Relapsing Fever What is Relapsing Fever? Relapsing Fever is a bacterial infectious illness caused by members of the genus Borrelia. Lice and ticks are the disease vectors. Louse-borne relapsing fever can be found in any place with lice, but it is more common in places with poor sanitary conditions. The incubation period of louse-borne Relapsing Fever is 2 to 14 days. Tick-borne Relapsing Fever is more common in tropical and sub-tropical regions such as Africa, South America and Middle-East. The incubation period of tick-borne relapsing fever is 2 to 9 days. The clinical symptoms include fever, chills, vomiting, muscle pain, liver and spleen enlargement. Fever and other symptoms will last for few days and then improve. If no treatment is given, fever and symptoms will recur about one week later. The disease is so named because of this recurrence phenomenon. The clinical symptoms of Louse-borne and Tick-borne Relapsing Fever are basically the same, except that they are less severe in Tick-borne Relapsing Fever. How does it spread? Louse-borne Relapsing Fever is transmitted by infected body lice. Lice bite will not transmit the bacteria to human body. However, the bacteria can enter the body through broken skin, eye and nasal mucosa. Tick-borne Relapsing Fever is transmitted by a type of tick called Ornithodoros. The bacteria enter the body through the bite of infected ticks. Infected ticks can be found on the bodies of rodents e.g., rats. How can you prevent? There is no vaccine for Relapsing Fever. To prevent getting the disease, avoid close contact with Relapsing Fever patients under isolation. Avoid also contact with rodents can reduce the chance of having tick bite. Boiling or chemicals can be used to disinsect clothes and living areas. Antibiotics can be used for prophylaxis if tick bite in epidemic area experienced. How is it treated? Relapsing Fever can be treated by penicillin or tetracycline.