Several distinct rickettsiae cause the disease known as typhus in humans.
The disease is spread by ticks, mites, fleas, or lice, each agent having
a distinct epidemiology, but all causing a disease with signs similar to
a bad cold with fever lasting form one to several weeks, chills, headache,
and muscle pains, as well as a body rash. There is often a large painful
sore at the site of the bite and nearby lymph nodes are swollen and painful.
Epidemic typhus (European, Classic, Louse-borne)
Epidemic typhus is prevalent worldwide. It is an acute disease passed
from human to human by the body louse. Endemic foci of epidemic typhus exist
in highland populations in Africa and South America, but tourists are at
minimal risk of acquiring lice and disease.
The disease is characterized by high fever, intractable headache, and
rash. Temperature reaches 104° F in several days and remains high. Headache
is generalized and intense. On the 4th to 6th day, the rash develops and
spreads. Prostration is due to low blood pressure, may be followed by vascular
collapse. Fatalities are rare in children; mortality increases with age.
Tick typhus, actually a form of spotted fever, is not uncommon in travelers
who spend time trekking or on safari in Africa or the Indian subcontinent.
Trekkers in southern Africa may be at risk from cattle or wild-animal ticks.
Seek local advice on areas where ticks pose a danger and always check
your skin carefully for ticks after walking in a danger area such as a tropical
forest. A strong insect repellent can help, and serious walkers in tick
areas should consider having their boots and trousers impregnated with benzyl
benzoate and dibutylphthalate.
Scrub typhus (Mite-borne typhus)
Scrub typhus is spread by mites that feed on infected rodents and exists
mainly on Pacific islands and in southeast and east Asia. You should take
precautions if walking in rural areas in South-East Asia. Incidence is highest
during the spring and summer when the activity of humans brings them in
contact with mites seeking animal hosts.
Onset is sudden with fever, chills, headache, and generalized swelling
of lymph nodes. At onset of fever, a red lesion develops at the site of
the bite. High fever to 104 °F develops during the first week as well
as a severe headache. A cough is present during the first week of fever
and pneumonia may develop. A rash also develops on the torso often extending
to the arms and legs.
Murine typhus (Rat / flea typhus)
Murine typhus is relatively common throughout the world and is transmitted
by fleas. It is clinically similar to epidemic typhus, but milder. Highest
incidence of cases occurs during the summer months when rats and their fleas
are most active and abundant.
Symptoms include chills, headache and fever, lasting about 12 days.
Rash and other manifestations are similar to epidemic typhus.
Prevention, vaccination and treatment of typhus
Prompt removal of attached ticks and use of repellents to prevent tick
attachment provide the best preventions against tick typhus. Laundering
of louse-infested clothing is the most effective means to avoid person-to-person
spread of lice and prevent epidemic typhus. Precautions taken when walking
in rural areas and the use of insect repellents will help prevent tick and
Vaccination against typhus is not required by any country as a condition
for entry. Treatment of all forms of typhus is similar. Chloramphenicol,
doxycycline or other forms of tetracycline result in rapid resolution of
fever and relapses are infrequent.
Production of typhus vaccine in the United States has been discontinued
and there are no plans for commercial production of a new vaccine.