In just the last 48 hours health officials say five cases of measles have been confirmed in southern Texas, including four children under the age of 2. County officials were working to confirm that the woman had been vaccinated.
Measles is an airborne disease which is highly contagious but it is preventable.
"People that are actually infected with measles, one in four will get hospitalized and one in 1,000 may die", said Dana Beckham, director of Harris County Public Health. The outbreak in Clark County has been concentrated mostly among unvaccinated children.
Even though Arizona does not now have a reported case of measles, the state has one of the highest rates of exemptions for at least one vaccine that's required for childcare, kindergarten or sixth grade.
"These outbreaks are associated with travelers who brought measles back from Israel and Ukraine, where large measles outbreaks are occurring", the CDC says.
Rita Espinoza, the chief epidemiologist at Metro Health, said health care providers, emergency rooms and school districts are among those that need to remain vigilant, even though Bexar County has not seen a case of measles since 2007.
"While this is a relatively small number of cases, it's a good time to make sure you and your children have gotten the recommended two doses of measles vaccine", Van Deusen said. Measles can be exceptionally risky for young children and infants. Forty-two patients were not immunized against the virus, while health officials had not verified the immunization status of six patients. The last was in Houston in 2018, according to the county's health department.
Espinoza said the measles, mumps, and rubella vaccine, or MMR vaccine, is 97 percent effective.
Symptoms include a high fever, coughing, runny nose and watery, red eyes between seven and 14 days after infection, the U.S. National Library of Medicine says.