A frightening measles outbreak in The Bronx and upper Manhattan infected 16 people, including four who needed hospitalization, according to the city Health Department.

The victims, including nine kids, were diagnosed with the contagious infection in Inwood, Washington Heights, High Bridge, Morrisania and the Central Bronx, officials said.

Authorities are urging parents to vaccinate their children and to immediately seek medical attention if they any symptoms are identified.

Shaken Bronx residents said they were on high alert for the nasty affliction — including one woman who had the measles as a child.

“It felt like a fever, you got very itchy, and all of these little bumps were all over your body,” said Naty Levcel of Parkchester. “It was a lot of pain. It lasted like a month or two.”

Officials said the infected adults ranged in age between 22 and 63 and that investigators were trying to pinpoint where the outbreak started.

While the measles normally subsides on its own, officials said some victims suffer serious complications that can include pneumonia, miscarriage, brain inflammation and even death.

The last major measles outbreak occurred last year in Brooklyn, where 58 cases were diagnosed between March and June in Williamsburg and Borough Park.