scrub typhus, an acute febrile disease caused by several strains of the species Orientia tsutsugamushi (formerly Rickettsia tsutsugamushi) and transmitted from infected rodents to humans by mites. It is found in Asia, India, northern Australia, and the western Pacific islands. The clinical course ranges from mild to severe and is characterized by a necrotic papule or black eschar at the site of the lesion caused by the bite of the small arachnid. Tender enlarged regional lymph nodes, fever, severe headache, eye pain, muscle aches, and a generalized rash usually occur. In severe cases the myocardium and the central nervous system may be involved. The DNA-PCR and indirect fluorescent antibody tests are useful in diagnosis. Treatment with antibiotics, such as chloramphenicol, doxycycline, or azithromycin, has reduced the mortality rate to nearly zero. Person-to-person transmission is not known to occur. No effective vaccine is available, and second attacks are common because of antigenic differences in various strains of rickettsiae. Prevention includes avoiding mite-infested terrain, reducing the rodent population, destroying scrub vegetation, and using insect repellents. Also called Japanese flood fever, Japanese river fever, mite typhus, tropical typhus, tsutsugamushi disease. Compare Q fever, Rocky Mountain spotted fever, typhus.
