Relapsing fever: Treatment, symptoms, advice and help

Organism

This is an infection caused by a spiral bacterium called Borrelia, which results in a relapsing pattern of fever with illness lasting 3 to 6 days then settling for 7 to 10 days before recurring. The relapsing pattern of illness is caused by conflict between the immune system which is trying to control the infection and the organism which is altering its appearance to the immune system. Thus at the end of each period of illness, the organism is cleared from the blood, but hides in body organs, altering its appearance before recurring in the blood with the recurrence of fever and other symptoms. The duration and severity of episodes reduces progressively with each relapse. Several species of Borrelia can cause relapsing fever, although the louse borne type is always caused by Borrelia recurrentis.

Mode of Transmission

Relapsing fever can be transmitted either by lice or by soft ticks. Louse borne infections can cause large scale epidemics, particularly in times of catastrophe such as wars or famine. The last great epidemic of louse borne relapsing fever was in the second world war in North Africa and Europe. It is estimated that around 50,000 people died as a result of this epidemic. Infection is transmitted when an infected louse is crushed contaminating the bite wound or a cut or graze on the skin. Tick borne cases generally occur sporadically but outbreaks can also occur, particularly in the summer months. Tick borne infection usually occurs in wild animals such as rabbits, squirrels, rats and owls, humans only becoming infected when they venture into rural tick infested regions. Ticks transmit Borrelia directly via the bite, and also through contamination of cuts by their faeces. Ticks tend to bite at night and need only attach for a very short time (5 to 20 minutes) to transmit infection. Thus the tick bite may go unnoticed. The last outbreak of tick borne relapsing fever occurred in 1973 when over 60 people staying in log cabins in Arizona were infected.

Regions Affected

Louse borne infection still occurs in some parts of Asia, the highlands of Central and Eastern Africa and the Andes region of South America. The occurrence of relapsing fever is dependent mainly on socio-economic factors such as overcrowding and poor hygiene. Tick borne relapsing fever occurs throughout tropical Africa, North Africa, Saudi Arabia, Iran, India, Central Asia, South America and the western United States and Canada. Cases have also been reported from Spain.

Prevention

Louse borne relapsing fever is prevented by controlling lice, by improving washing facilities, promptly treating infested people and their bedding and clothes, and also treating with insecticides for people at risk. Antibiotics may be used to prevent infection after possible exposure.

The risk of developing tick borne relapsing fever can be reduced by removing ticks after exposure to tick infested areas, controlling ticks on dogs and controlling rodents in and near houses which may bring ticks into close proximity with humans.

Immunisation

None available.

Symptoms and Signs

The incubation period is thought to be 1 to 2 weeks, but may be difficult to determine since exposure to lice may occur over a prolonged period, and tick bites often go unnoticed. Patients present with sudden onset fever, shakes, headache, muscle and joint aches, lethargy and cough. They may develop a rash towards the end of the feverish period with evidence of bleeding and bruising. The liver and spleen are enlarged and the eye becomes inflamed with the potential for loss of vision. One-third of patients will develop brain involvement with muscle weakness, reduced consciousness or fits. The heart, liver and lungs may be<