As early as 1913, a disease fitting the description of RVF was blamed for the loss of sheep in the Rift Valley of Kenya. In July 1930, Kenya was hit with very heavy rains that substantially increased the wetlands where mosquitoes bred, at the same time, occurrence of the disease increased and one of the carriers for the disease was found to be the mosquito. Those studying the disease made the connection between increased rains, wetlands, mosquitoes, disease and were able to identify the associated virus. Since that time, major outbreaks have been noted throughout sub-Saharan Africa, with occasional outbreaks in other parts of the continent.