World Health Organization(WHO) warned tourists in South Africa especially soccer fans heading to the World Cup to guard against mosquito bites and avoid contact with raw meat due to an outbreak of Rift Valley fever.

Officials in South Africa, the host of the 2010 World Cup from June 11 to July 11, have reported 172 human cases of the animal viral disease this year, including 15 deaths, it said.

Many tourists visit South Africa's game parks and WHO warned visitors to avoid contact with dead animals .

Aphaluck Bhatiasevi, WHO spokeswoman said that people should be aware there is Rift Valley Fever in several provinces and should take precautions when visiting those areas as they could be exposed to animals that could be infected.

A female German tourist who visited game reserves was confirmed as having the disease upon return from South Africa last month, the WHO said in a statement. Three other travelers fell ill with similar symptoms but all four have recovered.

The virus usually causes relatively mild flu-like symptoms and neck stiffness in people, progressing sometimes to hallucinations, dizziness or even coma, according to the WHO.

A small percentage of victims develop a hemorrhagic form which causes them to vomit blood, pass blood in feces, or bleed from the nose, gums, or skin. Half of such patients die.

Human cases have been confirmed in Free State Province, Eastern Cape Province, Northern Cape Province, Western Cape and North West Province, most after contact with infected livestock.

The WHO, a United Nations agency, said it was not advising any international travel restrictions to or from South Africa.

However, WHO recommends that visitors to South Africa to avoid coming into contact with animal tissues or blood, avoid drinking unpasteurized or uncooked milk or eating raw meat.

Who further caution travelers to take appropriate precautions against mosquito bites, either using insect repellents or mosquito nets.

A vaccine for humans has been developed but is not licensed and is not commercially available, according to the WHO.