# Measles Outbreak Driven by Nosocomial Transmission, Armenia, February–July 2023

## TL;DR

A measles outbreak in Armenia was largely caused by transmission in healthcare settings, highlighting the need for better vaccination practices.

## Contribution

The study identifies nosocomial transmission as a key driver of the outbreak and emphasizes vaccination for healthcare workers.

## Key findings

- 75% of measles cases were unvaccinated individuals, with 70% exposed in healthcare facilities.
- Most affected were children under 5 years of age.
- The outbreak involved three transmission chains with 183 cases.

## Abstract

During March–July 2023, we investigated a measles outbreak in Armenia. Of 287 patients, 130 were <5 years of age and 215 (75%) were unvaccinated. Among 3 transmission chains involving 183 cases, 70% of patients were exposed in healthcare facilities. To minimize nosocomial transmission, measles vaccination should be encouraged among healthcare workers.