Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides (Mmm), is a highly contagious bacterial infectious disease of the respiratory tract in cattle.

Bovine pulmonary disease is now predominantly found in sub-Saharan Africa

Domestic and zebu cattle as well as yak and water buffalo are susceptible. There are isolated reports of occurrence in sheep, goats, and American bison. However, these do not play an epidemiological role

Bovine pulmonary disease is transmitted primarily by direct animal-to-animal contact. The transmission is aerogenic (droplet infection)

3 weeks to 6 months

Clinical symptoms include respiratory symptoms (dyspnea, cough, nasal discharge), anorexia, and fever

No therapy is recommended

Live vaccines are used in endemic areas. Vaccination is not recommended for countries with low prevalence or for CBPP-free areas.

Bovine pulmonary disease does not currently occur in Austria or Europe. The last outbreak in Europe took place in Portugal in 1999.

Mmm belongs to the mycoplasmas, a group of cell-wallowing bacteria of the class "Mollicutes". It is part of the Mycoplasma mycoides cluster, which consists of five different mycoplasma strains that cause disease in cattle and goats and are closely related phenotypically and genotypically(Mycoplasma mycoides subsp. mycoides, Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum, Mycoplasma capricolum subsp. capripneumoniae, Mycoplasma leachii).

CBPP has been known since the 18th century and spread worldwide in the second half of the 19th century due to livestock trade. It was eradicated in many countries in the early 20th century through mercy strategies (UK, USA) or the combination of vaccination campaigns and mercy (Australia). Today, the disease is endemic in sub-Saharan Africa, causing great economic damage. Little is known about the current situation in Asia. In Europe, the last case occurred in Portugal in 1999.

Symptomatology

Bovine pneumonic disease can be acute, subacute, or chronic.

The acute form is dominated by high fever (up to 42°C) and marked respiratory symptoms (cough, chest pain, polypnea, dyspnea, nasal discharge). In endemic areas, subacute and chronic forms predominate. These animals show little or nonspecific symptomatology such as cough and progressive emaciation to cachexia. In calves, CBPP is manifested by arthritis (joint swelling) rather than respiratory signs.

The clinical expression of the disease is strongly influenced by the virulence of the particular strain and the susceptibility of the host (breed, age, immune status). When a flock is newly infected, mortality can be very high (up to 90%), whereas it is low (<10%) in endemic areas.

Pathologic changes in the thoracic cavity are considered characteristic. CBPP is characterized by fibrinous bronchopneumonia and pleuritits. In the acute phase, pleural effusions of several liters may form, whereas in the chronic phase, fibrotic adhesions form between the lungs and the chest wall. Changes in the lungs are usually unilateral, preferentially affecting the caudal lobe of the lung. In the early phase of the disease, a typically marbled lung surface is seen, resulting from the encounter of healthy and diseased tissue, separated by thickened interlobular septa. Furthermore, encapsulated necrotic areas, so-called sequestra, are typical. In calves, fibrinous polyarthritides are predominantly observed.

Transmission

CBPP is a highly contagious infectious disease that can spread rapidly. It is mainly transmitted aerogenically. The pathogens have also been detected in saliva, urine, fetal membranes, uterine discharge, and semen. Transplacental transmission is possible. The main source of infection is silent carriers of chronic infection, although live pathogens can persist in encapsulated lung lesions (sequestra) for up to two years and can be reactivated by immunosuppression.

The spread of CBPP occurs primarily through livestock traffic. Countries where CBPP is present are therefore excluded from international livestock trade.

Clinical diagnostics are unreliable, since chronic carriers in particular often show little or no clinical symptoms. A suspected case must always be clarified by microbiological, molecular biological, pathological or serological methods. Since the pathomorphological changes are very characteristic, the slaughterhouse examination is suitable as a monitoring method.

Sampling of the living animal:

• Nasal swab
• Bronchoalveolar lavage (BAL)
• Pleural effusion (by puncture)
• Serum

Sampling on dead animal:

• Lung lesions
• Lung or mediastinal lymph nodes
• Pleural fluid
• Synovial fluid

Detection method:

• Direct pathogen detection by culture on selective culture media.
• Molecular detection: PCR
• Serological detection: Complement Binding Reaction (CFT), Antibody ELISA, (Immunoblot)