What is scrub typhus | Explained

You don’t have any Active Subscription.

Account subscription benefits alongside Premium Stories, Editorials, Opinions and more. Unlock these with Subscription

A 2021 systematic review noted that scrub typhus, a common acute febrile illness, is “a grossly under-recognised public health problem in India. (Representational image) | Photo Credit: Getty Images/iStockphoto

The death of an Anna University student at Government Kilpauk Medical College Hospital (KMCH) on Friday (September 18, 2026), due to scrub typhus, has once again brought this bacterial infection to the fore. University authorities have said they have started screening students for scrub typhus as well, along with dengue and leptospirosis

Scrub typhus is a bacterial infection caused by the bacterium Orientia tsutsugamushi. It is spread by the bite of infected larval mites or chiggers -- it is not a mosquito-borne disease.

Scrub typhus is a major public health burden in South and Southeast Asia. A 2021 systematic review noted that scrub typhus, a common acute febrile illness, is “a grossly under-recognised public health problem in India.” It stated that the proportion of scrub typhus among acute undifferentiated febrile illness (AUFI) studies was 25.3%, and community seroprevalence was 34.2%. The review also noted that the disease causes severe morbidity and accounts for a large number of deaths, with its bueden “underappreciated.”

A 2025 multi-centre study of 587 children with acute encephalitis syndrome (AES) from Karnataka, Andhra Pradesh, and Tamil Nadu revealed that scrub typhus is now the most common infectious cause of AES in southern India.

Symptoms usually begin within 10 days of infection. The United States Centre for Disease Control and Prevention (CDC) lists symptoms of scrub typhus as: fever and chills, headache, body aches and muscle pain, a dark, scab-like region at the site of the chigger bite (also known as eschar), mental changes ranging from confusion to coma, enlarged lymph nodes and a rash.

Timely treatment is critical. If left untreated, severe illness from scrub typhus infection can lead to acute respiratory distress syndrome (ARDS), shock, meningitis and kidney failure, which can be fatal, notes a research paper, Incidence of Scrub Typhus in Rural South India published in The New England Journal of Medicine last year.

In India, there is a high mortality of scrub typhus, primarily due to late diagnosis and treatment.

Since the symptoms of scrub typhus are common to those of several other diseases, diagnosis is often delayed. A blood test (IgM ELISA or PCR) can help confirm the diagnosis.

Scrub typhus should be treated with the antibiotics doxycycline or azithromycin. If the treatment is begun in time, it is effective. Results of a trial carried out in seven centres in India, published in 2023, in which patients were randomly assigned to receive a combination therapy of doxycycline and azithromycin, showed faster resolution of complications compared with two other arms where patients were given monotherapy with either doxycycline or azithromycin. The frequencies of respiratory, renal, hepatic, and central nervous system complications were lower in the combination-therapy group than in either of the monotherapy groups. 

There is no vaccine as yet for scrub typhus. The infection is not contagious.

Chiggers live in areas with lots of grass, thick vegetation, agricultural fields, plant litter and bare soil across rural areas of Asia, and usually feed on small mammals such as rats and shrews.

Keeping oneself safe from bites through protective clothing, covered footwear and the use of insect repellent may help. Ensuring surroundings are clean and well maintained can also go some way towards reducing mite habitats.

“Early diagnosis and prompt treatment can significantly reduce complications and mortality. Establishing good surveillance and instituting appropriate control measures are urgently needed,” the 2021 review notes.

Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.