31 March 2010Dozens of farmers, veterinarians and farm workers have been infected with Rift Valley fever in South Africa, and at least two people have died, the United Nations World Health Organization (WHO) reported today. Dozens of farmers, veterinarians and farm workers have been infected with Rift Valley fever in South Africa, and at least two people have died, the United Nations World Health Organization (WHO) reported today. Transmitted by mosquitoes, RVF is a dangerous disease that affects both livestock – including sheep, goats, cattle and camels – and humans, but is usually well-established in animal populations by the time the first human cases are observed. Most of the 63 people coming down with the virus came into direct contact with infected livestock or were somehow linked to farms housing animals confirmed to have RVF. All cases of RVF in the current outbreak have been confirmed by the National Institute of Communicable Diseases (NICD) in Johannesburg. According to WHO, there has been an ongoing outbreak of RVF affecting sheep, goats, cattle and wildlife on farms in seven of South Africa’s nine provinces. As of 29 March, nearly 80 farms have reported laboratory-confirmed cases in animals, with extensive deaths. South African authorities continue to investigate the outbreak and are also taking steps to enhance disease surveillance among cattle and in managing the infections. The last major outbreak in animals in the country took place between 1974 and 1976, with up to 20,000 animals affected. Humans become infected through mosquito bites or direct contact with infected material and liquids such as animal blood during slaughtering, while the uncooked milk of infected animals can also pose a risk. No cases of human-to-human transmission have ever been reported. While some infected people experience no detectable symptoms, others develop flu-like fever, muscle pain, headaches, joint pain, vomiting, loss of appetite and sensitivity to light. In more severe cases patients can also experience lesions in their eyes, neurological problems, liver impairment and haemorrhagic fever symptoms including widespread bleeding.