Two separate measles outbreaks demonstrate threat of imported cases

Health officials are contacting hundreds of people to assess their risk for contracting measles after two separate outbreaks of the disease in Maryland and Pennsylvania. Both outbreaks are believed to have started with unvaccinated travelers from foreign countries.

In Montgomery County, Maryland, four patients with measles have been reported since February. The most recent patient was tested for measles this weekend at Shady Grove Hospital.

David Paulson, communication director for the Maryland Department of Health and Mental Hygiene, said at this point it is uncertain whether this patient, who at press time was presumed to have measles, is connected to the other three patients – the index case, another adult and an 8-month-old infant.

In Allegheny County, Pennsylvania, health officials reported this week that the source of an outbreak there was a traveler from India who arrived in the United States on March 7, 2009. Initial exposures occurred at Children’s Hospital of Pittsburgh.

The number of confirmed measles cases in southwestern Pennsylvania now totals six, with additional probable cases awaiting confirmation.

State and county investigators from both states have contacted thousands of people who might have been exposed to measles to assess each person’s risk. While most of those exposed have been found to be vaccinated against the disease, some non-immune people have been asked to stay home until they are cleared of risk. – by Colleen Zacharyczuk

The threat of measles from imported cases is a real one. Measles is only a plane ride away. All children need routine immunization against measles. It is highly contagious disease and causes serious illness in children with a number of severe complications.

– Kathryn Edwards, MD

Infectious Diseases in Children Editorial Board member

The ongoing reports of measles across the United States, including Maryland and Pennsylvania, illustrate well how, in this global world where folks can arrive in any community in the country from literally anywhere in the world in less than a day, we cannot let down our guard when it comes to vaccine-preventable diseases. Measles kills children. Parents should do everything in their power to protect not only their child but their neighbors as well, and the way to do that is to be fully immunized.

– David Kimberlin, MD

Infectious Diseases in Children Editorial Board member

These reports add to the continuing list of outbreaks of measles associated with importations to the United States. Last year a child who contracted measles in Switzerland infected eight contacts followed by a second generation of three additional cases. Eleven were unimmunized, including three who were too young and eight whose parents claimed religious objections. Four were infected in a pediatrician's office. Seventy children had to be quarantined.

During the first seven months of 2008 there were 131 cases of measles, at least 15 of whom had to be hospitalized. Sixteen were younger than 12 months. Of the 95 patients eligible for vaccination, 63 were unvaccinated because of their or their parents? philosophical or religious beliefs.

One of the worst outbreaks in recent years was in 2005 when there were 34 cases in an unvaccinated religious community.

Going unprotected is not without risk. In a study done several years ago we found that in a school with only 4% of the students unimmunized, the introduction of a case of measles resulted in several generations of cases. One cannot and should not depend upon herd immunity. In addition, when cases occur they expose some who are too young to be immunized and who are at greatest risk. Some pediatricians refuse to have patients unprotected continue in their practice because of the risk of exposing their other patients to infections that are preventable. Those physicians cite instances such as the San Diego experience where children too young to be immunized were infected in the waiting room. Finally, children who are unimmunized may be quarantined and excluded from school.

– Philip A. Brunell, MD

Infectious Diseases in Children Chief Medical Editor