Measles Outbreak Highlights Potential for Spread in Health Care Setting

Widespread immunization has made outbreaks of highly contagious diseases rare in the United States, but occasional introductions of disease from abroad and spread among those who lack immunity continue. A recent measles outbreak described in the Jan. 20 edition of Morbidity and Mortality Weekly Report (MMWR) provides a stark reminder of the potential consequences of vaccine refusal and the vigilance required of health care providers to prevent such occurrences from growing out of hand.

On March 28, 2009, the Pennsylvania Department of Health (PADOH) was notified of a measles case involving an unvaccinated, 23-month-old child, and within five days, four other cases were reported—the original patient’s four-year-old brother and father, an 11-month-old infant, and a physician. All five patients had been in the same hospital emergency department (ED) on March 10, and a review of other patients who had been in the ED that day turned up a 10-year-old boy, recently arrived from India, who had been discharged after treatment for fever and rash. This patient subsequently tested positive for measles as well. An investigation of the six patients’ 4,000 contacts found no additional cases.

The father of the two children had received a single dose of measles vaccine as a child, but the children had received no vaccination against measles by parental choice. The physician had received three doses of measles vaccine, the 11-month-old infant was too young to have received the vaccine, and the original patient’s vaccination history was unknown. Troublingly, the hospital-reviewed employee health records found that, among the 168 potentially exposed employees, 72 (43%) had no documented measles immunity.

“This outbreak highlights the potential for measles transmission in health-care settings,” the MMWR article reads. “Healthcare providers should be aware of measles symptoms and should be vigilant about suspecting the disease and appropriately isolating patients, especially those with a history of international travel.”

The article adds that, in order to cut down on the risk of transmission, all physicians should be familiar with the signs and symptoms of measles, ask for the travel histories of patients suspected of having any infectious disease, and effectively isolate potentially infectious patients. Also, hospital employees should have documented immunity to measles. Employees without evidence of measles immunity should be offered vaccination in accordance with Advisory Committee on Immunization Practices and Hospital Infection Control Practices Advisory Committee recommendations.