Incidence of Scrub Typhus in a Tertiary Care Hospital in Kolkata, India: A Cross-sectional Study Approach

Background: Scrub typhus is an endemic disease in India caused by Orientia tsutsugamushi, transmitted by trombiculid mites. It is an important cause of acute febrile illness in India. Signs and symptoms include fever, headache, myalgia and GI symptoms and is generally associated with morbilliform rash (<40%), eschar (<50%) which is due to bite of the mite. Abnormal LFTs and lymphocytosis are commonly seen in early phase of illness. It’s often labelled as PUO. Early diagnosis and prompt administration of therapy mostly leads to complete recovery.

Aims: The present study aimed to highlights the incidence of scrub typhus in a tertiary care hospital in Kolkata, India.

Methods: Authors screened 100 patients presenting with fever, malaise, headache, with or without rash for more than a week from the month of May to December 2019. Routine blood investigations with fever profile (Dengue NS1 antigen, MP, MPDA, TyphidotM) and cultures were done. Patients in whom no cause of fever could be established, having lymphocytosis, hyponatremia and transaminitis, they were tested for Scrub typhus by using Indirect immunofluorescence & detection of IgM antibody.

Results: Total 22 patients were found positive for scrub typhus by using the aforementioned method (22%). Male: Female ratio was 3:4 (9 vs 12). Patients were in the age group of 16-76 years. Lymphocytosis, hyponatremia and transaminitis were cardinal features seen in almost all patients diagnosed with Scrub Typhus.

Conclusions: This study will help clinicians to have a stronger suspicion of scrub typhus in undiagnosed febrile patients. Clinically, younger patient population, rapid diagnosis, and prompt treatment may be associated with a shortened disease course and a better outcome.