Denver has confirmed a second measles case — and the third in Colorado this year — but the patient was already in quarantine and unlikely to infect anyone else, public health officials said Wednesday.
The newly identified case was a person who lived in the same household as a Denver baby diagnosed with measles earlier this month.
The Denver Department of Public Health and Environment didn’t provide any details about the patient, other than that they stayed in quarantine during their contagious period, which is generally four days before and after the measles rash appears.
The first Denver patient, who was too young to receive the vaccine, visited Denver Health’s emergency room on April 6. The health department advised unvaccinated people who sought care there at the same time to monitor themselves for symptoms, which can include a fever, cough, runny nose and red eyes.
Measles symptoms can start up to three weeks after exposure, so Denver won’t know definitively if anyone else caught the virus from the first patient until the end of the week. About 90% of people who don’t have immunity to measles will catch it if they are in the same location as a contagious person.
The state also has had two other cases this year: an adult patient in Pueblo who visited Mexico and an adult in Archuleta County who didn’t leave the state. No other cases had a link to the Pueblo patient, and so far, no one appears to have gotten sick from contact with the Archuleta County patient.
One dose of the measles vaccine is about 93% effective in preventing the virus, and two doses are 97% effective. People who survived measles also generally have lifelong immunity, but doctors don’t recommend catching it, because of the risk of pneumonia and neurological complications.
Nationwide, 800 people have gotten measles so far this year, with about three-quarters of those cases happening in Texas.
Two children and one adult died of complications from the virus.
Sign up for our weekly newsletter to get health news sent straight to your inbox.