DENVER — Denver7 is learning more about the widespread impact one person infected with measles has had on our state after three more cases of the highly contagious disease were discovered in the last week.
So far, there's been a dozen cases reported in different counties across the state. Taking a closer look at the Denver metro area, there have been three locations where a measles exposure was possible in the last week.
The incubation period for measles is about 7 days to 21 days, according to the Colorado Department of Public Health and Environment.
Where have people been exposed recently?
In Windsor, people may have been exposed at the King Soopers located at 1520 Main St. on Saturday, May 31, between 10:30 a.m. to 1:15 p.m. According to state health department officials, they should be on the lookout for symptoms until June 21.
In Denver, the individual may have exposed shoppers and staff at the Trader Joe’s located at 661 Logan St. in Denver’s Capitol Hill neighborhood on Thursday, May 29, between 9:30-11:40 a.m. They should be looking for symptoms until June 19.
And in Glendale, the individual may have exposed people at the Target located at 4301 E. Virginia Ave. on Monday, June 2 from 9:20-11:50 p.m. They should be keeping an eye out for symptoms until June 23.
How to tell the difference between allergies or the beginning stages of measles infection
"The typical symptoms would start with fever, cough, red, watery eyes, runny nose, that's usually the beginnings of it, and followed, on average, for three to four days later with a rash. And the typical rash starts on the head and neck and then spreads down over the rest of the body," said Bob Belknap, director of the Public Health Institute at Denver Health.

While some of the early on symptoms could be mistaken for allergies, Belknap told Denver7 a hint might be if you typically don't experience those types of allergies and if you're not vaccinated against the measles.
Denver7 has been closely following confirmed cases of measles in Colorado amid a multi-state outbreak of the virus in the U.S. this year. Check out some related stories in the links below.
- Colorado health officials address use of vitamin A after state reports first case of measles amid US outbreak
- Colorado health officials recognize 'challenging' reporting delays as number of measles cases tick up
- Colorado pediatrician shares how to protect children amid rise in measles cases
Nearly half of all measles cases in Colorado are adults who were vaccinated. We asked Belknap, how that could happen?
"I think something we have known for a while is that breakthrough cases can happen in people who have been vaccinated. They happen when there's been really a pretty significant exposure to someone who is sick, and that's what we're seeing in this instance," he said. "It was people who were exposed over a very long international flight, or some folks who were exposed in a fairly packed indoor setting at DIA. In some sense, the fact that we haven't seen more cases as a result of that exposure speaks to the effectiveness of the vaccinations."
For anyone who has been to any of the possible exposure locations, Belknap said no one is truly in the clear until 21 days have passed without any symptoms.
"People are not going to be infectious to others if they don't have symptoms. It's really if someone begins to develop symptoms, then that's the point at which, if they have measles, they could be contagious," he said.
If you believe you could be infected with measles, call your healthcare provider first. Do not show up at an appointment without notifying them of the possibility of a measles, so they can coordinate the best way to avoid any exposure with others.
