Several distinct Rickettsiae species cause typhus fevers in humans. Each agent produces disease with a distinct epidemiology, but all cause illness, usually with fever, headache, or rash, or a combination of these. Treatment of all forms of typhus is similar and includes administration of appropriate antibiotics (for example, the tetracycline class) and supportive care; relapses are infrequent. The body louse passes epidemic typhus from person to person. Endemic, or murine, typhus occurs worldwide and is transmitted by rat fleas. Different tickborne typhus fevers occur in Europe, Africa, the Americas, Australia, and Asia. Scrub typhus, transmitted by rodent mites, occurs in a large area from the Indian subcontinent to Australia and in much of Asia, including Japan, China, Korea, and parts of Russia.

Occurrence

Endemic typhus is common year round in the tropics. In temperate areas, it occurs during the summer months when rats and their fleas are most active and abundant. Outbreaks of epidemic typhus are rare except during periods when normal hygiene is disrupted, as in refugee camps arising from wars or natural disasters. It also occurs in some populations living in higher elevations during the colder months when louse-infested clothing is not laundered and person-to-person spread of lice is common. Scrub typhus can occur throughout the year, but is dependent on temperature and rainfall (which affect the prevalence of the mites that transmit the disease).

Risk for Travelers

Endemic typhus occurs often in people frequenting rat-infested buildings and houses in harbor or riverine areas. Foci of epidemic typhus exist in impoverished and dislocated populations in the highlands of some parts of Africa and South America, but travelers are rarely at risk of acquiring lice and disease. Scrub typhus and tick typhus occur in people who engage in occupational or recreational behaviors that bring them inadvertently in contact with mite- or tick-infested habitats that harbor the rodent hosts of these arthropods. Tick typhus infections, often called spotted fevers, occur occasionally in travelers who spend time in nature trekking or camping, or on safari.

Preventive Measures

Vaccine

Vaccination against any of the typhus fevers is not required by any country as a condition for entry. Although experimental vaccines have been developed for the typhus fevers, no commercially licensed vaccines are produced presently in the United States.

Other

Travelers should be advised that prevention is based on avoidance of vector-infested habitats, use of repellents and protective clothing when exposed, prompt detection and removal of arthropods on clothing and skin, and attention to hygiene. Disease management should focus on early detection and proper treatment to prevent severe complications of these illnesses.

© Center for Disease Control

Credits: National Center for Infectious Diseases