Signs and symptoms include fever, headache, muscle pain, cough, and gastrointestinal symptoms. More virulent strains of O. tsutsugamushi can cause hemorrhaging and intravascular coagulation. Morbilliform rash, eschar, splenomegaly, and lymphadenopathies are typical signs. Leukopenia and abnormal liver function tests are commonly seen in the early phase of the illness. Pneumonitis, encephalitis, and myocarditis occur in the late phase of illness. It has particularly been shown to be the most common cause of acute encephalitis syndrome in Bihar, India. Causes<unk>  is transmitted by some species of trombiculid mites ("chiggers", particularly Leptotrombidium deliense), which are found in areas of heavy<unk>  vegetation. The mites feed on infected rodent hosts and subsequently transmit the parasite to other rodents and humans. The bite of this mite leaves a characteristic black eschar that is useful to the doctor for making the diagnosis.<unk>  is endemic to a part of the world known as the tsutsugamushi triangle (after O. tsutsugamushi). This extends from northern Japan and far-eastern Russia in the north, to the territories around the Solomon Sea into northern Australia in the south, and to Pakistan and Afghanistan in the west. It may also be endemic in parts of South America. The precise incidence of the disease is unknown, as diagnostic facilities are not available in much of its large native range, which spans vast regions of equatorial jungle to the subtropics. In rural Thailand and Laos, murine and<unk>  account for around a quarter of all adults presenting to hospital with fever and negative blood cultures. The incidence in Japan has fallen over the past few decades, probably due to land development driving decreasing exposure, and many prefectures report fewer than 50 cases per year. It affects females more than males in Korea, but not in Japan, which may be because sex-differentiated cultural roles have women tending garden plots more often, thus being exposed to vegetation inhabited by chiggers. The incidence is increasing in the southern part of the Indian subcontinent and in northern areas around Darjeeling.
Scrub typhus
Murine typhus
Plague 
Flying squirrel typhus
Haverhill fever
Tomato fever
Rat-bite fever
North Asian tick typhus