Typhus

  • Medical Author:
    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

  • Medical Editor: Mary D. Nettleman, MD, MS, MACP
    Mary D. Nettleman, MD, MS, MACP

    Mary D. Nettleman, MD, MS, MACP

    Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.

Bacterial Infections 101 Pictures Slideshow

Quick GuideTravel Health Pictures Slideshow: Vaccines & Preventing Diseases Abroad

Travel Health Pictures Slideshow: Vaccines & Preventing Diseases Abroad

What causes typhus? How is typhus transmitted?

The causes of typhus are small Gram-negative coccobacilli-shaped bacteria, members of the genus Rickettsia that are intracellular parasites of many animals and utilize the components within the cell to survive and multiply. They are difficult to cultivate because they usually only grow within cells they infect. Occasionally, the bacteria may become dormant in infected cells, and years later, again begin to multiply (causing Brill-Zinsser disease). Generally, typhus follows an animal (rat, mouse) to vector (louse, flea) cycle. Humans are incidentally infected usually when the vectors come in close proximity to humans. The two Rickettsia spp. responsible for the two main types of typhus are R. prowazekii, the cause of epidemic typhus, and R. typhi, the cause of endemic typhus. However, R. felis, another species usually found in cat and cat fleas, has been linked to people with endemic typhus also. Epidemic typhus is usually spread or transmitted to humans from body lice (Figure 1) feces contaminated with R. prowazekii or occasionally from animal droppings contaminated with these bacteria. Endemic typhus is usually transmitted to humans by flea feces or animal droppings containing R. typhi or R. felis. The flea or louse bite causes itching and scratching and may allow the bacteria to enter the scratch or bite area in the skin. Indirect person-to-person transmission can occur if lice or fleas infect one person who develops the disease and then the infected lice or fleas move from person to person by direct contact or via shared clothing. In general, head lice that differ from body lice do not transmit Rickettsia.

Photo of a body louse and larvae
Fig. 1: Photo of a body louse and larvae; SOURCE: World Health Organization
Medically Reviewed by a Doctor on 11/23/2015

Subscribe to MedicineNet's Newsletters

Get the latest health and medical information delivered direct to your inbox!

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

VIEW PATIENT COMMENTS
  • Typhus - Causes

    What was the possible cause of your typhus infection?

    Post View 1 Comment
  • Typhus - Symptoms and Signs

    What were the symptoms and signs you experienced with your typhus infection?

    Post
  • Typhus - Diagnosis

    Discuss the events that led to a diagnosis of typhus.

    Post
  • Typhus - Prevention

    Please share your tips and suggestions for preventing a typhus infection.

    Post

Health Solutions From Our Sponsors