Two infectious diseases have successfully been eradicated&colon; smallpox and rinderpest. Spotted hyenas may contract brucellosis, rinderpest and anaplasmosis. To date, two diseases have been eradicated using herd immunity and vaccination&colon; rinderpest and smallpox. They were victims of the (now eradicated) viral illness rinderpest. By the end of the century rinderpest had been eradicated from most countries. Rinderpest outbreaks have also contributed in population loss. PPR is also known as goat plague, "kata", syndrome of stomatitis-pneumoenteritis, and ovine rinderpest. In 1968, large numbers of gaur were killed in an outbreak of rinderpest. This was followed by a far more serious outbreak of Rinderpest which occurred in 1891. It is considered feasible to eradicate ovine rinderpest in 15 years. The rinderpest eradication effort is estimated to have cost $5 billion. In the 1930s the tamaraw population declined due to rinderpest, a viral disease affecting cattle. Partial resistance to rinderpest led to another increase in the frequency of zebu in Africa. The term "Rinderpest" is a German word meaning "cattle-plague". Rinderpest continued to infect 90% of Africa's cattle.