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- Typhus facts
- What is typhus? Are there different types of typhus?
- What is the history of typhus?
- What causes typhus? How is typhus transmitted?
- What are typhus risk factors?
- What are typhus symptoms and signs?
- How is typhus diagnosed?
- What is the treatment for typhus?
- What is the prognosis of typhus?
- Can typhus be prevented?
- Where can people get more information about typhus?
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What is typhus? Are there different types of typhus?
Typhus is a disease caused by bacteria (mainly Rickettsia typhi or R. prowazekii). There are two major types of typhus: endemic (or murine typhus) and epidemic typhus. The bacteria are small and very difficult to cultivate; originally they were thought to be viruses. The disease occurs after bacteria (Rickettsia spp.) are transferred to humans usually by vectors such as fleas or lice that have acquired the bacteria from animals such as rats, cats, opossums, raccoons, and other animals. Endemic typhus (mainly caused by R. typhi) is also termed murine typhus and "jail fever." "Endemic typhus" also means that an area or region has an animal population (usually mice, rats, or squirrels) that has members of its population continually infected with R. typhi that through flea vectors can incidentally infect humans. Epidemic typhus (caused by R. prowazekii) is the more severe form of typhus. It has also been termed recrudescent or sporadic typhus. "Epidemic typhus" also means that a few animals, (usually rats) via lice vectors, can incidentally infect large numbers of humans quickly when certain environmental conditions are present (poor hygiene, poverty, crowded human living conditions) with the more pathogenic R. prowazekii. Epidemic typhus has a milder form termed Brill-Zinsser disease, which occurs when R. prowazekii bacteria reactivate in a person previously infected with epidemic typhus.
There is some confusion surrounding the term "typhus." Many people occasionally equate typhus with typhoid (typhoid fever), which is incorrect. There is confusion for multiple reasons. Both diseases have in common the symptom of high fever, and the major species of Rickettsia that causes endemic typhus is still termed "typhi." However, the causes, transmission, pathology, and treatment of these diseases are quite different. Salmonella spp. causes typhoid fever, and this is unrelated to Rickettsia. Additionally confusing is the term "scrub typhus," which refers to a related but different disease. This disease is related to typhus but is caused by a different genus and species of bacteria and is transmitted by a different vector (see the causes section below). The aim of this article is to inform the reader about the two major worldwide variations of typhus, endemic and the more severe epidemic typhus.