Scrub Typhus: Epidemiology, Clinical Presentations, and Diagnostic Approaches

Abstract

Scrub typhus (ST) is one of the most neglected tropical diseases, a leading cause of acute undifferentiated febrile illness in areas of the ‘tsutsugamushi triangle’, diagnosed frequently in South Asian countries. The bacteria Orientia tsutsugamushi is the causative agent of the disease, which enters to human body through the bite of trombiculid mite (Chigger) of the genus Leptotrombidium deliense.The diagnosis of the disease becomes challenging as its early symptoms mimic other febrile illnesses like dengue, influenza, and corona viruses. Lack of rapid, reliable, and cost-effective diagnostic methods further complicates the identification process. Northeast India, a mountainous region with a predominantly rural tribal population, has witnessed a resurgence of scrub typhus cases in recent years. Various ecological factors, including rodent population, habitat characteristics, and climatic conditions, influence its prevalence. Entomological investigations have confirmed the abundance of vector mites, highlighting the importance of understanding their distribution and the probability of transmission of scrub typhus in the region. Proper diagnosis, awareness campaigns, and behavioral interventions are essential for controlling scrub typhus outbreaks and reducing its impact on public health in Northeast India. Further research and community-based studies are necessary to accurately assess the disease burden and implement effective prevention strategies.

Unravelling the Enigma of Scrub Typhus: A Critical Review and Insights Into Epidemiology, Clinical Features, Diagnostic Advances, and Emerging Trends

“…Narang et al found scrub typhus affecting 15.89% of the population in 2023, with a higher prevalence among individuals aged 41-60, females, and farm workers, particularly during monsoon and post-monsoon seasons[22]. Pandey et al highlighted a significant number of cases in Eastern India, especially Nagaland and Manipur[23]. Devamani et al conducted a study in south India, in the Tamil Nadu districts of Vellore, Thiruvannamalai, and Salem, and recruited 1,353 individuals from 15 peri-forest hill villages, 17 rural plain villages, and 16 urban communities.…”

“…Narang et al observed 15.80% prevalence, with higher rates in the 41-60 year age group, in females, and among farm workers during monsoon seasons[22]. In the study in Northeast India byPandey et al, 55.5% of cases were primarily from Nagaland and Manipur, with a 2.4% case fatality rate[23]. Damodar et al linked scrub typhus to AES in south Indian states[25].…”