The rash of measles breaking out across the country is spreading into Pennsylvania.

The disease was believed to have been eradicated in the United States in 2000, thanks to routine vaccinations. But it has begun to crop up again after parents became wary that the inoculations may hurt their children and refused to have them vaccinated.The Pennsylvania Department of Health reported a case in Cumberland County. It immediately set up a clinic where 300 people received vaccinations, which health authorities believe contained the virus, said Harrisburg infectious disease specialist John Goldman.Another case has been reported in an unvaccinated 1-year-old baby in New Jersey. Children typically get the first of two doses of measles inoculations when they are 12 to 15 months old and the second between 4 and 6 years.The U.S. Centers for Disease Control and Prevention counted just 63 cases in 2010. But the number jumped to 220 in 2011, and to 644 last year. So far this year, there have been 102 cases, most of them stemming from an outbreak in December at Disneyland, in Anaheim, California.The one in Pennsylvania was not related to the Disneyland outbreak.In Pennsylvania, there were two cases in 2010, 13 in 2011, two in 2012, none in 2013, three in 2014, and one so far this year, said state Department of Health spokeswoman Holli Senior.Measles is extremely contagious. The virus stays in the air for hours."You can get measles just by walking by a room where someone is who has measles," Goldman said.VaccinationsBefore 1963, when the measles vaccine was licensed, CDC estimates there were between 3 million and 4 million cases a year, with about 500 deaths annually.After the vaccine became available, the incidence dropped by 98 percent. By 1983, a record low of 1,497 cases were reported.But the disease broke out again from 1989 through 1991, with a total of 55,622 cases, and 123 deaths, reported. The resurgence was due to low vaccination rates among minorities, according to the CDC.Increased education efforts again drove down the rates, which hit a low of 37 in 2004.Health authorities say most cases of measles in the United States are brought in by people from foreign countries. That's where they believe the Disneyland outbreak originated.The disease then spreads among those who have not been vaccinated."That outbreak was completely preventable," Goldman said.Pennsylvania requires immunizations for all school-age children, even those who are home-schooled. But only about 87 percent of kindergarten age children were vaccinated in 2013-2014, among the lowest rates in the nation, said Dr. Rachel Levine, Acting Pennsylvania Physician General.But among seventh-graders, the percentage jumps to 95.98, among the highest, she said. Health authorities had no explanation for the disparity.A 95 percent rate is necessary for what Goldman called "herd immunity," the level needed to prevent outbreaks."If you've had two doses of the vaccine, you are protected," Levine said.ResurgenceHowever, measles outbreaks are again increasing. This time, health authorities believe the increase may be due to complacency, and to a small but growing number of parents who are convinced the vaccinations are harmful.Much of the anti-vaccine movement is grounded in a since-discredited study by a British doctor, Andrew Wakefield, who in 1998 claimed to have established a link between the measles-mumps-rubella vaccine and autism. His study, of 12 children, was discovered to be fraudulent and denounced by medical authorities, and Wakefield's medical license was revoked.But the fears continue. Recently, politicians have jumped into the fray.Sen. Rand Paul, R-Kentucky, said in a recent interview with CNBC that parents should be given more choice about vaccines.His pronouncement followed Republican New Jersey Gov. Chris Christie's similar statement. Christie's spokesman Kevin Roberts a few days later walked back the statement, saying children need to be vaccinated against measles.