According to an article in the New Scientist, the depopulated and apparently primevally wild Africa seen in wildlife documentary films was formed in the 19th century by disease, a combination of rinderpest and the tsetse fly. In 1887, the rinderpest virus was accidentally imported in livestock brought by an Italian expeditionary force to Eritrea. It spread rapidly, reaching Ethiopia by 1888, the Atlantic coast by 1892 and South Africa by 1897. Rinderpest, a cattle plague from central Asia, killed over 90% of the cattle of the pastoral peoples such as the Masai of east Africa. With no native immunity, most of the population – some 5.5 million cattle – died in southern Africa. Pastoralists were left with no animals - their source of income - and farmers were deprived of their working animals for ploughing and irrigation. The pandemic coincided with a period of drought, causing widespread famine. The starving human populations died of smallpox, cholera, typhoid and other diseases imported from Europe. It is estimated that two-thirds of the Masai died in 1891.