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.
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.
Typhus is a bacterial disease; there are two types termed endemic and epidemic.
Typhus has a long and deadly history, especially epidemic typhus.
Typhus is caused by bacteria. Rickettsia prowazekii causes epidemic typhus. Rickettsia typhi and, occasionally, R. felis cause endemic typhus and are transmitted to humans by vectors such as lice (mainly epidemic) and fleas (mainly endemic).
Risk factors include visiting or living in areas where rats, mice, and other animals have high populations (for example, disaster areas, poverty-stricken areas, refugee camps, jails) where vectors such as fleas and lice can carry the bacteria from the animals to infect humans.
Endemic typhus symptoms can include rash that begins on the body trunk and spreads, high fever, nausea, malaise, diarrhea, and vomiting; Epidemic typhus has similar but more severe symptoms, including bleeding into the skin, delirium, hypotension, and death.
Typhus is diagnosed by patient history, physical exam, and several tests (PCR, histological staining) based on immunological techniques. Some tests may need to be done in state or CDC labs.
The prognosis for endemic typhus is usually good to excellent, but the epidemic typhus prognosis can range from good, with early effective treatment, to poor, with the elderly often having the worst prognosis.
Both types of typhus can be reduced or prevented by good hygiene and clean living conditions that reduce or eliminate exposure to rats, mice, and other animals and the vectors that they carry (lice, fleas). There is no commercially available vaccine against either endemic or epidemic typhus.
Remove pet food, cover garbage containers, and trim vegetation around buildings to discourage rats and opossums from around your home. If you see live or dead opossums on your property, call your local animal control. Keep pet cats indoors as much as possible and consult your veterinarian about proper flea control on pets.