Background Chicken pox is a highly contagious airborne infection, caused by Varicella zoster virus, capable of causing nosocomial outbreaks, particularly in healthcare settings with susceptible healthcare workers (HCWs). Data on structured outbreak investigation in Indian hospitals remains limited. 

Methods An outbreak investigation was conducted in the Department of Internal Medicine, All India Institute of Medical Sciences (AIIMS) Rishikesh, a tertiary care teaching hospital, from 02 November 2025 to 19 January 2026, following the identification of a clinically diagnosed varicella case. A multidisciplinary outbreak response team, comprising an Infectious Disease Physician, an Intensive Care Unit physician, an Infection control nurse, a senior and junior resident, and senior nursing officers, implemented active case finding, contact tracing, immunity assessment, isolation, and post-exposure prophylaxis (PEP). Cases were identified based on clinical criteria. 

Results Institution-wide notification was made with enhanced surveillance. A total of eight cases were investigated, including one index case, two primary cases, and five secondary cases. A total of 110 healthcare workers (HCWs) were assessed. Primary and secondary attack rates were 40% and 50%, respectively, with no tertiary transmission. One HCW (14.2%) had prior history of chickenpox. All cases were isolated and treated promptly. One HCW developed post-herpetic neuralgia; the rest recovered without complications. 

Conclusion Early identification, systematic contact tracing, isolation, and targeted PEP effectively contained this outbreak. This experience highlights the need for structured standard operating protocols – ‘V-OUTBREAK SOP’ model (can be used by other hospitals) and HCW training in transmission-based precautions in Indian hospitals for effective prevention of nosocomial outbreaks.