DALLAS, May 14, 2014 — Clinicians at Children’s Medical Center Dallas are on the lookout for possible cases of measles, and parents in North Texas are urged to take steps that will help avoid an outbreak of this highly infectious and vaccine-preventable disease.
The Centers for Disease Control (CDC) recently reported that the number of U.S. measles cases in the first four months of 2014 is at an 18-year high. According to Dr. Jeffrey S. Kahn, director of infectious disease at Children’s and professor at the University of Texas Southwestern Medical Center, the incidence of measles in North and South America is still low compared with the rest of the world, but the U.S. uptick is an early warning signal for local parents to check their children’s vaccination schedules and make sure they are current.
“Measles is one of the most easily transmitted diseases in the world, and even with relatively small numbers in the United States it’s a cause for concern, as measles can lead to serious complications, including pneumonia, bronchitis and encephalitis,” said Kahn.
Measles is a viral respiratory disease that predominantly affects children but also strikes adults. Although it was officially declared eliminated in 2000—meaning it no longer regularly passes through the U.S. population—in recent years it has re-emerged, including an outbreak last year in Tarrant and Denton counties that put local physicians and health officials on alert. Although North Texas has not experienced a community outbreak in 2014, individual cases have been identified in Collin and Dallas counties this year.
According to the CDC, the U.S. tally now stands at 168 confirmed cases in 15 states, with the largest outbreaks in California and New York. Canada also has experienced a spike in measles this year, with 320 cases in Vancouver and smaller outbreaks in other cities. Many cases in North America have been linked to international travel, particularly from the Philippines, which has been hit hard by the disease. Globally, measles is still endemic and a leading cause of childhood mortality in the developing world.
Measles has been on the rise in Europe, too, where vaccines are widely available. The World Health Organization reports that within the WHO/Europe region, measles rose from 7,073 cases in 2007 to 31,685 cases in 2013 – an increase of 348 percent.
According to Kahn, babies less than a year old—prior to their first measles, mumps and rubella (MMR) vaccination—are particularly vulnerable, along with unvaccinated children and adults, whether by choice or because they have an underlying condition such as immunodeficiency that contraindicates vaccination. Young children who have not had a second inoculation also are more susceptible to the disease. And, fully vaccinated older children and adults may not be entirely protected due to waning efficacy of earlier vaccines. Measles also is dangerous for unvaccinated pregnant women due to high risks for spontaneous abortion, premature labor and low birth weight babies.
“Even with heightened awareness in the medical community, measles can be difficult to track and diagnose as there is a long incubation period, and many physicians and nurses in the United States have never even seen a patient with measles. However, when we notice an uptick in cases, we have to be vigilant and fully prepared for the possibility that we will see measles in the emergency room,” said Kahn.
Measles is so contagious that tiny virus particles can remain live and airborne in a room for up to two hours after a person with measles walks through it. A tight enclosure such as an airplane virtually ensures that every person will be exposed to the virus if one passenger is contagious—and possibly the next planeload of passengers, too.
According to Kahn, if a child at Children’s is diagnosed with measles, the area must be evacuated, cleaned and quarantined for several hours. He said measles can spread like wildfire in non-immunized populations and create a nightmare for public health officials who must track each sick person’s movements and alert those who may have been exposed.
There is no specific medical treatment for measles other than supportive care at home, although many children who develop complications require hospitalization. Symptoms include fever, fatigue, cough, conjunctivitis, runny nose and red rash, which usually appears four to five days after the fever begins. Children with symptoms—particularly if they have recently traveled internationally—should be evaluated for measles. Parents should contact their primary care physicians if they suspect measles.
The American Academy of Pediatrics and CDC recommend a first dose of the MMR combined vaccine at 12 to 15 months and a second dose at 4 to 6 years of age. If families are planning to travel internationally, the CDC recommends that infants 6 to 11 months old get the vaccine. Texas requires evidence of two-dose MMR vaccination prior to attending a child-care facility or public or private school in Texas, although parents may opt out by filing an affidavit for exemption. Forty-eight states allow exemptions from vaccination requirements.
After decades of widespread vaccination and virtual elimination of measles, U.S. health officials worry that the number of unvaccinated children is becoming a problem, not only for the spread of measles but also pertussis and other preventable diseases. Prior to the first licensed measles vaccine in 1963, hundreds of children in the U.S. died every year from the disease and thousands were hospitalized, some with permanent impairment. Even with the best care available today, one or two children in 1,000 with measles will die from the disease. Today’s vaccines are safe and effective, with common side effects typically mild and serious reactions rare. The risk of severe complications from measles outweighs the remote risk of severe complications from the vaccine. Parents are urged to discuss any concerns with their primary care physicians and utilize reliable sources of information to make decisions.