When a single imported case of measles led to a small outbreak in Tucson, AZ, two hospitals were forced to spend about $800,000 to contain it, with much of the cost tied to ensuring the immunity of health care workers. The 2008 incident and ensuing investigation serves as a cautionary tale as the United States struggles with its largest number of measles cases since 1996.
In the first 19 weeks of 2011, 118 measles cases were reported. Most (89%) were related to importation of measles from other countries. Nine outbreaks accounted for almost half (49%) of the cases. And the consequences were serious. Forty percent of the patients with measles required hospitalization, according to a report by the Centers for Disease Control and Prevention.
“Measles is quite severe,” says Jane Seward, MD, MPH, deputy director of the Division of Viral Diseases at the CDC and an author of an analysis of the Tucson outbreak. Hospitals need to consider a diagnosis of measles if a patient presents with a cough, fever and rash, she says. “Unvaccinated travelers coming into the United States continue to pose a risk,” she says.
Indeed, the Tucson case began with a 37-year-old traveler from Switzerland who was unvaccinated. She went to a hospital emergency room in Tucson on Feb. 12, 2008 and again the next day, when was admitted with fever and rash. Yet measles wasn’t initially suspected and she wasn’t isolated until two days later.
Meanwhile, a 50-year-old woman who was exposed to the Swiss traveler in the emergency department waiting room developed a fever and respiratory illness. At first, she was diagnosed with asthma exacerbation, then pneumonia and allergic drug reaction. Finally, on March 2, she was diagnosed with measles.
Measles spread from that second patient to several other people. A health care worker, who had just received her MMR vaccine the day she cared for Patient 2, developed fever on March 5 and fever, cough and rash by March 9. An unvaccinated 11-month-old boy who was in an emergency department room across the hall from Patient 2 developed measles, as did two unvaccinated children, ages 3 and 5, who walked past the patient’s room while visiting their mother in the hospital.
In all, there were seven cases that were confirmed as health care-associated – linked to the index case. Another five developed community-acquired cases and one person who developed measles was exposed to a patient in his home. Of 11 patients who sought medical care at a hospital or physician’s office for fever, cough and rash, only one was masked and isolated.
That delay in suspecting measles is a consequence of the success in controlling measles in this country, but measles is raging elsewhere in the world. France and India were responsible for the greatest number of imported cases in the United States this year.
The outbreak investigation involved 4,793 hospital or clinic patients and 2,868 health care workers. Only 75% of the health care workers at the two hospitals that received patients with measles had evidence of immunity. None of the Tucson hospitals had electronic records that enabled them to quickly determine if their employees were vaccinated or otherwise immune.
Of 1,583 health care workers who had serologic testing, 11% were found to be seronegative. Meanwhile, health care workers without evidence of immunity were vaccinated and furloughed for five to 21 days after their last exposure.
The furloughs alone cost the two hospitals about $444,000, according to the analysis of the outbreak.
“Hospitals can be prepared by just having the evidence [of vaccination or immunity] on file,” says Seward. For health care workers born before 1957, “they can choose to vaccinate them, routinely or they can have it on file that they need to be vaccinated in the event of an outbreak,” she says.
Special update from our sister publication, Hospital Employee Health