African tick bite fever (ATBF) is a spotted fever caused by rickettsiae bacteria, specifically Rickettsia africae. The most commonly reported spotted fever among United States patients following international travel is African tick bite fever, caused by Rickettsia africae. Almost 90 percent of imported spotted fevers occur among travelers to sub-Saharan Africa.
Travelers to sub-Saharan Africa or the West Indies are at risk of developing the disease. Cases of African tick bite fever have been more frequently reported in the literature among international travelers. Outdoor activities including game hunting, safari, and backpacking may increase risk. Travel between November and April and travel to South Africa have been identified as other risk factors. Recent studies have indicated that between four and eleven percent of travelers to rural southern Africa had serolocal evidence of recent rickettsial infection. It is important to take personal protective measures against ticks when visiting these areas.
Mayo Clinic Minute: Tips to best remove ticks
How it Spreads
You can catch ATBF by being bitten by an infected tick. Two species of hard ticks, Amblyomma variegatum and Amblyomma hebraeum are the most common vectors of R. africae. Typically, A. hebraeum transmits the bacteria in South Africa while A. variegatum carries R. africae throughout West, Central and East Africa and through the French West Indies. Other species of Amblyomma in sub-Saharan Africa can also transmit R. africae and it may be that up to 100% of Amblyomma ticks in sub-Saharan Africa carry R.
Up until 1998, it was thought that only ticks in sub-Saharan Africa carried R. africae. However, a case of locally transmitted African tick bite fever in the French West Indies led to the discovery of R. africae carried by Amblyomma varigatum ticks introduced through cattle shipped from Senegal to Gaudeluope more than a century ago. R. africae has been isolated from ticks on several Caribbean islands, though the only cases in humans in the Caribbean have occurred in the French West Indies.
Read also: Experience Fad's Fine African Cuisine
After the rickettsia bacteria infects humans through a tick bite, it invades endothelial cells in the circulatory system (veins, arteries, capillaries). The body then releases chemicals that cause inflammation, resulting in the characteristic symptoms like headache and fever. Rickettsia bacteria species like R.
Signs and Symptoms
ATBF is typically a mild-to-moderate disease. Symptoms usually appear within two weeks after a tick bite and can include fever, headache, muscle soreness, and a rash. At the site of the tick bite will be a red skin sore with a dark center.
Symptoms of conditions caused by tick bites could include:
- Fever
- Chills
- Muscle pain
- Headaches
- Tiredness
- Itchiness or irritation
- Nausea and vomiting
- Swollen lymph nodes
- Allergic reaction to eating red meat
- Skin rash
The rash might look like a circle or a bullseye. Or it might be small, red or purplish spots that are actually spots of blood under your skin (petechiae).
What does a tick bite look like?
Tick bites themselves often don’t cause noticeable symptoms like mosquito bites do. Sometimes, they might cause a bump, swelling or itching. You most often know you were bitten by a tick because you catch them attached to you.
Read also: The Story Behind Cachapas
Where on your body do ticks bite?
Ticks can climb onto any part of your body. But they often move to warm, moist areas to latch on. Common places on your body to find ticks include:
- On your scalp and neck
- In your groin
- Behind your knees
- In your belly button
- In or around your ears
- In your armpits
- Around your waist
Why do ticks bite?
Ticks bite because blood is their source of food. Young ticks (nymphs) hatch in spring and find an animal or person to feed off of. They mature into adults and take another meal in the fall.
Diagnosis
Diagnosis of ATBF is mostly based on symptoms, as many laboratory tests are not specific for ATBF. Biopsies or cultures of a person's tick wound (eschar) are used to diagnose ATBF.
Commercial antibody tests for RMSF can be used to confirm any spotted fever infection. However, most commercial tests are unable to distinguish among the different species of spotted fever group Rickettsia. More specialized tests can be performed at CDC laboratories.
Treatment
Spotted fever infections can range from mild to life-threatening. Eschars may or may not be present. Doctors immediately prescribe an antibiotic, usually doxycycline, if they suspect a spotted fever based on symptoms and the potential for exposure to infected ticks-even if laboratory test results are not yet available. The antibiotic is given for 5 days.
Read also: Techniques of African Jewellery
Prevention
Preventing exposure to ticks is the best defense against diseases spread by ticks. Tick exposure can occur year-round, but ticks are most active during warmer months. Ticks live in grassy, brushy, or wooded areas, or even on animals, so spending time outside camping, hiking, gardening, or hunting will bring you in close contact with ticks. Many people get ticks in their own yard or neighborhood.
Prevention of ATBF centers around protecting oneself from tick bites by wearing long pants and shirt, and using insecticides like DEET on the skin. Travelers to rural areas in Africa and the West Indies should be aware that they may come in contact with ATBF tick vectors. Infection is more likely to occur in people who are traveling to rural areas or plan to spend time participating in outdoor activities.
To prevent tick bites:
- Treat clothing with appropriate permethrin products. Always follow label instructions.
- Wear light-colored long pants and long-sleeved clothing so that ticks are easier to spot before they attach to the skin.
- Tuck pant cuffs into your socks to keep ticks off your skin.
- Ticks may be carried into the house on clothing and gear (coats, packs, etc.); check your clothing and gear for any ticks and remove them if found.
- Ticks on clothing can be killed in the dryer on high heat for 10 minutes.
- Avoid wooded areas and overgrown brush by walking in the center of the trail.
- Remove brush, leaf litter, tall grasses, and backyard clutter from personal residences.
- After returning indoors, shower as soon as possible. Showering may help wash off unattached ticks and it is a good opportunity to do a tick check.
- Check for ticks on yourself, your children, and your pets after spending time outdoors.
- Staying on paths and trails
- Tucking trousers into boots or socks
- Wearing long-sleeved shirts
- Applying repellents with diethyltoluamide (DEET) to skin surfaces
DEET should be used cautiously in very young children because toxic reactions have been reported. Permethrin on clothing effectively kills ticks. Frequent searches for ticks, particularly in hairy areas and on children, are essential in areas where infections transmitted by ticks are common.
Engorged ticks should be removed with care and not crushed between the fingers because crushing the tick may result in disease transmission. The tick’s body should not be grasped or squeezed. Gradual traction on the head with a small forceps dislodges the tick. The point of attachment should be swabbed with alcohol. Petroleum jelly, lit matches, and other irritants are not effective ways to remove ticks and should not be used.
No practical means are available to rid entire areas of ticks. However, the number of ticks may be reduced in areas where it is common by making the environment less appealing to the animals that carry the ticks. For example, people can make areas less appealing to mice by removing wood piles and leaf litter and clearing tall grasses and brush around homes, especially play areas.
