15 dead in World Cup fever outbreak
The World Health Organisation (WHO) has warned people travelling to South Africa about the risk of contracting Rift Valley fever.
The warning comes as hundreds of thousands of tourists prepare to visit the country for the World Cup.
The Rift Valley fever outbreak has infected more than 170 people and led to deaths of at least 15 people.
WHO is not advising travel restrictions for South Africa, but it is warning tourists to take precautions.
Visitors are being advised to avoid contact with raw animal products and to cover up against mosquitoes which may carry the viral disease.
Most human infections result from contact with the blood or raw flesh of infected animals.
Tourists planning to attend next month's World Cup are being encouraged to be wary of the disease if they visit farms or game reserves.
The warnings are another set-back for the South African tourism industry, which has faced a tough task overcoming the country's reputation for violent crime.
TRANSMISSION TO HUMANS
- The vast majority of human infections result from direct or indirect contact with the blood or organs of infected animals. The virus can be transmitted to humans through the handling of animal tissue during slaughtering or butchering, assisting with animal births, conducting veterinary procedures, or from the disposal of carcasses or fetuses. Certain occupational groups such as herders, farmers, slaughterhouse workers and veterinarians are therefore at higher risk of infection. The virus infects humans through inoculation, for example via a wound from an infected knife or through contact with broken skin, or through inhalation of aerosols produced during the slaughter of infected animals. The aerosol mode of transmission has also led to infection in laboratory workers.
- There is some evidence that humans may also become infected with RVF by ingesting the unpasteurized or uncooked milk of infected animals.
- Human infections have also resulted from the bites of infected mosquitoes, most commonly the Aedes mosquito.
- Transmission of RVF virus by hematophagous (blood-feeding) flies is also possible.
- To date, no human-to-human transmission of RVF has been documented, and no transmission of RVF to health care workers has been reported when standard infection control precautions have been put in place.
- There has been no evidence of outbreaks of RVF in urban areas.