A history of the prevalence and control of contagious bovine pleuropneumonia in China.

Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides small colony type, was once the most damaging infectious animal disease in China, second only to rinderpest. Between 1949 and 1989, 178,570 cattle died of CBPP, causing estimated losses of 356 million RMB (1RMB=approx. £0.094, US$0.15, €0.11 at 27th January 2011). In 1956, in an effort to control the disease, a virulent strain of the causative organism (Ben-1) was attenuated by multiple passages in rabbits. The resultant vaccine achieved a high protection rate in cattle with a duration of immunity of 28 months. Vaccines were also prepared in sheep to increase the antigen yield and then in Tibetan sheep because it caused fewer adverse reactions in yaks and related species. The last CBPP infected animal was identified in 1989 since when no more cases have occurred. In 1992, vaccination of cattle was stopped. In 2008 China submitted an application to the World Organization for Animal Health (OIE) to be declared CBPP-free. Crown