Clinical Manifestations & Complications of Scrub Typhus

Introduction Scrub typhus, also known as tsutsugamushi disease, is an acute febrile illness caused by infection with Orientia tsutsugamushi and characterized by focal or disseminated vasculitis and perivasculitis, which may involve the lungs, heart, liver, spleen, and central nervous system (1,2,3).The symptoms are usually mild and the clinical course selflimited, with spontaneous recovery after a few days; however, some cases are more severe and protracted, and the disease may be fatal (1). The diagnosis of scrub typhus is based on the patient's history of exposure, the clinical features, and the results of serologic testing (1,4,5).The article provides a review of the clinical features and the complications of scrub typhus. Clinical Course The disease in humans results after the introduction of O tsutsugamushi through the skin by the bite of a larvalstage (chigger) trombiculid mite(1,5,6). It occurs in persons who engage in occupational or recreational behavior that brings them into contact with mite-infested habitats such as brush and grass. After a blood meal, the chigger detaches and matures into a nymph and subsequently into an adult. Person-to-person transmission of infection has not been reported (5). Periods of epidemics are influenced by the activities of the infected mite.After an incubation period that ranges from 6 to 21 days (usually, 10-12 days), the onset of disease is characterized by fever, headache, myalgia, cough, and gastrointestinal symptoms (1). The severity of the symptoms varies widely, depending on the susceptibility of the host, the virulence of the bacterial strain, or both. Physical The illness begins rather suddenly with shaking chills, high fever (104-105°F), myalgia, infection of the conjunctiva and eschar (resembling a cigarette burn) with tender regional lymphadenopathy. Less frequently, ocular pain, wet cough, malaise, and injected conjunctiva are present. A spotted rash on the trunk may be present. Patients experience abrupt onset of severe headache, loss of appetite. The classic case description includes an eschar at the site of chigger feeding, regional lymphadenopathy, and a maculopapular rash (1,4,5). The chigger bite is painless and may become noticed as a transient localized itch. Bites are often found at sites where skin surfaces meet or clothes bind, such as the axilla, groin, neck, waist, and inguinal area. Toward the end of the first week, approximately 35% of patients develop a centrifugal macular or maculopapular rash on the trunk, which may become papular. Later it may extend to the arms and the legs. There is usually tenderness from lymphadenopathy in the region of the bite wound or eschar. An eschar at the wound site is the single most useful diagnostic clue (4). An eschar is usually found on Caucasian and East Asian patients but is seen less frequently on South Asians, especially those who are dark skinned (7,8,9). The eschar begins as a small papule that SCRUB TYPHUS EMERGING THREAT CLINICAL VIEW POINT