ATLANTA (AP) — Health officials say 118 cases of measles have been reported in the United States so far this year — the highest number this early in the year since 1996.

The Centers for Disease Control and Prevention on Tuesday released the count for January 1 through May 20. Cases were seen in 23 states. None of the patients died, but about 40 percent were hospitalized.

The U.S. normally sees about 50 cases of measles in a year, thanks to vaccinations. About 90 percent of the cases this year were unvaccinated.

Measles is highly contagious and up to 90 percent of people exposed to an infected person get sick. The virus spreads easily through the air, and in closed rooms, infected droplets can linger for up to two hours.

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