The death of an Anna University student at Government Kilpauk Medical College Hospital (KMCH) on September 18, 2026, due to scrub typhus has again brought attention to this bacterial infection. University authorities have started screening students for scrub typhus, along with dengue and leptospirosis. (The Times of India)

Intervention

What is Scrub Typhus?

Scrub typhus is a bacterial infection caused by the bacterium Orientia tsutsugamushi. It spreads through the bite of infected larval mites, commonly called chiggers. Importantly, scrub typhus is not mosquito-borne.

  • It is a major public health problem in South and Southeast Asia.
  • A 2021 systematic review described scrub typhus as a largely under-recognised public health problem in India.
  • Scrub typhus accounted for 25.3% of studies on acute undifferentiated febrile illness (AUFI).
  • Community seroprevalence was reported at 34.2%.
  • The disease can cause severe illness and many deaths.

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

What are the Symptoms?

Symptoms usually begin within 10 days of infection. The United States Centre for Disease Control and Prevention (CDC) lists the following symptoms:-

  • Fever and chills
  • Headache
  • Body aches and muscle pain
  • A dark, scab-like area called an eschar at the site of the chigger bite
  • Mental changes ranging from confusion to coma
  • Enlarged lymph nodes
  • Rash

Severe Complications

Timely treatment is important because untreated scrub typhus can lead to serious illness. Possible complications include:-

  • Acute respiratory distress syndrome (ARDS)
  • Shock
  • Meningitis
  • Kidney failure

These complications can be fatal. In India, scrub typhus has a high mortality rate, mainly because of late diagnosis and treatment.

How is Scrub Typhus Diagnosed?

Diagnosis can be delayed because its symptoms are similar to those of several other diseases. Blood tests can help confirm the infection. The tests mentioned are:-

  • IgM ELISA
  • PCR

How is Scrub Typhus Treated?

Scrub typhus is treated with antibiotics. The antibiotics mentioned are:

  • Doxycycline
  • Azithromycin

Treatment is effective when it is started on time. A trial conducted across seven centres in India and published in 2023 compared combination therapy with treatment using either doxycycline or azithromycin alone. The trial found that patients receiving doxycycline and azithromycin together had faster resolution of complications than those receiving either drug alone. The combination-therapy group also had lower frequencies of:-

  • Respiratory complications
  • Renal complications
  • Hepatic complications
  • Central nervous system complications

How Can Scrub Typhus be Prevented?

There is currently no vaccine for scrub typhus. The infection is also not contagious.

Where are Chiggers Found?

Chiggers live in areas with:-

  • Grass
  • Thick vegetation
  • Agricultural fields
  • Plant litter
  • Bare soil

They are found across rural areas of Asia and usually feed on small mammals such as:

  • Rats
  • Shrews

Preventive Measures

Protection from chigger bites can help reduce the risk of infection.

  • Wear protective clothing.
  • Use covered footwear.
  • Use insect repellent.
  • Keep surroundings clean and well maintained.
  • Reduce conditions that provide suitable mite habitats.

Importance of Early Diagnosis

Early diagnosis and prompt treatment can reduce complications and mortality. The 2021 review highlighted the need for:

  • Early diagnosis
  • Prompt treatment
  • Good surveillance
  • Appropriate control measures

Conclusion

Scrub typhus is a bacterial infection caused by Orientia tsutsugamushi and spread through the bite of infected chiggers. It is not a mosquito-borne or contagious disease. Symptoms generally begin within 10 days and may include fever, headache, muscle pain, rash and an eschar. Delayed treatment can lead to serious complications such as ARDS, shock, meningitis, and kidney failure. IgM ELISA and PCR can help confirm the infection, while doxycycline and azithromycin are used for treatment. Since there is currently no vaccine, preventing chigger bites, maintaining clean surroundings, and ensuring early diagnosis and prompt treatment remain important.