Scrub Typhus in Northern India: An Overview of Epidemiology, Risk Factors, Seasonal Patterns, and Public Health Implications.

Scrub typhus, caused by Orientia tsutsugamushi and transmitted by larval trombiculid mites, has become a major re-emerging infectious disease across Northern India, especially in the sub-Himalayan region. This review highlights current evidence on its epidemiology, regional variations, risk factors, and seasonal trends using surveillance, hospital-based, and outbreak data. The North Indian states of Himachal Pradesh and Uttarakhand, along with adjoining regions of Uttar Pradesh, report many cases in hospital settings and outbreaks in the community, with a seasonal peak from July to November coinciding with climatic conditions that likely favour vector proliferation. The transmission of scrub typhus is closely associated with occupational exposure in agriculture and forestry, proximity to scrub vegetation and rodents, and behavioural practices that increase contact with mites. The clinical presentation often overlaps with other febrile illnesses, complicating the diagnosis, and due to limited diagnostic infrastructure, scrub typhus is likely underreported, particularly in districts with low diagnostic capacity, resulting in delayed treatment. The public health implications include recurrent monsoon-related outbreaks, a heavy healthcare burden, risks of antimicrobial misuse, and antimicrobial stewardship concerns, especially when the diagnosis is uncertain. This review highlights the need for integrated control strategies, such as district-level diagnostics and surveillance integration, along with personal protection, environmental management, improved diagnostics, community awareness, sustained surveillance, and research on vector ecology, strain diversity, and vaccine development. Strengthening multi-sectoral collaboration holds the greatest potential to reduce the growing burden and mortality from scrub typhus in Northern India.