The death of a 20-year-old Anna University student from scrub typhus has brought attention to an infection that can begin with what appears to be an ordinary fever but, in some patients, can progress rapidly and impact several organs.The student, who was staying in a campus hostel, developed high fever and was admitted to a government hospital after about four days of illness. He was subsequently referred to Government Kilpauk Medical College Hospital, where doctors reported that he arrived with altered sensorium, characterised by disorientation, confusion, incoherent speech and drowsiness. He tested negative for dengue but positive for scrub typhus. According to the hospital, complications included respiratory distress and multi-organ failure, and he died soon afterwards.The case is particularly important because scrub typhus is one of several infections that can initially present simply as acute fever. Its symptoms can overlap with dengue, malaria, leptospirosis and other infections that are common or seasonally prominent in India. So the bigger question is how easily can scrub typhus be missed, and what should a timely assessment look like? “Scrub typhus is treatable if diagnosed early but complications can become serious. A doctor assessing someone with unexplained fever may need to consider questions such as have the symptoms deteriorated, is the patient getting better or deteriorating? Have they spent time around grass, bushes or other vegetation? Is scrub typhus circulating in the area? Are there laboratory abnormalities or developing symptoms suggesting involvement of other organs? The diagnosis is not based on one symptom alone,” Dr Jatin Ahuja, Consultant, Infectious Disease, Indraprastha Apollo Hospital, Delhi told The Indian Express.What is scrub typhus?Scrub typhus can occur in rural and peri-urban environments where mite habitats exist. It is a bacterial infection caused by Orientia tsutsugamushi. It is transmitted to people through the bite of infected larval mites, commonly known as chiggers. These mites are associated with particular environments, including areas with scrub vegetation, grass, bushes and other ground cover. Scrub typhus occurs across parts of Asia, including India.The infection can range from a febrile illness to severe disease affecting multiple organs.Also Read | Amid a steady rise in scrub typhus cases in India, know 10 things about the diseaseThe National Centre for Disease Control (NCDC) notes that serious manifestations can include acute respiratory distress syndrome, meningo-encephalitis, shock and kidney failure.What are symptoms?Fever is usually the dominant symptom. Patients may also have headache, chills, muscle or body aches, weakness and sometimes a rash or swollen lymph nodes. A particularly useful clue can be an eschar — a dark, scab-like lesion at the site of the mite bite. But not every patient develops it. That means the absence of a characteristic skin lesion cannot safely be used to rule out scrub typhus. This is where history-taking of the patient’s history becomes important.Why dengue can complicate the pictureIn India, a patient with fever and low platelet counts may immediately raise concern about dengue. ICMR (Indian Council of Medical Research) guidance notes that scrub typhus can clinically mimic dengue, leptospirosis and malaria. Fever, thrombocytopenia and abnormalities involving the liver can occur in several of these infections. This means that a negative test for one infection does not automatically identify the cause of the fever.Story continues below this adWhat about diagnosis and treatment?ICMR identifies IgM ELISA as a mainstay of laboratory diagnosis. NCDC has also described the use of ELISA and molecular testing such as PCR in its diagnostic approach.Treatment should not necessarily wait for laboratory confirmation. ICMR says that if mite disease is suspected, then antibiotic therapy should be started. It specifically recommends initiating doxycycline in suspected cases with complications before referral to a higher-level facility.Also Read | Understanding scrub typhus, the jungle fever that is stalking Himachal PradeshThis does not mean every fever should automatically be treated for scrub typhus. It means that where the clinical picture is compatible and suspicion is sufficiently high, the possibility of waiting too long for confirmation has to be weighed against the risk of progression.When does scrub typhus become dangerous?ICMR guidance specifically identifies Acute Respiratory Distress Syndrome (ARDS), acute renal failure, meningo-encephalitis and multi-organ dysfunction as complications warranting referral to a secondary or tertiary centre. For that reason, a patient with fever who develops breathing difficulty, confusion or altered consciousness, falling blood pressure, reduced urine output, severe weakness or other evidence of organ dysfunction needs urgent reassessment and escalation of care.Who should doctors think about when considering scrub typhus?Anyone living in or travelling through an area where scrub typhus occurs can potentially become infected. People who spend time around vegetation, grass, bushes or other mite habitats may have greater exposure, including agricultural workers, gardeners, forestry workers and people undertaking outdoor activities.