Disneyland measles outbreak continues to spread

A measles outbreak that started at Disneyland in California is spreading further across the country and into Mexico as people who were infected on their vacations take the virus home to unvaccinated family members.

More than four dozen people in four states have been diagnosed with measles related to Disneyland or the adjacent Disney California Adventure Park in Orange County.

As the first measles patients create new clusters of disease, "I think we'll see some satellite outbreaks," says William Schaffner, an infectious disease expert and professor at the Vanderbilt School of Medicine in Nashville. "It's going to take a while to control."

The first group of patients to develop measles had visited the parks from Dec. 15 to Dec. 20, according to California health officials. The officials have not yet identified "patient zero," the person who started the outbreak. People can develop measles three to 21 days after being exposed.

At least 42 cases of measles related to Disney have been diagnosed in California, plus three in Utah, two in Washington, one in Colorado and one in Mexico. The Mexican case is a 22-month-old girl.

Robert Glatter, an emergency physician at New York's Lenox Hill Hospital, says the Disney outbreak "has the potential to be develop into one of the worst outbreaks since 1989."

From 1989 to 1991, U.S. doctors diagnosed more than 55,000 measles cases with 166 deaths, according to the Centers for Disease Control and Prevention. In response, Congress funded the Vaccines for Children Program, providing free shots to low-income kids for all recommended vaccinations.

Measles was declared eradicated in the USA in 2000, meaning that it no longer spreads routinely like the common cold. The country continued to experience a few dozen cases a year as travelers from abroad were diagnosed here.

Last year, though, measles infected 628 people, according to the CDC.

The recent surge in measles cases reflects the impact of huge measles epidemics around the world. In 2014, there were more than 57,000 cases in the Philippines and more than 17,000 in Vietnam, according to the World Health Organization.

The increased rate of measles also reflects the influence of the anti-vaccine movement, Schaffner says.

Some parents are hesitant to immunize their children because of a widespread belief that vaccines cause autism. That is a myth that has been thoroughly debunked, says Peter Hotez, president of the Sabin Vaccine Institute.

The measles shot is "one of our oldest and safest vaccines, developed more than 50 years ago," Hotez says.

Vaccination rates in the USA are generally high. But measles can spread quickly among children of "vaccine-resistant" parents, who sometimes cluster together, living near like-minded parents with doubts about vaccine safety, Schaffner says.

California health officials say Disney did nothing wrong.

Measles is one of the most contagious of all viruses, Hotez says. Measles can linger in the air for hours, infecting people even after a sick person has left the room.

Big theme parks are an ideal place to start the spread of measles because people who visit them may fly back to homes all over the world, spreading the virus as they go, Schaffner says.

Around the country, state health officials are urging susceptible people – those who haven't had measles or haven't been vaccinated – to get their shots.

Health officials in Orange County, Calif., where the Disney parks are, issued a letter to parents last week saying that unvaccinated children exposed to measles may be excluded from school or day care for up to 21 days. "That's a pretty significant incentive to make sure your child gets immunized," says Eric Handler, public health officer for Orange County, Calif.

Most of those who have contracted measles were unvaccinated, Handler says.

The CDC recommends children get a first measles shot at age 12 to 15 months, then a second shot at 4 to 6 before entering school. Two doses of measles vaccine are 99% effective at preventing the disease.

To prevent future outbreaks, states should consider strengthening laws that require children to receive recommended vaccines before beginning school, Schaffner says.

All states require vaccination before beginning public school, but 48 states grant religious exemptions and 19 states allow kids to skip vaccines for philosophical reasons, according to the National Conference of State Legislatures.

One in 20 children with measles develop pneumonia, the most common cause of death from measles, according to the CDC. For every 1,000 children with measles, one or two will die.

California health officials are urging people with suspected measles cases to call their doctors first, rather than show up at a clinic or emergency room, to avoid exposing others.

According to the Los Angeles Times, an urgent-care clinic near San Diego was forced to shut down last week when five people arrived with a telltale rash.

Measles symptoms include fever, rash, cough, runny nose and red eyes. Someone with measles can spread the virus for several days before the rash appears as well as after the rash clears up.

There is no treatment other than to keep the patient comfortable and hydrated.

Schaffner says health officials face an uphill battle persuading vaccine-resistant parents to immunize their children.

"I don't think we're going to see a whole lot of parents suddenly running out to vaccinate their children," he says. "The first response of human beings, when they hold a belief and are challenged, is to double down. They become more fixed in their idea, more stubborn."

Wendy Sue Swanson, a Seattle pediatrician, notes that some children are at higher risk of measles than others, including those who are immune-suppressed or who are too young to be fully vaccinated.

"We can't forget that we have responsibility for our community," Swanson says. "Not only are unvaccinated children at risk for measles right now, we have to remember that they are also at risk for spreading it, too."