Contagious caprine pleuropneumonia

Peracute cases die within 24-72 hours with little warning. Acute cases show high fever (41-44 degrees C), anorexia, depression, nasal discharge that turns from straw-coloured to purulent, a painful productive cough, laboured abdominal breathing and chest pain; animals finally become recumbent. At necropsy one lung is usually consolidated, the pleural cavity holds a large volume of fluid, and fibrinous pleurisy with adhesions is frequent.

Contagious caprine pleuropneumonia is caused by Mycoplasma capricolum subsp. capripneumoniae (Mccp), a wall-less bacterium of the mycoides cluster that grows very slowly and is hard to isolate. Inhaled organisms attach to the respiratory epithelium and halt ciliary activity. Surface antigens such as galactan polysaccharide and lipoproteins activate inflammatory and oxidative cascades, producing vasculitis and a fibrin-rich cellular exudate. The outcome in acute disease is a severe serofibrinous pleuropneumonia, characteristically in one lung, with heavy pleural effusion. Microscopically the pneumonia is interstitial with intralobular oedema. Goats and sheep that recover may remain latent carriers without clearing the organism.

Goats of all ages and both sexes are the main hosts; sheep in mixed flocks are occasionally infected and may act as a reservoir, and cattle are not affected. Wild ruminants are susceptible: outbreaks struck wild goats, Nubian ibex, Laristan mouflon and gerenuk in a Qatar reserve, gazelles in the United Arab Emirates, and sand gazelles, where mortality reached 70%. The disease was first described in Algeria, and Mccp has been isolated in Oman, the United Arab Emirates, Saudi Arabia, Tunisia, Sudan, Turkey and several other African and Asian countries. Its real range is probably wider because it is confused with other pneumonias. Spread is mainly by inhaling aerosols from infected goats. It is WOAH-listed and not zoonotic.

Peste des petits ruminants and pasteurellosis are the main field confusions; pasteurellosis can be separated by the distribution of gross lung lesions. Other mycoplasmas of the mycoides cluster give similar lung lesions, but Mycoplasma mycoides subsp. capri usually adds arthritis, mastitis or keratitis and grows quickly in culture. Contagious caprine pleuropneumonia is suspected when lesions are confined to the respiratory tract and one lung with profuse pleural fluid; PCR is the preferred confirmation.

Lungs, pleura and pleural cavity, bronchi and bronchioles, respiratory epithelium, thoracic lymph nodes

Inactivated, saponin-adjuvanted whole-cell vaccines; historically slaughter of infected goats plus vaccination of in-contact goats; limiting contact with infected flocks, as spread is by aerosol.

Morbidity up to 100% and mortality usually around 80% in naive herds (case fatality 60-100%), lower in endemic areas where antibiotics are widely used. Treated survivors may stay latent carriers.

Capra aegagrus