Rift Valley Fever confirmed in “mystery” African-disease outbreak

Abstract

Amysterious disease, with features of haemorrhagic fever, is reported to have killed up to 350 people in Kenya in about a month, and an unknown number in neighbouring Somalia. Rift Valley Fever (RVF) virus has now been isolated, but experts suspect that the virus may not be the only cause. An international surveillance team has been visiting and collecting samples in the 20 Kenyan villages where most of the deaths occurred. The disease—characterised by high fever, headaches, vomiting, diarrhoea, and bleeding—was initially feared to be caused by Ebola virus, but this possibility has been excluded. Pointing out that the affected population is undernourished and has various infections associated with lack of clean drinking water, WHO notes that other diseases, such as shigella and malaria, could be involved. Another concern, given the large numbers of domestic and wild animals also affected, is anthrax. “We expect the possibility of a mixture of infections, and therefore will continue to test for anthrax”, said Kenya's director of medical services, James Mwanzia. So far, RVF virus has been isolated from three cases by the WHO collaborating centre at the National Institute of Virology in South Africa. First isolated in 1931, RVF virus usually causes a disease similar to dengue fever—a small proportion of cases develop haemorrhagic complications, with a high fatality rate. Recent flooding in the affected area has created ideal conditions for the mosquito vectors of RVF virus to breed. Agencies in Kenya, the US Centers for Disease Control and Prevention, and WHO are continuing tests.