Measles has infected 84 people in 14 states this year

A resort such as Disneyland, where visitors mix with people from all over the world before flying home, is the perfect place to start a nationwide measles epidemic, public health experts say.

Yet a Disneyland measles outbreak that has spread to eight states and Mexico could also help turn around a trend in which more parents have opted out of vaccinating their children.

A growing number of parents in recent years have skipped their children's vaccines because of a discredited belief that vaccines are linked to autism. That has led to pockets of unvaccinated children, says Mark Schleiss, a pediatric infectious disease physician at the University of Minnesota.

"We could be on the threshold of a watershed event, where we see large outbreaks in many cities," Schleiss says. "But perhaps this will also be watershed event to refocus attention on the safety of vaccines."

According to the Centers for Disease Control and Prevention, 84 people in 14 states were diagnosed with measles from Jan. 1 through 28. Most were infected either at Disneyland or by someone who went there.

That means the USA had more cases of measles in January than it usually has in an entire year, says Anne Schuchat, assistant surgeon general. About 15% of measles patients have been hospitalized.

Most of the infected people had not been fully vaccinated, she says.

"This is a wake-up call to make sure that we keep measles from regaining a foothold in our country," Schuchat says.

Last year was a particularly bad year for measles, driven both by huge outbreaks in Asia as well as rising rates of unvaccinated children. Doctors diagnosed 644 people with the virus, according to the CDC. Although health officials don't know who started the Disneyland outbreak, they have said it was probably a foreign visitor.

Measles infects 20 million people around the world each year, killing 145,000, Schuchat says.

Yet the disease didn't get much attention until it arrived at Disneyland, says Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia, who says he has been doing non-stop news interviews about measles this week.

"You really feel much more anger with this outbreak," Offit says. "What is the difference? I really think it's Disneyland."

Offit says some people are frustrated that parents who chose not to vaccinate are ruining their vacations or just ruining the idea of a happy, carefree place that's normally untouched by reality. California health officials have warned unvaccinated people not to go to Disneyland and not to take babies too young to have had their first shots.

California schools have sent dozens of unvaccinated students home from school to protect them and stop the spread of measles. That may educate people about how dangerous and disruptive measles can be, Offit says.

"People for years have desperately tried to make sure that parents understand what is at stake when you don't vaccinate," Offit says. "Unfortunately, the only thing that really educates people is fear of the disease."

Some examples of the disruption: Arizona has diagnosed only seven cases of measles, but those infected people have exposed as many as 1,000 others, including babies too young to have had their first measles shot, according to the Arizona Department of Health Services. Doctors recommend that unvaccinated people exposed to measles be quarantined for three weeks, the measles incubation period.

The CDC recommends that children receive a first measles shot around age 1 and a second at ages 4 to 6 before beginning kindergarten.

The Arizona measles cases began with one unvaccinated family of four from Pinal County that went to Disneyland, according to state health officials. Back at home, one of the children went to two urgent-care centers for medical attention, exposing 18 children, 13 of whom were unvaccinated. That family also exposed a woman from Maricopa County, who then exposed as many as 195 children at a child care center. A man who caught measles from the family then exposed others.

Although the routine spread of measles was eliminated in the USA in 2000, a low rate of vaccination in some communities has allowed the virus — one of the most contagious — to make a comeback, says Walter Orenstein, a professor and associate director of the Emory Vaccine Center in Atlanta. Measles vaccination rates range from a low of 81% of kindergarten students in Colorado to a high of nearly 100% in Mississippi.

The current generation of parents has no experience with measles, Orenstein points out. A growing number have skipped or delayed children's vaccines because of debunked myths about vaccines causing autism, Orenstein says.

"People don't see these diseases, they don't fear these diseases, and they don't know how serious these diseases can be," he says.

Measles is a tenacious virus that lingers in the air and can infect people two hours after a sick person has left the room. People with measles are contagious even in the early days of the infection, when they have symptoms similar to those of a cold and the telltale red rash has not appeared, Orenstein says. On average, one measles patient can infect as many as 18 susceptible people — those who are unvaccinated and who have never had measles.

For every 1,000 cases of measles, two to three people die, Orenstein says. Children can develop pneumonia, deafness or encephalitis, an inflammation of the lining of the brain.

During a measles outbreak from 1989 to 1991, more than 55,000 Americans were infected, more than 11,000 were hospitalized and 166 died, according to the CDC.

Children with measles are miserable even if they don't develop serious complications, Offit says. The disease can last up to two weeks, causing fevers of 103 to 105 degrees, ear infections, diarrhea and loss of appetite that can lead to dehydration. Children can become so sensitive to light that they need to lie in bed in a darkened room.

One way doctors diagnose measles, Offit say, is by noting a child's degree of misery. "Children with measles are inconsolable," he says.

Controlling a measles outbreak is expensive and time-consuming. Each case in a measles outbreak in 2008 cost taxpayers more than $10,000 as public health staff traced each patient's contacts, quarantined patients and administered vaccines.

Offit says he's seen a big change in news coverage of the Disneyland measles outbreak. Ten or 15 years ago, he says, reporters often gave credence to parents claiming that vaccines caused their children to develop autism. Since then, studies have debunked any link between autism and childhood immunizations — a fact Offit sees reflected in coverage now.

The Disneyland outbreak "gives us a chance to have important conversations about what vaccines do and what they protect us from," says Claire McCarthy, a pediatrician at Boston Children's Hospital. "These other measles outbreaks haven't seemed quite real to people. Disneyland has made it real."

About 25% of measles patients have been sick enough to be hospitalized, according to California health officials. McCarthy says she fears many more will be hospitalized before the outbreak is under control.

"This has the potential to get really huge," McCarthy says. "We don't know how big this will get."

Pediatrician Bob Sears, author of TheVaccine Book, says he thinks more families will vaccinate against measles as a result of the outbreak. But he doubts skeptical parents will be more likely to follow the CDC schedule for other vaccinations.

"Because measles has been so rare in the past 20 years, parents had the luxury to forgo the vaccine without risking disease," Sears says. "When an outbreak occurs, that sense of security goes away."

Although Sears recommends that parents vaccinate children against measles at age 1, the same age recommended by the CDC, he has popularized an alternative vaccine schedule that stretches out the length of time between shots because some parents worry about too many shots at once. Critics say that leaves children vulnerable to dangerous diseases for an unnecessarily long time.

"Parent should have the freedom to consider the pros and cons of the (measles) vaccine and make an educated decision for their child," Sears says.

Schleiss points out that parents who choose not to vaccinate may find themselves taking three weeks off work or hiring a babysitter when their unvaccinated children are excluded from class.

"That comes with the territory when you choose not to vaccinate," he says.