The Houston Health Department said Friday it has identified two cases of measles in adults who've recently traveled internationally, the first cases in Houston since 2018.
The adults live in the same household, and it's unknown whether they're up to date on the vaccine that protects against measles, mumps and rubella, the health department said.
Health officials are still investigating and performing contact tracing to identify anyone else who may have been exposed, the health department said.
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"Measles is a serious but entirely preventable disease," Dr. David Persse, the health authority for the city of Houston, said in a news release. "Vaccination is the best tool we have to protect individuals and the broader community from this highly contagious illness. Ensuring your immunizations are up to date is critical, especially in light of these recent cases."
The health department said it will provide information about any locations, dates and times where anyone might have been exposed to measles on its website.
Anyone exposed to measles should isolate immediately, because the virus can be spread up to four days before a rash appears and up to four days after it's gone. They should also contact their health care provider to arrange testing and monitor their symptoms, the health department said.
Measles is a highly contagious virus that spreads through coughing, sneezing or just being near someone who is infected. The virus can also linger in the air for up to two hours. Up to nine of 10 people who are around measles will become infected if they are not protected by vaccination, according to the U.S. Centers for Disease Control and Prevention.
Symptoms of measles include high fever, cough, runny nose, red and watery eyes and a rash that typically begins on the face.
It can also lead to serious health complications. One in five unvaccinated people who are infected will need to be hospitalized, and one in 20 children will develop pneumonia, according to the CDC.
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Those at highest risk for serious health complications include infants and children younger than 5, pregnant people and people with weakened immune systems.
Two doses of the MMR vaccine are about 97% effective at preventing measles, according to the CDC. The agency recommends the first dose for children 12 to 15 months old and the second at 4 to 6 years old.
About 86% of children in Houston received an MMR vaccine by the time they were 2 years old in 2022, according to CDC data from the National Immunization Survey. That lagged overall rates in Texas, where about 90% of kids received a vaccine by age 2.
"Vaccination not only protects you, but it also helps shield those who cannot be vaccinated, such as young infants and individuals with certain medical conditions," Persse said in the news release.
Vaccines are available through health care providers and at pharmacies, the health department said. Vaccines are available to uninsured people through the Vaccines for Children and Adult Safety Net programs. For more information, visit the Houston Health Department website or call 832-393-5427.