This morning, we noted the locations where the D.C. Department of Health said a woman infected with measles traveled inside the District. It’s been subsequently pointed out to us that our language might have been a little misleading: if you were at those locations on February 21, you should at least double-check to make sure that you have been vaccinated and go see a healthcare provider. Symptoms of measles generally do not appear until 7 to 18 days after infection, although in some cases, symptoms take three weeks to appear — but a person infected with measles is most contagious during the first four days they carry the infection. So even if you don’t have any symptoms — fever, red eye, cough and a red blotchy rash on the face — after riding the bus or eating at the Potbelly in Columbia Heights that day, you could be passing along the infection, especially if you didn’t get the two-dose vaccination as a kid. (Not sure where your vaccination records are? Consider it an excuse to call your mom.)