Pueblo County hadn’t experienced a measles case since the 1990s. That’s until last month, when it reported the first case of measles in Colorado.

That may be why the urgent care facility that saw the county’s first measles patient in three decades delayed reporting the case, said Trysten Garcia, a Pueblo Department of Public Health and Environment spokesperson.

“It’s not something that always remains top of mind for our health care providers,” Garcia said.

Results at a commercial lab — such as the one that tested this case — could take up to 10 days, Garcia said.

On Monday, state health officials reported Colorado’s first measles case, adding to outbreaks in 20 other jurisdictions as the United States total surges toward 500 cases and the largest spike since 2019.

An unvaccinated 21-year-old in Pueblo contracted measles after traveling to an area in Mexico experiencing an outbreak, according to the Colorado Department of Public Health.

The infected person worked at the Southwest Deli and Café from March 17 to March 21. They developed a rash the following day, on Saturday March 22, and sought care at the Southern Colorado Clinic at 109 South Burlington Drive.

Generally, patients are infectious four days before and after presenting with a rash.

Clinic officials waited nine days to report the case.

“We have taken every precaution to ensure the safety of our patients and staff,” said Holly Herring, Southern Colorado Clinic’s chief operating officer.

Herring added: “We reported it as soon as we had the results.”

The county health department, Herring said, did not indicate that the urgent care facility had delayed reporting.

Part of the clinic’s safety precautions included Personal Protective Equipment and placing the patient in a negative pressure room to prevent the spread, Herring said. Staff, who are vaccinated, have been offered an anti-body test to check their immunity levels.

Measles is a respiratory illness transmitted through direct contact with infected droplets or airborne when a person breathes, coughs or sneezes. The virus can linger in the air for up to two hours after a cough or sneeze. Symptoms typically emerge within two weeks of exposure. A telltale sign of measles is a spotty red rash that starts on the face and spreads to the neck and trunk to the rest of the body.

In rare cases, measles can cause swelling of the brain and death.

Measles is one of the most contagious diseases. Just one individual can infect up to 18 others, according to the World Health Organization (WHO). To put that into context, that means measles is more contagious than COVID-19 (up to three people with the original strain), polio (up to seven) and chickenpox (up to 12).

To provide what’s called “herd immunity” — which happens when enough people in a community are immune to a disease either through infection or vaccination — greater than 95% of people need to be vaccinated to prevent measles from spreading.

The City of Pueblo has an 84% vaccination rate against measles for children younger than 5 and 92% in the county, Garcia said. The rate for school-age children is 95% in the city and county.

According to the latest state health department data, 94% of Colorado students last school year were fully vaccinated against measles, mumps and rubella — all of which are contagious viral diseases that can cause serious health problems.

Health officials are encouraging anyone at the Deli or clinic during this time to monitor their symptoms for 21 days after exposure and consider avoiding public gatherings.

Measles was declared eradicated in the U.S. in 2000. Health officials credit the nation’s highly effective vaccination program. Before a vaccine was developed in the 1960s, an estimated 48,000 Americans were hospitalized with measles and 500 died each year.

Colorado has had just seven measles cases since 2014, state data shows. Most years, the state doesn’t report any.

“I think that the lesson learned here for everyone is that there is often ignorance in the case of measles,” Garcia said.

Measles cases in the U.S. peaked in 1990 with 27,808 infections, according to the Centers for Disease Control and Prevention (CDC). The last major case spike was in 2019 when there were 1,274 measles cases over the course of the year.

CDC officials maintain that the risk for widespread measles in the U.S. remains low. While a booster is not yet recommended, the CDC is encouraging all Americans be up-to-date on their vaccinations.

Those with a measles, mumps, and rubella (MMR) vaccine or who were born before 1957 — when the disease was so widespread everyone exposed to the virus developed natural immunity — are generally considered immune.

The bulk of the cases nationally have been among either unvaccinated patients or those who have an unknown status.