Veterinary Epidemiology and Zoonosis

MURINE TYPHUS

Synonyms

• Flea-borne typhus fever, Endemic typhus fever, Urban typhus

Type of zoonosis

• Metazoonosis type I

Etiology

• It is caused by Rickettsia typhi

Reservoir and incidence

• Natural pathogen of rats and mice.
• Mammals including cats and their ectoparasites have been found infected.

Transmission

• Transmitted by flea or lice (Xenopsylla cheopis, Nosopsyllus fasciatus) to rodents or man.
• Humans are infected by flea bites and contamination of broken skin or conjunctiva by flea faeces.
• Domestic animals may transport the flea vector to humans.
• Inhalation of contaminated dust may be a route of infection.

Disease in animals

• The agent localizes in the brain and various organs but with no known lesions.

Disease in man

• Gradual onset of fever with severe headache, rigors, generalized pains and dry cough for about 2 weeks.
• A macular rash appears by about 5 days, first appearing on the trunk and lasting about six days.
• CNS manifestations are possible.
• Damage is caused to vascular endothelia by invasion of rickettsia, possibly leading to thrombosis and haemorrhage.
• Case fatality rate is 1-2% in untreated cases.

Diagnosis

• Serology by CFT or FAT.
• PCR

Treatment

• Tetracycline or chloramphenicol.

Prevention and control

• Control of wild rodents.
• Control of fleas in endemic areas.