Scrub typhus is a potentially serious bacterial infection caused by Orientia tsutsugamushi, which is transmitted to humans through the bite of infected chigger mites (larval mites). Although it may sound unfamiliar to many, scrub typhus fever is common in rural areas of Asia, including India, especially during the monsoon and post-monsoon seasons. This illness can escalate quickly if left untreated, making early recognition crucial.
In this article, we’ll explore in depth what are the symptoms of scrub typhus, how it progresses, and when you should seek medical care. This guide will also help raise awareness about this neglected tropical disease, which affects thousands of people annually.
What is Scrub Typhus?
Scrub typhus is a rickettsial disease caused by the bacterium Orientia tsutsugamushi, which is passed to humans by the bite of a chigger mite. These mites are found in vegetation-rich areas like rice fields, forests, and grasslands. The infection is most common in regions called the “tsutsugamushi triangle,” which includes India, parts of Southeast Asia, China, and northern Australia.
Once infected, a person may develop symptoms within 6 to 21 days. If untreated, the disease can lead to serious complications such as multi-organ failure, pneumonia, encephalitis, and even death.
What Are the Symptoms of Scrub Typhus?
Let’s address the main question: What are the symptoms of scrub typhus?
Symptoms typically begin 6 to 10 days after the bite of an infected chigger. While the signs can vary from person to person, the most common symptoms include:
1. High Fever
Fever is usually the first and most prominent symptom. It starts abruptly and can range from 101°F to 104°F or higher. Unlike a regular viral fever, this one tends to persist and worsen over time if not treated.
2. Severe Headache
A pounding headache, often localized to the front of the head or temples, is another frequent complaint. This is usually accompanied by muscle aches and body pain, which can be debilitating.
3. Eschar (Black Scab)
This is a classic symptom but may not appear in every patient. An eschar is a black, crusty scab that forms at the site of the mite bite. It resembles a cigarette burn and is considered a diagnostic clue for scrub typhus. However, it may be hidden in areas like the groin, armpits, under the breast, or in skin folds.
4. Skin Rash
A maculopapular rash may appear around 5–7 days after the onset of fever. It usually spreads across the trunk and limbs but is often not itchy. The rash may fade on its own or develop into more severe skin lesions in advanced cases.
5. Lymph Node Swelling (Lymphadenopathy)
Swelling of the lymph nodes near the infection site is common. The nodes may feel tender and firm upon examination.
6. Gastrointestinal Symptoms
Nausea, vomiting, diarrhea, and abdominal pain may accompany the fever. In some patients, these symptoms are so severe that they are misdiagnosed as other gastrointestinal diseases.
7. Cough and Breathing Issues
As the infection progresses, some patients may develop dry cough, chest pain, or breathlessness, especially if the lungs are affected (pneumonitis or pulmonary edema). This is more common in severe cases.
8. Confusion or Drowsiness
When the central nervous system is involved, patients may experience confusion, irritability, or altered mental status. This is a warning sign of encephalitis—a serious neurological complication of scrub typhus.
9. Fatigue and Weakness
Extreme tiredness and lethargy often persist even after the fever subsides. Many patients feel weak for days or even weeks after recovery, especially if the illness was prolonged.
Mild vs Severe Symptoms
While many patients experience mild to moderate symptoms, about 20–30% of untreated cases can become severe. Complications include:
Acute respiratory distress syndrome (ARDS)
Liver and kidney dysfunction
Heart inflammation (myocarditis)
Brain inflammation (meningoencephalitis)
Prompt diagnosis and antibiotic treatment are crucial to avoid these outcomes.
Who is at Risk?
People at the highest risk include:
Farmers and agricultural workers
People working in forests, hills, or grasslands
Children playing outdoors in rural areas
Campers, hikers, and military personnel
The disease is not contagious person-to-person, but people in close proximity to mite-infested areas are at high risk of infection.
Diagnosis of Scrub Typhus
Diagnosis can be challenging due to its resemblance to other febrile illnesses like dengue, malaria, and typhoid. However, specific tests can confirm scrub typhus:
IgM ELISA test – commonly used to detect antibodies
PCR testing – identifies the bacterial DNA
Weil-Felix test – an older, less specific test still used in some regions
Observation of eschar – highly diagnostic if present
Doctors often start treatment based on clinical suspicion, especially in endemic areas, before test results are available.
Treatment for Scrub Typhus
Treatment is straightforward and highly effective if started early. The antibiotic of choice is Doxycycline, which is usually given for 7 to 10 days. Alternatives include:
Azithromycin – preferred in pregnant women and children
Chloramphenicol – used in select cases
Most patients begin to show significant improvement within 48 hours of starting antibiotics. Delayed treatment increases the risk of severe complications and mortality.
Preventing Scrub Typhus
Since there’s no vaccine yet, prevention revolves around avoiding contact with infected mites. Here are some tips:
Wear long-sleeved clothing and full-length pants in vegetation-heavy areas
Apply insect repellent containing DEET on exposed skin
Avoid sitting or lying directly on the ground
Use permethrin-treated clothing when hiking or camping
Shower and scrub the skin after outdoor exposure
Avoiding known mite habitats during high-risk seasons (monsoon/post-monsoon) is also helpful.
Conclusion
Scrub typhus may be an unfamiliar name to many, but it is a serious and potentially life-threatening disease in India and other Asian countries. Recognizing the early signs and symptoms can make all the difference.
To summarize, what are the symptoms of scrub typhus? Look out for sudden high fever, intense headache, rash, body pain, and the presence of an eschar. Fatigue, vomiting, and confusion are additional signs that the disease is progressing and medical attention is urgently needed.
With timely diagnosis and proper antibiotics, scrub typhus is completely curable. Awareness, prevention, and early treatment can prevent complications and save lives.