NEW YORK (CBS) Measles cases are approaching numbers the United States hasn't seen in 20 years. More than 70 new cases are being reported, most of them from two large outbreaks in New York.
Pediatrician Dr. Jeffrey Avner is on the front lines of a measles outbreak that is showing no signs of slowing down..
"When you see a disease that is preventable with vaccination it is somewhat disheartening," said Avner, the chair of pediatrics at Maimonides Children's Hospital of Brooklyn.
His hospital has treated nine cases of measles so far, including an adult and a child who ended up in the intensive care unit.
"Parents don't really understand risks of measles because they haven't seen measles because it's become such a rare disease, but measles does have very serious complications. One in 20 children with measles get pneumonia, which by the way is the most common cause of death," Avner said.
The Centers for Disease Control and Prevention is now reporting 626 cases of the highly contagious virus in 22 states, the second highest number of cases reported since measles was declared eliminated in 2000.
Most of the New York cases have occurred in unvaccinated people in Orthodox Jewish communities. Doctors across the country are also fighting against an anti-vaccine movement among some parents.
"They are getting information from sources that are incorrect, that are trying to sell them on ideas and studies that were fraudulent and debunked," Avner said.
He says if people stay unvaccinated, the measles could continue to spread.
Some experts are concerned with Passover this week, there will be an increase in measles cases after the holiday in the coming weeks.