Biography of a Measles Outbreak

Wondering how a vaccine-preventable disease outbreak can spread? Wired offers a clear-eyed view from the Arizona measles outbreak. As parents facing the choice about whether to immunize our children, we owe it to them to understand the truth about the presence of vaccine-preventable diseases in our country and communities, how they get here, and how they spread. You can read the story of the Arizona measles outbreak here, but below you'll find an excerpt from the play-by-play of how that outbreak unfolded. If any non-vaccinating parent has told you that these diseases are effectively gone in the United States, and that immunization is unnecessary, take a look at how measles spread in Arizona. Please also take special note of two facts: one, that the outbreak was started by an adult who had traveled to another country and returned to the United States and two, that many of the victims were children who had intentionally been left unvaccinated as well as infants who had not had a chance to be vaccinated:


In February 2008, a 37-year-old Swiss woman who had never been vaccinated against measles arrived in Tucson after a visit to Mexico. She developed breathing problems and a rash and went to a local hospital’s emergency room. They suspected she had a viral illness and admitted her.

Here’s what you have to know, to understand what happened next. Measles is extremely contagious; up to 90 percent of unvaccinated people who are exposed to it will get it. And if someone nearby has it, youwill get exposed — because coughed-out measles virus can travel across a room, and hangs in the air for hours. The best protection against spreading measles in a hospital is putting someone in a negative-pressure isolation room, which is engineered so no air can leak out into the rest of the hospital. It took two days to get the Swiss tourist into isolation, because measles is rare enough in the US that it was not the hospital personnel’s first thought.

Meanwhile:

A 50-year-old woman who had spent an hour in the ER at the same time as the Swiss woman caught the disease from her. Patient 2 got taken care of, went home, and started feeling feverish nine days later. She had difficulty breathing and thought at first she was having an asthma attack, so she went back to the hospital and was admitted for two days. That she had measles would not be discovered until six days after that.

While she was  in the hospital, Patient 2 unknowingly infected a 41-year-old health care worker who took care of her — and who was scheduled to get a measles-vaccine booster shot that very day, because the hospital was also caring for the tourist. Patient 2 also passed measles to an unvaccinated 11-month-old boy who was in the same ER while she was waiting to get checked for asthma, and to two unvaccinated siblings — 3 and 5 years old — who were visiting their mother on the same hospital floor after Patient 2 was admitted.

Patient 3, the health-care worker, passed measles to a 47-year-old woman in her emergency department — who later  ended up in an intensive care unit with measles pneumonia — and later to a 41-year-old man in his home. Patient 4, the toddler, gave the virus to an unvaccinated 1-year-old while they were both in the same pediatrician’s office. Five other people were infected somewhere in their everyday lives: a 2-year-old boy who had never been vaccinated and who also ended up in an ICU with seizures brought on by high fever; a 9-month-old and an 8-month-old, also unvaccinated; and two adults, 35 and 37, who might have gotten one dose as children, but had no documentation of receiving a second dose.

Those 14 are just the confirmed cases. In addition to them, there were 363 suspected ones, and today’s paper makes clear authorities believe there were more illnesses than they know. And for every known case, there were dozens or hundreds of exposed people who had to be checked: 145 passengers on the tourist’s flight from Mexico, 1,795 patients in the ER that treated Patient 2, 25 people who attended church with Patient 7, 10 kids in the same day care center as Patient 8.