats for contact transmission. The disease course was monitored in each goat for 56–105 days, whereafter the goats were killed and necropsied. Varying features signifying infection occurred in altogether 17 goats (7 inoculated, 10 in-contact). Clinical signs were severe in 8 goats but no fatalities occurred. Only 6 goats had serum antibody titres against M. capripneumoniae in ELISA. Fourteen goats (5 inoculated, 9 in-contact) had chronic pleuropulmonary lesions compatible with CCPP at necropsy and 7 of those showed M. capripneumoniae antigen in the lung by immunohistochemistry. Neither cultivation nor PCR tests were positive for the agent in any goat. The results indicate that the clinical course of CCPP in a flock may be comparatively mild, M. capripneumoniae-associated lung lesions may be present at a late stage of infection, and chronic infection may occur without a significant serological response.

Highlights

Contagious caprine pleuropneumonia (CCPP) is one of the most severe infectious diseases of goats, causing major economic losses in goat farming in Africa and Asia (Jones 1989)
It is argued that M. mycoides (SC) strains isolated at the end of contagious bovine pleuropneumonia (CBPP) outbreaks are less virulent than those from early cases (Provost et al 1987) and this possibly applies to CCPP as well
Up to 28 days post inoculation (p.i.). This surprising lack of early clinical signs was the reason for the later inoculation of 3 goats with another strain, which produced in one goat an episode of fever starting within the commonly observed 3-9 days p.i. (MacOwan & Minnette 1977)

Summary

Introduction

Contagious caprine pleuropneumonia (CCPP) is one of the most severe infectious diseases of goats, causing major economic losses in goat farming in Africa and Asia (Jones 1989). It is caused by Mycoplasma capricolum subsp. Long term survivors of acute disease may display chronic pleuropneumonia or chronic pleuritis (Kaliner & MacOwan 1976, Rurangirwa et al 1991) but cultural recovery of the agent has not been demonstrated in such late stage pulmonary lesions (MacOwan & Minnette 1978, Wesonga et al 1998). The present study was designed to elucidate these matters in experimental M. capripneumoniae infection of a large flock of goats

Methods

Results

Conclusion