Public Health News South Africa

Avoiding tick bite fever

Tick bite fever is still considered a risk in the Free State, Northern Cape, Eastern Cape and Kruger National Park and travellers should take precautions against contracting the disease. The more common occurrence is that of spotted fever rickettsiosis, otherwise known as tick bite fever, but there have been two cases of Crimean-Congo Haemorrhagic Fever (CCHF) reported recently in Bloemfontein.

Dr Pete Vincent of the Netcare Travel Clinics and Medicross Family Medical and Dental Centres says the risk of travellers getting CCHF is extremely low. Infections are generally only seen in people who come into regular contact with livestock in endemic areas, as well as in healthcare workers that serve those areas.

"While the occurrence of CCHF in South Africa is rare, unfortunately, the same can not be said of tick bite fever," he states.

"Over ten cases of tick bite fever have been reported to Geosentinel travel clinics by travellers who holidayed in South Africa in the past two months.

"In an unpublished paper that analysed over 40 000 travellers who returned ill from their travels around the world, 26% became ill following a trip to sub-Saharan Africa. Six percent of these had tick bite fever because of travelling in South Africa. The most commonly listed endemic areas were the Eastern Cape and Kruger National Park where diseased ticks are found in undergrowth, forest fringes and grasslands, and can brush on to your clothing or skin."

Avoiding tick bites

To avoid the tick bite scourge, he recommends that travellers take the following precautionary measures:

  1. Check whether the area and place you are visiting has a high prevalence of tick bite diseases.
  2. Wear long trousers that can be tucked into long socks or boots.
  3. Wear closed shoes.
  4. For added protection, spray fabric insecticides, such as Permethrin on to your clothing.
  5. Inspect your clothes and body for ticks immediately after potential exposure.
  6. Extract any spotted ticks as soon as possible, using tweezers. The tweezers should be placed as close as possible to the skin, over the tick's mouthparts. The tick should be pulled slowly, straight up and out, with care not to squeeze its stomach contents into the bite site.

CCHF Symptoms:

CCHF is caused by becoming infected with a RNA virus of the Nairovirus genus transmitted by Hyalomma ticks. Human infection occurs after a bite, crushing of an infected tick, or contact with infected animal blood. The fatality rate is 20 to 35%, says Dr Vincent. Although rare, human-to-human transmission can occur via contact with infected blood or other bodily fluids. The disease was first identified in the Crimea in 1944 and called Crimean haemorrhagic fever. In 1969, it was diagnosed in patients in the Congo, thus resulting in the current name.

The onset of CCHF is sudden. Patients may have a range of flu-like symptoms including headaches, high fever, muscle pain, lower back pain, cold shivers and hot sweats. As the illness progresses, severe bruising and nosebleeds could occur.

Tick bite fever symptoms:

With tick bite fever there is an eight-day incubation period. "The bite site will develop black scabs, which can result in open wounds and swelling of lymph glands, close to the bite site, could become visible. At day eight, one usually gets onset fever, muscle pain and a headache. Three days later patients can present a macular or skin rash that appears as small, flat red spots."

Should symptoms show, seek treatment immediately. "Supportive and antibiotic treatments with tetracycline are imperative for a cure. In South Africa tick bite fever is generally mild," concludes Dr Vincent.

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