An outbreak of measles linked to two Disney theme parks in California
has put the spotlight back on an infectious disease that was considered
eradicated in the United States a decade ago.
More than 120 people in 17 states have contracted the
measles following the initial exposure by 42 people to the
infection at the theme parks in December, according to the Centers for Disease
Control and Prevention.
This isn’t the first outbreak of this kind. Last year, the CDC
reported a record number of cases, with 644 measles cases reported in 27
states, the largest number since the disease was declared eliminated in the
United States in 2000.
Measles can occur up to three weeks after the initial exposure. However,
secondary exposures continue to be reported from people who came in contact
with those who first contracted the infection at Disneyland.
Measles is a highly infectious, airborne disease that typically begins with fever, cough, runny
nose and pink eye, and within a few days a red rash appears, usually first on
the face and then spreading downward to the rest of the body.
Infected people are contagious for about four days
before their rash appears to about four days after. It is so contagious that if
one person has it, 90 percent of the people that person comes in contact with
will also become infected.
While the CDC calls measles “unpleasant,” the agency
warns that complications from the disease can be dangerous. Six to 20 percent
of people who contract measles can also develop an ear infection, diarrhea and
pneumonia. In serious cases, one
out of 1,000 people with measles will develop inflammation of the brain
(encephalitis or meningitis), and about one out of 1,000 will die.
After the widespread introduction of a vaccination program in the 1960s,
measles cases had virtually disappeared in the United States. The CDC reports a greater than 99 percent reduction in cases compared to the era prior to
However, measles is still common in other countries. Approximately 20 million people get measles each year, and 122,000 die from the disease.
Although measles cases in the U.S. showed a spike in 2014 and the number of cases continues to increase this year, it’s
still too soon to say the disease is making a comeback, according to Dr.
Charles Bregier of Novant Health Urgent Care and Occupational Medicine.
Because this disease is so infectious, it’s important to get vaccinated.
Measles is thought to be the most infectious disease known, as the virus can
remain suspended in the air in a room for up to an hour after an infected
person who coughed or sneezed has left the room. The measles vaccine, MMR,
protects against measles, mumps and rubella and has been in use since 1968.
Public health officials say children should get two doses of the MMR
vaccine, starting with the first dose between 12-15 months of age, followed by
a second dose between age 4- 6.
According to the CDC, adults don’t need the vaccine if:
- Blood tests show you are immune to measles, mumps and rubella.
- You were born before 1957.
- You already had two doses of MMR or one dose of MMR plus a second dose of measles vaccine.
However, the CDC recommends that all college students, people who work
in a medical facility, international travelers and women likely to become
pregnant get vaccinated.
Why we’re seeing an uptick in measles:
While vaccination used to be virtually universal in this country, vaccine
rates have been declining since the 1990s. National
statistics show children’s vaccination rates falling below 90 percent in 17
states. In some communities, there are
clusters of families with unvaccinated children making them more vulnerable to
Adults can be vulnerable, too. In the Disneyland outbreak, 13 of the
confirmed cases were in adults. The CDC said that these adults who contracted measles were not vaccinated.
“Although the immunity rate is so high, the immunization isn’t perfect,”
Bregier said. “Even if there is a 99 percent immunity rate from the vaccine,
there’s a 1 percent chance someone could contract measles.”
Still, Bregier thinks we’re much better off today than before vaccination
was the norm. Before the immunization program, 3 million to 4 million Americans
contracted measles each year, including 400-500 deaths and 48,000
hospitalizations, according to the CDC.
Bregier also mentioned that until1989, children
only received one measles vaccine instead of two, so there’s a chance that
adults contracting measles today only had one vaccine and aren’t as well protected.
He added that immunology and public health research is ongoing, and the CDC or
World Health Organization (WHO) may recommend an additional MMR vaccine if they
feel the risk of measles is increasing.
“When you think about how things change, such as pertussis and the
now-recommended Tdap (tetanus, diphtheria and pertussis) booster after age 9,
you realize the CDC and WHO are keeping an eye out for immunization
recommendations that need updating,” Bregier said. “If they think the risk of
measles is increasing, they may recommend an additional booster. I wouldn’t be
surprised if they eventually make changes, but it’s also too soon to tell.”
If you aren’t sure if you are current with your MMR vaccination, consult
with your physician.