August 01, 2010

 

 Rinderpest nearly eradicated worldwide

posted July 18, 2010
 

A disease that killed millions of cattle and contributed to the development of modern veterinary medicine could soon be the first animal disease eradicated by human efforts, according to the World Organisation for Animal Health (OIE).

The OIE announced June 17 that 176 countries and territories were currently recognized as free of rinderpest, but that 16 countries and some additional territories needed to be recognized as free of the disease prior to a declaration that the "cattle plague" had been eradicated. The viral disease affects domestic and wild hoofed animals, particularly cattle, buffaloes, yaks, swine, giraffes, and lesser kudus.

Rinderpest is one of the oldest recorded plagues of livestock, originating in Asia and first described in the fourth century, according to the book "Veterinary Virology." Devastating epizootics swept across Europe in the 1700s and 1800s, and a 1920 outbreak led to the founding in Paris of the Office International des Epizooties, which later became the OIE.

"Rinderpest was a devastating disease of cattle in Europe before it was finally eliminated in 1949," the book states. "It has been a scourge in sub-Saharan Africa ever since livestock farming was introduced in the late 1800s; remarkably, it was nearly eliminated from Africa in the 1980s by massive cattle vaccination programs, but regional wars and violence interceded, programs were stopped, and the disease made a rapid comeback in many areas."

The Food and Agriculture Organization of the United Nations has, since its foundation, helped member countries control rinderpest. In 1994, the organization worked with the OIE in launching the FAO's Global Rinderpest Eradication Program, which has helped control animal movement, eliminate infection reservoirs, and conduct surveillance, FAO information states.

Rinderpest could become the second disease, following smallpox in humans, to be eliminated through human efforts, and the eradication would follow centuries of efforts to control or wipe out the disease. Harm from rinderpest in the mid-1700s has been credited with helping to show French authorities the need for individuals trained to respond to animal disease outbreaks and contributed to the French comptroller general's support for a proposal to found the world's first veterinary school in Lyon, France, according to the book "Virus Diseases of Food Animals."

The morbidity rate following infection with the virus typically approaches 100 percent, and the mortality rate is typically between 90 percent and 100 percent, although cattle breeds indigenous to Africa have mortality rates of about 50 percent, the book states. The causative agent is also thought to be the archetype morbillivirus that gave rise to the canine distemper and human measles viruses 5,000 to 10,000 years ago.

The OIE announcement was published about four months after the death of Dr. Walter Plowright, a British veterinarian who developed a vaccine credited with greatly helping to eliminate the livestock disease. In 1999, he was awarded the World Food Prize for development of the inexpensive tissue culture vaccine, which induces lifelong immunity and which World Food Prize Foundation officials credit as "a key element in the quest to eliminate rinderpest."

Initial field use from 1956-1963 showed the vaccine was genetically stable and produced no adverse clinical effects, and Dr. Plowright later helped develop large-scale production techniques and identify the best conditions for widespread vaccination, according to the World Food Prize Foundation.

Following eradication, rinderpest virus will be stored in a "restricted number" of national and international laboratories. The OIE indicated the organization was preparing recommendations and guidelines to restricting use of the virus to research purposes.