The evolution of the measles outbreak in Clark County, Washington is going pretty much by the book.
An unvaccinated person, in this case a seven-month-old who was too young to get the MMR vaccine, got infected with measles while traveling out of the country. They came home and spread the infection to someone else who is not immune.
People in Clark County may have thought they were off the hook since they had not heard of another case of measles since news of the first case back on Feb. 14, but they likely forgot that measles has a long incubation period. Although it averages 10 to 12 days, the incubation period from the time of exposure to someone who is sick until the onset of measles symptoms can be anywhere from 7 to 18 days.
Now that there is another suspected case of measles in Clark County, an unvaccinated school age child who had contact with the first measles case at a local pediatrician's office, the 7 to 18 day clock starts over to see if there will be more cases. And there could still be more cases from the initial measles exposure too.
People could have been exposed to this second measles case:
- at his school on Feb. 26 (Vancouver Christian School)
- on Feb. 28 at a 7-Eleven grocery store at 5101 N.E. 112th Avenue in Vancouver from 4 p.m. to 8 p.m.
- at his doctor's office on March 2 (Southwest Medical Group at Fisher's Landing)
With at least five cases of measles in Boston, two in Washington, two in Arizona, and one in New Mexico, in the past month, you have to wonder we are simply getting off to a fast start or if this is going to be a record year for this vaccine-preventable disease.