African Tick Bite Fever
African tick bite fever (ATBF) is caused by a bacterium called Rickettsia
africae. It was first identified in southern Africa in 1911. The
bacterium is transmitted by Amblyomma ticks, primarily A. variegatum
(the tropical bont tick) and A. hebraeum (the southern African bont
tick). R. africae has been detected in 15 African countries and has
been introduced into the West Indies along with A. variegatum ticks.
 
Amblyomma variegatum and Amblyomma hebraeum
Symptoms generally appear 5-7 days (up to 10) after a tick bite and include
fever, nausea, fatigue, headache, muscle pain, and neck stiffness. There
is generally an inoculation eschar at the site of the tick bite that consists of
a black crust surrounded by a red halo. Some people have multiple eschars
due to multiple bites. Complications seem to be rare and there are no
known fatal cases.
Travelers to sub-Saharan Africa or the West Indies are at risk of developing
the disease. 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.
Prevention of Tick-borne Diseases
Resources
Jensenius M, Fournier P, Kelly P, Myrvang B, Raoult D. African tick bite
fever. The Lancet Infectious Diseases. 2003; 3:557-564.
Raoult D, Fournier P, Fenollar F, Jensenius M, et al. Rickettsia africae,
a tick-borne pathogen in travelers to sub-Saharan Africa. New England Journal of
Medicine. 2001; 344(20):1504-1510.
Kelly P. Rickettsia africae in the West Indies. Emerging
Infectious Diseases. 2006; 12(2): 224-226.
http://www.cdc.gov/ncidod/EID/vol12no02/05-0903.htm
Cazorla C, Socolovschi C, Jensenius M, Parola P. Tick-borne Diseases:
Tick-borne Spotted Fever Rickettsioses in Africa. Infect Dis Clin N Am.
2008; 22:531-544.
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