what is typhus?

Answer 1

Typhus, any of a group of infectious diseases caused by microorganisms classified between bacteria and viruses, known as rickettsias. Typhus diseases are characterized by high fever and an early onset of rash and headache. They respond to antibiotic treatment with tetracycline and chloramphenicol and can be prevented by vaccination. Epidemic typhus, the most serious in the group, is caused by Rickettsia prowazeki, which is transmitted in the feces of body lice. It occurs in crowded, unsanitary conditions and has historically been a major killer in wartime. It occurs more commonly in cooler climates and seasons. Brill's disease, also called recrudescent typhus, is believed to be a milder recurrence of epidemic typhus. Endemic murine typhus is primarily a disease of rodents and is spread to humans by rat fleas. The symptoms are milder than those of epidemic typhus. Scrub typhus (Tsutsugamushi fever) is carried to humans by infected mites. It occurs primarily in East Asia and the Southeast Pacific islands.

Answer 2

Typhus is a name given to several similar diseases caused by Rickettsia bacteria. It comes from the Greek typhos, meaning smoky or hazy, describing the state of mind of those affected with typhus.

Rickettsia is endemic in rodent hosts, including mice and rats, and spreads to humans through mites, fleas and head, body, and pubic lice. The insects often flourish under conditions of poor hygiene, such as those found in prisons or refugee camps, amongst the homeless, or until the middle of the 20th Century, in armies in the field.

There are three types of typhus:

Epidemic typhus (also called "louse-bourne typhus") often causes epidemics, following wars and natural disasters. The causative organism is Rickettsia prowazekii, transmitted by the human body louse (Pediculus humanus corporis). Symptoms are headache, fever, chills, exhaustion, and rash. This form of typhus is also known as "prison fever" and as "ship fever", because it becomes prevalent in crowded conditions in prisons and aboard ships.
Endemic typhus (also called "flea-borne typhus" and "murine typhus") is caused by Rickettsia typhi, transmitted by fleas infesting rats, and, less often, Rickettsia felis, transmitted by fleas carried by cats or possums. Symptoms include headache, fever, chills, joint pain, nausea, vomiting, and cough.
Scrub typhus (also called "chigger-borne typhus") is caused by Orientia tsutsugamushi and transmitted by chiggers, which are found in areas of heavy scrub vegetation. Symptoms include fever, headache, muscle pain, cough, and gastrointestinal symptoms.
Symptoms common to all forms of typhus are a fever which may reach 39 °C (102 °F) and a headache. Definitive diagnosis can be obtained by serological testing ( the Weil-Felix test). Treatment is often with tetracycline or related antibiotics.

There are a number of other diseases caused by Rickettsiae, including Rocky Mountain spotted fever (also known as "Tick typhus"), Rickettsialpox and Boutonneuse fever. In tropical countries, typhus is often mistaken for dengue. In the past, typhus was sometimes referred to as Petechial Fever[1], but this term could also refer to other diseases.

Typhoid fever is a completely different disease caused by various strains of Salmonella, and should not be confused with typhus despite their similar-sounding names.