Abstract  

Rift Valley Fever (RVF) is an acute, fever-causing viral disease most commonly found in domesticated animals (cattle, sheep, goats, camels), but known to sometimes infect and cause illness in humans. The disease is caused by a virus of the genus Phlebovirus, in the family Bunyaviridae.  Veterinary officers first reported and described the disease during the 1910s in Kenya’s Rift Valley, and in the 1920s veterinarians working in Kenya researched the infection and published the first scientific description and analysis of RVF in the early 1930s.  The disease is found anywhere in eastern and southern Africa where sheep and cattle are raised, but the virus exists in most of sub-Saharan Africa, including Madagascar. In September 2000, a RVF outbreak was reported outside of Africa for the first time, in the Arabian Peninsula.  Outbreaks of RVF can lead to significant economic losses and trade reductions, and in Saudi Arabia there was also loss of human life due to infection.  The same had happened in Egypt in 1977, when there was estimated to be 600 human deaths.  An outbreak in West Africa in 1987, linked to the construction of the Senegal River Project, also caused infection in humans.  In 1997 a major outbreak in Kenya was reported to have caused infection in 90,000 people, leading to nearly 500 human deaths.  The epizootics in Arabia since 2000 have been unusual in their scale and duration, the largest reported previously occurring in Kenya (1950-51), when it is estimated that over 100,000 animals died.  This paper explains how RVF was first identified in Kenya, and then charts what is known of its occurrence in Kenya up to the 2020s.  Archival sources on RVF in Kenya are incomplete, but they allow us to establish a reasonably clear picture of the pattern of epizootics and we can readily the efficacy of inoculation when it was introduced.   This was highly effective until the 1980s, when the erosion of state veterinary funding across East Africa led to RVF inoculations being stopped.  By the turn of the century, Kenya veterinary officers had little practical knowledge of the disease, while studies among pastoralists in the 2010s suggest that indigenous knowledge of RVF had also by then virtually disappeared among some herding communities.  In the 2020s, outbreaks of RVF continue to occur, although our awareness of RVF is hampered by problems of differential diagnosis (as has always been the case).  Inoculations can be made available to herders, but with reduced awareness of the disease herders seem unwilling to accept the costs.  In these circumstances, the recurrence of epizootics seems inevitable, and it is argued that cross-infection to humans is likely to become increasingly common. 

Bio 

David M. Anderson is Professor in African History, at the Global History & Culture Centre, University of Warwick, a Fellow of the British Academy, and a Research Associate in History at Stellenbosch University.  Initially trained in environmental history, he first researched the experience of pastoralists in East Africa under colonialism.  He has subsequently published extensively on the wider colonial and Cold War histories of eastern Africa, including studies of environmental change, violence, insurgency, and counter-insurgency.  He is currently researching the history of Namibia’s Caprivi Strip, c.1890 – 1999. 

Click here to register