What is Scrub Typhus?

Scrub typhus, also known as Tsutsugamushi disease, is a form of typhus caused by the bacterium Orientia tsutsugamushi. The infection usually spreads through the bite of larval trombiculid mites. These mites are native to Southeast Asia and Japan, where scrub typhus is most often found. Symptoms can include headache, high fever and coughing, as well as a rash that may cover the torso and limbs. Complications can be severe and life threatening, and though it can be fatal when left untreated, antibiotics can be used to cure it.

Tsutsugamushi disease is commonly called scrub typhus because the mites that spread it are most often found in scrub-land areas. These mites are indigenous to Southeast Asia and Japan, and they typically cause the highest rates of infection during the rainy part of the year. As many as five percent of those who live in Southeast Asia or Japan will contract this bacterial disease. While scrub typhus does typically leave its survivors with some level of immunity, this immunity generally only lasts about one to three years.

This disease can incubate in the body for six to 21 days, though it usually incubates for a period of 10 to 12 days. Symptoms generally appear suddenly, and include a high fever of about 104 degrees Fahrenheit (40 C), chills, headache, and lymph node swelling. About half of those infected will develop an open sore at the site of infection.

A rash may appear during the first week of the disease process. This rash can cover the entire torso and even spread to the limbs. Most patients develop a cough during the first week of the disease process, which can devolve into pneumonitis during the second week. Complications of scrub typhus can include meningoencephalitis, hepatitis, pneumonitis, and myocarditis. Failure of one or more major organs is also possible.

While scrub typhus can be a life-threatening infection, not all people who contract it die without treatment. Without treatment, symptoms may begin to resolve after two weeks. Once the high fever begins to recede, recovery is generally expected and usually occurs quickly.

With treatment, symptoms can begin to resolve in as little as 36 hours. Antibiotics are generally administered to treat scrub typhus. Doxycycline is considered the drug of choice. Azithromycin and chloramphenicol may be administered to treat more severe infections, especially when those caused by drug-resistant strains of Orientia tsutsugamushi.