Clinical manifestations of scrub typhus

Abstract

The mite-borne rickettsial zoonosis scrub typhus is widely prevalent in parts of Southeast and Far East Asia, and northern Australia. The disease is an acute febrile illness, associated with rash and often an eschar, which responds dramatically to treatment with antibiotics. In some cases it results in a serious illness leading to multiple organ involvement and death. The disease manifestations are thought to result from a systemic vasculitis, caused by both direct effects of the organisms as well as an exaggerated immune response, although little is understood about its pathogenesis. A wide spectrum of clinical manifestations, affecting nearly every organ system, have been described with scrub typhus. Some of these manifestations are serious and life threatening. In this systematic review, we summarise the typical and atypical manifestations of scrub typhus reported in the literature. Awareness of these unusual manifestations will hopefully guide clinicians towards diagnosing the condition early, and initiating early appropriate antibiotics and other supportive measures.

The estimated burden of scrub typhus in Thailand from national surveillance data (2003-2018)

“…The incubation period ranges from 6 to 21 days and clinically, scrub typhus is characterised by fever, eschar, maculo-papular rash, headache, cough, nausea, vomiting, myalgia and lymphadenopathy [18]. The eschar at the site of the mite bite is the most characteristic feature but is not always present, being dependent on the degree of pre-existing immunity to the infecting Orientia tsutsugamushi strain [19,20].…”

“…The eschar at the site of the mite bite is the most characteristic feature but is not always present, being dependent on the degree of pre-existing immunity to the infecting Orientia tsutsugamushi strain [19,20]. Severe disease may present with complications affecting multiple organ systems [18]. The standard antibiotic treatment is doxycycline for 7 days with alternative options including tetracycline, chloramphenicol, azithromycin and rifampicin [21,22].…”

Rickettsia felis identified in two fatal cases of acute meningoencephalitis

“…Because neither case responded to standard TB therapy for the region, the possibility of an alternate etiology was considered. Hypoglycorrhachia, present in both cases, as well as lymphocytic pleocytosis and increased protein, in Case 1, have been noted in rickettsial infections [19]. R. felis has been reported as a cause of neurological disease in Mexico [9] and Sweden [10,11], where it has been identified from CSF.…”

A woman with persistent fever and a skin lesion

“…Skin lesion near left popliteal fossa myalgia. 5,6 A macular rash involving the trunk and limbs may develop towards the end of the first week. Lymphadenopathy and splenomegaly may occur.…”