Infection caused by Rickettsia

Causes

• Epidemic louse-borne typhus fever:

- caused by Rickettsia prowazeki

- the common type in Uganda which is transmitted to man (the reservoir) by lice

• Murine (endemic) typhus fever: caused by Rickettsia typhi (mooseri) and transmitted by rat fleas

- rats and mice are the reservoir

• Scrub typhus fever (mite-borne typhus): caused by R. tsutsugamushi and transmitted by rodent mites

Clinical features

• Louse borne typhus presents with

- headaches, fever, chills

- severe weakness

- general pains

- macular rash which appears on the 5th day on the rest of the body except the face, palms and soles

- toxaemia (usually pronounced)

• Murine typhus has a similar picture but is less severe

Differential diagnosis

• Any cause of fever, eg. malaria, HIV, UTI, typhoid, etc

Investigations

Blood: for Weil-Felix reaction

Management

• 7-10 day course or for 48 hours after resolution of fever

doxycycline 100mg every 12 hours

HC3

child >8yrs: 2mg/kg per dose

contraindicated in pregnancy

or chloramphenicol 500mg orally or IV

HC4

every 6 hours child: 15mg/kg per dose

Prevention

• Personal hygiene
• Destruction of lice and rodents