NEW YORK — U.S. health officials on Thursday reported 971 measles cases so far this year, the highest tally in 27 years, and experts say it’s not clear when the wave of illnesses will stop.
Measles, once common in the U.S., became rare after vaccination campaigns that started in the 1960s. A decade ago, there were fewer than 100 cases a year.
The new numbers from the Centers for Disease Control and Prevention pushed the U.S. tally higher than the 963 illnesses reported for all of 1994. The nation last saw this many cases in 1992, when more than 2,200 were reported.
Overall, vaccination rates have remained fairly high, but outbreaks have been happening in communities where parents have refused recommended shots, U.S. health officials say.
“What’s causing these outbreaks is lack of vaccination,” said Dr. Mark Roberts, chair of health policy and management at the University of Pittsburgh Graduate School of Public Health.
Illnesses have been reported in 26 states, but the vast majority are in New York City.
The city’s outbreak, which began last October, is already the largest local measles outbreak in the U.S. in nearly 30 years. It started when some unvaccinated children visited Israel, where a measles outbreak is occurring, and came back to New York.
More than 500 cases have been diagnosed in two Brooklyn neighborhoods — Williamsburg and Borough Park — and mainly among unvaccinated children in Orthodox Jewish communities. Forty-two have been hospitalized, including 12 treated in intensive care units.
More than 25,000 doses of vaccine have been given to children and teenagers in those two neighborhoods since October.
Some have been motivated by a city order issued in April that all children and adults who live in four Brooklyn ZIP codes be vaccinated or face fines up to $1,000. City officials say 123 people have received summonses for not complying with the order.
The city health department has put 400 people to work on the outbreak, and forged new relationships with community organizations to make a better case for vaccinations.
The officials say it’s all paying off. New measles diagnoses dropped from 173 last month to 60 this month.
“I’m confident that the work that we have put in place … put us on the right trajectory to bring this outbreak to an end soon,” said Dr. Oxiris Barbot, New York City’s health commissioner.
Some health experts see this outbreak as a sign that other vaccine-preventable illnesses could worsen.
“Measles is incredibly contagious,” CDC Director Dr. Robert Redfield said in a statement. “We need to act together now to stop this outbreak before there are even more serious consequences.”
In most people, measles causes fever, runny nose, cough and a rash all over the body. However, a very small fraction of those infected can suffer complications such as pneumonia and a dangerous swelling of the brain.