Scrub Typhus

Scrub typhus, also called tsutsugamushi disease, is a bacterial infection caused by *Orientia tsutsugamushi* ^[1]. The disease is classified among bacterial zoonoses and is associated with arthropod-vector exposure rather than direct person-to-person spread in the evidence provided ^[2]. Source-backed detail on finer microbiologic or taxonomic subtyping is not yet available in the supplied material ^[1][2].

The illness is described as an acute febrile disease that generally presents with non-specific symptoms and signs, which can make it difficult to recognize clinically ^[2]. Reported clinical severity ranges from sub-clinical infection to organ failure and fatal disease ^[2]. One review notes that scrub typhus can cause severe multiorgan failure, and that case fatality may reach 70% without appropriate treatment ^[1]. Deaths have been attributed in the literature to late presentation, delayed diagnosis, and drug resistance ^[2].

Scrub typhus is reported as widespread across Asia and the Pacific Islands, with particular emphasis on the Asia-Pacific area as a major public-health burden ^[2][1]. One review estimates that it threatens one billion people globally and causes illness in about one million people each year ^[1]. It has also been described as an important military disease historically, causing thousands of cases in the Far East during the Second World War ^[2]. The evidence base is described as incomplete, with sporadic epidemiologic data in endemic areas and a recognized gap in public-health information ^[1].

The supplied sources characterize scrub typhus as a zoonosis and place it among bacterial zoonoses acquired via arthropod vectors ^[2]. No more specific vector, reservoir, or exposure pathway is stated in the provided snippets, so source-backed detail beyond arthropod-mediated transmission is not yet available ^[2].

The supplied sources explicitly identify residents of endemic regions in Asia and the Pacific as the main affected populations, and historical reports highlight military populations during the Second World War ^[2]. Beyond this, source-backed detail on specific high-risk age groups, occupational groups, or comorbidities is not yet available in the provided snippets ^[1][2].

The source material indicates that prevention and control are important issues in long-standing endemic areas and in newly recognized foci of infection, but it does not provide detailed control measures in the snippets supplied ^[1]. It also notes that the antigenic heterogeneity of *O. tsutsugamushi* precludes generic immunity and allows reinfection, which is relevant to prevention planning ^[1]. Source-backed detail on vaccines, chemoprophylaxis, or specific exposure-control guidance is not yet available ^[1].

In surveillance settings, scrub typhus should be read as an under-recognized cause of acute febrile illness in Asia-Pacific and other endemic or newly recognized foci ^[1][2]. The literature emphasizes that public-health importance is underestimated because clinical diagnosis is difficult and laboratory methods are lacking in many geographic areas ^[2]. Surveillance data are therefore likely to undercount disease burden, and the available epidemiology should be interpreted as incomplete rather than definitive ^[1][2].

1. 1 Xu G et al. A review of the global epidemiology of scrub typhus. PLoS Negl Trop Dis. 2017 Nov. PMID: 29099844. doi: 10.1371/journal.pntd.0006062. PubMed: https://pubmed.ncbi.nlm.nih.gov/29099844/
2. 2 Chikeka I et al. Neglected bacterial zoonoses. Clin Microbiol Infect. 2015 May. PMID: 25964152. doi: 10.1016/j.cmi.2015.04.022. PubMed: https://pubmed.ncbi.nlm.nih.gov/25964152/
3. 3 Mahajan SK et al. Scrub typhus. J Assoc Physicians India. 2005 Nov. PMID: 16515236. PubMed: https://pubmed.ncbi.nlm.nih.gov/16515236/
4. 4 Scrub-Typhus. The American Journal of Tropical Medicine and Hygiene. 1945. doi: 10.4269/ajtmh.1945.s1-25.481. DOI: https://doi.org/10.4269/ajtmh.1945.s1-25.481
5. 5 Scrub typhus. SpringerReference. None. doi: 10.1007/springerreference_42481. DOI: https://doi.org/10.1007/springerreference_42481
6. 6 Scrub typhus. Oxford Textbook of Medicine. 2010. doi: 10.1093/med/9780199204854.003.070640_update_001. DOI: https://doi.org/10.1093/med/9780199204854.003.070640_update_001

ICD-10

A75.3

ICD-11

1C30.2

Total cases

278K

Peak month

2016-01

Coverage

5 reporting countries · 2020-01-01 → 2026-05-01