Contagious bovine pleuropneumonia (CBPP)

• Cause: contagious bovine pleuropneumonia (CBPP) is caused by a bacterium called Mycoplasma mycoides subsp. mycoides Small Colony (MmmSCSC).
• Signs:
  • CBPP is characterized by nonspecific signs of fever, loss of appetite, depression and a drop in milk production, followed by respiratory signs, which may include coughing, purulent or mucoid nasal discharges, and rapid respiration.
  • Pregnant animals may abort the fetus or give birth to stillborn calves Abortion and stillbirths: overview.
  • Severely affected cattle often die, typically within three weeks.
  • In calves up to six months of age respiratory signs of CBPP are less common and the primary sign is polyarthritis, especially of the carpal and tarsal joints, and resultant edema. Pain in the affected joint results in the animal being reluctant to move.
• Diagnosis:
  • Isolation and identification of MmmSC from clinical samples.
  • Polymerase Chain Reaction (PCR) based assays are commonly used for confirmation of the identity of the bacteria.
  • Less commonly older biochemical and serologic methods are used (growth inhibition, immunofluorescence, dot immunobinding on a membrane filter [MF-dot] test, agar gel immunodiffusion).
  • Post-mortem investigation Post-mortem on-farm will reveal abnormalities within the chest cavity, including; gross pathologic lesions of the lung (often affecting only one lung), the accumulation of a large volume of yellow fluid (often containing large fibrinous clots) and enlarged lymph nodes.
• Treatment:
  • Antibiotics of the tetracycline Oxytetracycline, macrolide Erythromycin and fluoroquinolone families can be effective in treatment; however in some cases the bacteria is not completely eliminated and subclinically infected carriers can develop.
• Prognosis:
  • The mortality rate of CBPP rate ranges from 10% to 80%, although mortality greater than 50% is rare unless in naïve herds.
  • Animals that recover are frequently weak and emaciated, and may remain chronically infected.
  • Euthanasia Euthanasia: techniques, on welfare grounds, should be considered for some cases.
  • CBPP is a notifiable disease Notifiable diseases in the UK.

Geographic incidence

• CBPP is widespread throughout the whole of sub-Saharan Africa; with outbreaks reported in Ethiopia, Angola, Namibia, Tanzania, Zambia, DRC and Kenya.
• Outbreaks have also been reported in Asia (India, Bangladesh and Myanmar) and the Middle East, probably derived from importation of infected cattle from Africa.
• The USA has been free from CBPP since 1892.
• The UK has been free of CBPP since 1898.
• The disease was introduced to South Africa in 1853 and eliminated by 1924.
• Australia has been free from CBPP since the 1970s. 
• China has been free from CBPP since the 1980s. 
• CBPP was eliminated from Europe in the nineteenth century, but there were outbreaks in Portugal (1951), Spain (1957), France (1984), Italy (1990) and Portugal (1999). 

Age predisposition

• The more severe respiratory forms of CBPP are observed in adult animals, whilst the polyarthritic forms are more commonly observed in calves under 6 months of age.

Breed/Species predisposition

• Cattle (Bos Taurus Bos Taurus), Zebu (Bos indicus) and Asian buffalo (Bubalus bubalis) are the primary hosts for MmmSC under natural conditions. To a lesser degree yak (Bos grunniens) are also a host species and one single case has been reported in American buffaloes (Bison bison).

Public health considerations

• There is no evidence that humans are infected by MmmSC.

Cost considerations

• CBPP is one of the most important infectious diseases of cattle in Africa. Naïve herds can experience losses of up to 80%.
• Animals that recover can be weak and emaciated and may remain chronically infected. This can result in underdeveloped adults and also recurrent infections within the herd.
• In the UK, affected herds may be liable to compulsory slaughter under the Animal Health Act 1981.