Maricopa County reports 3 measles cases. Here's what Arizonans need to know about symptoms, vaccines

Health officials in Maricopa County have confirmed three related cases of measles, which is a highly contagious and potentially fatal viral infection.

The cases were in an adult and two children, all three were unvaccinated and the individuals are "connected," public health officials said. At least one of the individuals had a recent history of international travel, health officials said.

One of the three was hospitalized but has since been released and all are recovering now, county health officials said. Officials would not say whether the children or the adult were hospitalized. The last time a measles case was reported in Arizona was a single case in 2019. Sixty-seven cases have been reported statewide since 2006.

"It is unusual and it does happen from time to time because mostly what we see are imported cases, so cases that have traveled and have come back," said Dr. Nick Staab, Maricopa County Department of Public Health epidemiologist. "We are concerned because measles is so contagious. ... If you are unvaccinated and exposed to someone with measles, it's very likely that you will get measles."

County health officials are conducting case investigations and contact tracing on all three cases. Measles can linger in the air for up to two hours and it's so contagious that about 90% of unvaccinated individuals who are exposed will become infected, health officials say.

"The real key to preventing this from becoming an epidemic is what happened in the last 48 hours before diagnosis, and figure out how bad the exposures were and among who," said Will Humble a former state health director who's executive director of the Arizona Public Health Association.

"The exposures could have happened among a very well vaccinated cohort of people but probably not. ... Most of the time if you have an unvaccinated mom or dad and two unvaccinated kids, that's the concerning thing. Their friend groups are probably unvaccinated, too."

Staab said county officials are still working to identify people who may have been exposed and would not say whether either of the infected children were in school.

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What are symptoms of measles?

Officials with the Maricopa County Department of Public Health are encouraging health care providers to be on the lookout for fever and rash among unvaccinated patients, especially if they have a known exposure. Health care providers are required to report suspected cases of measles to their local health department.

"This is not one of those diseases that you want to try to get so that you are immune afterwards. It does lead to hospitalization," Staab said. "There could be severe pneumonias. And even if you completely recover from measles there's still a chance that years down the road you could have severe complications."

About 90% of kindergarten students in Maricopa County were fully vaccinated against measles during the 2021-2022 academic year, Staab said. But that's an average, so some areas may have lower coverage than others. 

State data shows just 29% of kindergarten classes in Maricopa County public schools during the 2021-2022 academic year had community immunity against measles, which would leave many children vulnerable in the event of an outbreak.

Arizona law says children attending school and child care must obtain certain vaccines, unless they are exempted by a doctor for medical reasons, or by a parent for personal or religious reasons.

Community or "herd" immunity generally is considered to be 95% or more people in a group who are fully vaccinated against measles, which means at least two doses of the measles, mumps, and rubella (MMR) vaccine.

"We know that through the pandemic vaccination rates in general have been much lower because kids and families have had a much harder time accessing their medical homes and getting vaccines," Staab said.  “It can be a severe illness, so we strongly encourage anyone who has not been vaccinated to get vaccinated to prevent further spread." 

Symptoms of measles typically appear seven to 12 days after exposure but may take up to 21 days. Symptoms include:

• Fever (101 degrees Fahrenheit or higher)
• Red, watery eyes
• Cough
• Runny nose
• A non-itchy rash that is red, raised, and blotchy. The rash begins after other symptoms, usually on the face at the hairline, and moves down the body. The rash may last five to six days.

Individuals who develop symptoms are encouraged to seek medical care and testing and avoid others. They should call the provider ahead to let them know about symptoms and potential exposure before going in.

The provider or facility will provide instructions on how to be seen without exposing others in the waiting area. Individuals who do not have a health care provider can find a federally qualified community health center or a provider at FindHelpPhx.org.

Adults should make sure they are up-to-date on MMR vaccines

Two doses of the measles, mumps, and rubella (MMR) vaccine typically are given during childhood. The federal recommendation is for children get the first dose at 12 through 15 months of age, and the second dose at four through six years of age.

"If you grew up here (in Arizona), it's very likely that you are vaccinated. ... If you were vaccinated as a child the vaccine is very effective at preventing disease," Staab said.  "If you do not know your vaccination status, getting that single dose of the MMR vaccine as an adult is a good idea, just to make sure that you are vaccinated against measles."

The Arizona Department of Health Services has a tool to help individuals look up their vaccination status here: https://www.azdhs.gov/preparedness/epidemiology-disease-control/immunization/azmyir/index.php

Individuals born before 1957 or who had measles as a child are considered immune. But adults vaccinated after 1957 before 1989 — and particularly those born between 1957 and 1967 — could be more vulnerable, The Arizona Republic reported in 2019.

Between 1963 and 1967, there were two vaccines available — one from Pfizer and one from Merck. And one that was commonly used only had a dead virus, and it turned out it wasn't that effective for producing immunity.

Since many people in that age group don't have their vaccine records, the recommendation really is if that if you were born between 1957 and 1967, providers recommend getting a second dose now, or getting blood work done to test for immunity.

In 1989 the U.S. Centers for Disease Control and Prevention required everyone to get two measles vaccinations, which increased immunity significantly. 

The U.S. declared measles eliminated in 2000, but outbreaks periodically have happened since then. Travelers can bring measles into the U.S. and spread the disease to people who are not protected, which sometimes leads to outbreaks.

In 2008, an unvaccinated Swiss tourist with measles infected 14 people in Tucson and cost two hospitals in that city a total of nearly $800,000.

The costs were associated with containing the outbreak, furloughing exposed workers and administering vaccines. Those infected included an unvaccinated 2-year-old boy who ended up in the intensive care unit for six days with seizures, according to a published account of the outbreak in The Journal of Infectious Diseases.

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Reach the reporter at Stephanie.Innes@gannett.com or at 602-444-8369. Follow her on Twitter @stephanieinnes.

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