Nearly 30 years after smallpox was eradicated from the face of the earth, it still stands alone as the only pathogen to have been deliberately eliminated (Though efforts on guinea worm and polio are getting close). Catching up on back issues of Science, I was surprised to learn that, at long last, there is now another virus very close to eradication. Rinderpest. The only catch: it doesn’t affect humans. But that doesn’t make the prospect of rinderpest eradication any less stunning.
Quick background: Rinderpest is a viral disease that afflicts livestock, mainly cattle. It is brutal, often killing a third of a herd. A century ago, it spread throughout Asia, Africa, and Europe, but various efforts, culminating in a sustained international campaign, begun in 1994, has driven it to isolated patches in Africa. Lately, it’s been confined to Kenya, and now may be even gone from there.
Just because it’s a bovine disease, though, doesn’t mean it doesn’t have human impact. Consider this passage from the Science story (subscription required), describing an outbreak in South African in 1897 that killed about 90% of the cattle population, as well as other livestock and local game:
With herding, farming, and hunting all but gone, mass starvation set in. An estimated one-third of the population of Ethiopia and two-thirds of the Maasai people of Tanzania died of starvation. The rinderpest epizootic also altered the continent’s ecological balance by reducing the number of grazing animals, which had kept grasslands from turning into the thickets that provide breeding grounds for the tsetse fly. Human sleeping sickness mortality surged.”
More recent outbreaks have likewise proven devasting to cattle and human populations alike; a particularly virulent outbreak in Sudan in the late 1980s killed 80% of calves, and with cow milk unavailable, human children began to starve, resulting in a horrible famine.
Another example of how we’re just a part of one big ecosystem.
Eradication is on target for 2010. Can’t wait to toast this one.