What is scrub typhus | Explained

On September 18, 2026, a student from Anna University passed away at Government Kilpauk Medical College Hospital (KMCH) due to scrub typhus. This bacterial infection has once again come to the forefront. The university has since initiated screening for scrub typhus, dengue, and leptospirosis among students.

Scrub typhus is caused by the bacterium Orientia tsutsugamushi and is transmitted through the bite of infected larval mites, also known as chiggers. It is not a mosquito-borne disease. Despite being a significant public health concern in South and Southeast Asia, scrub typhus is often under-recognized.

A 2021 study revealed that scrub typhus accounts for 25.3% of acute undifferentiated febrile illness (AUFI) cases in India and has a community seroprevalence of 34.2%. The same study found that scrub typhus is now the most common infectious cause of acute encephalitis syndrome (AES) in southern India, affecting children in Karnataka, Andhra Pradesh, and Tamil Nadu.

Symptoms of scrub typhus typically appear within 10 days of infection and include fever and chills, headache, body aches and muscle pain, a scab-like lesion at the bite site, mental changes, enlarged lymph nodes, and a rash. Untreated, severe illness can lead to acute respiratory distress syndrome, shock, meningitis, and kidney failure, which can be fatal.

Diagnosis can be challenging as symptoms overlap with other diseases, often resulting in delayed detection. A blood test, such as IgM ELISA or PCR, can confirm the diagnosis. Prompt treatment with antibiotics like doxycycline or azithromycin is crucial for effective recovery.

A 2023 trial in India found that a combination therapy of doxycycline and azithromycin led to faster resolution of complications compared to monotherapy with either antibiotic. There is currently no vaccine for scrub typhus, and the infection is not contagious. Prevention involves avoiding chigger bites by wearing protective clothing, using insect repellent, and maintaining clean surroundings to minimize mite habitats. Early diagnosis and treatment are essential to significantly reduce complications and mortality rates.