Disease transmitted by tick bite

The mere mention of Congo fever sends shivers down one's spine - and with good reason: the disease claims the lives of 10% to 40% of infected people.

Crimean-Congo haemorrhagic fever causes its carrier to bleed out through every orifice. People become sick within one to nine days after exposure to the virus. The symptoms include severe fevers, muscle ache, vomiting and abdominal pain.

Patients often develop a rash and may bruise easily, vomit blood or have gum and nose bleeds, or pass blood through their stool and urine.

There can be internal bleeding, including in the brain or the lungs. Patients can slip into a coma from organ failure and death occurs within five to 14 days.

Congo fever has been widely reported in Africa and in South Africa. It is transmitted by the Hyalomma tick, known in South Africa as the "bontpoot" tick, which thrives in the arid north-western parts such as the Karoo and the western Free State.

People can be infected through a bite from an infected tick, or if fluid from a tickenters into a cut or graze on the skin or splashes into the eye, nose or mouth.

Infections can also occur by coming into contact with infected animals. This places farmers, herders, abattoir workers, veterinarians and hunters at high risk.

Cases of Congo fever have been reported in South Africa since 1981, when it was first identified. According to the National Institute for Communicable Diseases, about 20 cases are diagnosed in South Africa each year.

The World Health Organisation rates the fatality rate at 10% to 40%.

Patients who recover usually show sudden improvement on the 10th day, but they should refrain from intimate contact with others for six weeks.