Measles

Active outbreak in Rockland County. 12 confirmed cases as of June 6, 2026. All cases in unvaccinated individuals. NYSDOH contact tracing ongoing.

What is it?

Measles is caused by the measles virus (morbillivirus) and is one of the most contagious infectious diseases known — one infected person can infect 12–18 others in an unvaccinated population. NYS had 15 cases in 2024, with outbreaks linked to communities with low vaccination rates. Before the vaccine era, virtually every child got measles; today, any case signals inadequate vaccination coverage.

How it spreads

Airborne transmission — the virus spreads through respiratory droplets and can remain in the air for up to 2 hours after an infected person has left a room. A person is contagious from 4 days before the rash appears through 4 days after it appears.

Symptoms

High fever, cough, runny nose, and red, watery eyes (conjunctivitis) for several days, followed by Koplik's spots (small white dots inside the mouth) and then a red, blotchy rash that starts at the hairline and spreads downward. Complications include ear infections, pneumonia, encephalitis, and rarely death — more common in malnourished children and immunocompromised individuals.

Who is at risk?

Unvaccinated individuals of any age. Infants too young to be vaccinated depend entirely on community immunity. International travelers to endemic areas. People born before 1957 are generally considered immune through natural infection.

What you can do

Vaccine information

Two doses of MMR vaccine are 97% effective against measles. First dose at 12–15 months, second dose at 4–6 years. Infants 6–11 months traveling internationally may receive an early dose (does not count toward the 2-dose series).

Any confirmed case in a county triggers an elevated alert. Updated manually when NYSDOH issues outbreak notifications.