Relapsing fever, endemic A68.1

Borrelia spp, esp.

• B. duttonii and B. crocidurae (Africa)
• B. hermsii, B. turicatae, B. parkeri (North America)
• B. venezuelensis, B. neotropica (Central and South America)
• B. persica (Near and Middle East, Asia)
• B. hispanica (Iberian Peninsula, North Africa)

Pathogen reservoir: humans (Africa), ticks, rodents, poultry, dogs, wild boar

Vector: leather tick (Ornithodorus moubata).

Tropical Africa, Spain, North Africa, Arabian Peninsula, Middle East, South and Central Asia, North and South America. In Central Europe relapsing fever is very rare. If it occurs, it is usually a travel sickness or infected migrants from North East Africa.

Incubation period 5-15 days. Occasionally, an ulcerated nodule up to the size of a pea can be detected at the injection site, which may be covered with black crusts (tache noir). Massive bacteremia and infestation of almost all organs. The degree of spirochaemia determines the clinical severity. In contrast to malaria, the fever attacks last 2-4 days and are interrupted by fever-free intervals of 3-6 days. The fever-free intervals increase in duration as the disease progresses. Relapses occur about two to ten times, with the severity of the disease decreasing. Immunity up to 1 year after infection. The most common cause of death is myocarditis.

A characteristic feature (in about 60% of infected persons) towards the end of the first fever period is a small macular or small papular, petechial exanthema (tendency to bleed). Damage to the vascular endothelia, bleeding tendency and organ necrosis determine the course of the disease. The skin changes no longer occur after the first period.

Complications include a strong bleeding tendency (epistaxis, conjunctival bleeding, hemorrhages of the gastrointestinal tract, lungs, urinary tract and CNS), nephritis, liver failure, myocarditis and sepsis with disseminated intravascular coagulation.

Pathogen detection in the blood (smear, thick drop, dark field microscopy). Serology (ELISA, CFT, agglutination). If necessary, detection in animal experiments. A cultural cultivation of Borrelia bacteria is possible under special culture conditions.

Blood count: neutrophil leukocytosis, inflammation parameters significantly increased.

Doxycycline (e.g. Doxycycline Heumann) 2x/d 100 mg p.o. or tetracycline (e.g. Tetracycline Wolff) 3-4x/d 500 mg p.o. for 14 days. Infants should receive penicillin instead of tetracycline.

Caution: Jarisch-Herxheimer reaction

1. Bissett JD et al (2018) Detection of Tickborne Relapsing Fever Spirochete, Austin, Texas, USA. Emerg Infect Dis 24:2003-2009.
2. Mafi N et al (2019) Tick-Borne Relapsing Fever in the White Mountains, Arizona, USA, 2013-2018. Emerg Infect Dis 25:649-653.
3. Naddaf SR et al. (2015) Tickborne relapsing fever in southern Iran, 2011-2013. Emerg Infect Dis 21:1078-1080 .