What is scrub typhus | Explained

On September 18, 2026, an Anna University student succumbed to scrub typhus at Government Kilpauk Medical College Hospital (KMCH). This incident has once again highlighted the dangerous nature of this bacterial infection. The university has initiated screenings for scrub typhus along with dengue and leptospirosis in students. Scrub typhus is caused by the bacterium Orientia tsutsugamushi and is transmitted through the bite of infected larval mites or chiggers, not mosquitoes. It is prevalent in South and Southeast Asia and often goes unrecognized.

A 2021 review indicated that scrub typhus is under-recognized in India, accounting for 25.3% of acute undifferentiated febrile illness (AUFI) cases, with a seroprevalence of 34.2%. The disease leads to severe morbidity and mortality, with recent studies in Karnataka, Andhra Pradesh, and Tamil Nadu identifying it as the primary cause of acute encephalitis syndrome (AES) in southern India.

Symptoms appear within 10 days of infection and include fever, chills, headache, body aches, mental changes, enlarged lymph nodes, and a rash at the bite site. Without prompt treatment, complications such as ARDS, shock, meningitis, and kidney failure can occur, leading to death.

In India, the mortality rate from scrub typhus is high due to late diagnosis and treatment. Swift diagnosis through blood tests like IgM ELISA or PCR is crucial, followed by antibiotic treatment with doxycycline or azithromycin. A 2023 trial demonstrated that combination therapy of doxycycline and azithromycin provided better outcomes than monotherapy, reducing the risk of respiratory, renal, hepatic, and central nervous system complications.

Currently, there is no vaccine for scrub typhus, and the infection is not contagious. Prevention involves protective clothing, footwear, insect repellent, maintaining cleanliness, and avoiding areas with high mite populations. Early diagnosis and prompt treatment are essential to mitigate complications and mortality. Establishing robust surveillance and control measures is urgently required.