Typhus, also known as typhus fever, is a group of infectious diseases caused by specific types of bacteria. There are three main types of typhus:

• Epidemic typhus : Caused by the bacterium Rickettsia prowazekii and spread by body lice. It typically occurs in outbreaks under poor sanitary and crowded conditions.
• Scrub typhus : Caused by Orientia tsutsugamushi and spread by chiggers (larval mites). It is commonly found in Southeast Asia, Japan, and northern Australia.
• Murine typhus : Caused by Rickettsia typhi and spread by fleas, commonly found in tropical and subtropical regions.

Common symptoms of typhus include fever, headache, rash, muscle pain, and sometimes symptoms like nausea or cough. The diseases are transmitted to humans through bites from infected lice, fleas, or mites, depending on the type of typhus. Typhus is treatable with antibiotics such as doxycycline, and prevention involves reducing exposure to the vectors that spread the bacteria. Although historically it caused significant illness and death, now it is rare in places with good hygiene and sanitation. The name "typhus" comes from a Greek word meaning "hazy" or "smoky," reflecting the state of mental confusion that can occur in infected individuals. Typhus and typhoid fever are distinct diseases caused by different bacteria.