Tarrant County Public Health has confirmed the first positive measles cases in Tarrant County.

According to TCPH, the cases involve an adult and a child, both unvaccinated household members. The agency said the source of the infection had not been determined.

While contagious, the two individuals visited Methodist Mansfield ER, 2700 E. Broad St. in Mansfield, from 8 p.m. on April 29 to 3 a.m. on April 30.

TCPH, in a news release, said it is investigating potential additional exposure sites and contacts.

Individuals who were at Methodist Mansfield ER during that timeframe should monitor for symptoms until May 20, particularly if they are unvaccinated or immunocompromised, according to TCPH.

People who visited the location during the specified times should:

• Review their immunization and medical records to determine if they are protected against measles infection.
• Contact and notify their health care provider as soon as possible about a potential exposure if they are pregnant, have an infant, or have a weakened immune system, regardless of vaccination history.
• Monitor themselves for illness with fever and/or an unexplained rash from four days to 21 days after their exposure (the time period when symptoms may develop).
• If symptoms develop, stay at home and avoid school, work, and any large gatherings. Call a health care provider immediately. Do not enter a health care facility before calling and making them aware of your measles exposure and symptoms. The health department can assist health care providers in appropriately diagnosing and managing your care.

The symptoms of measles include:

• High fever, up to 105°F
• Cough
• Runny nose
• Red, watery eyes
• Sore throat
• Rash: typically appears 3–5 days after initial symptoms, starting on the face and spreading downward

While most people's symptoms improve, about 1 in 5 unvaccinated people who get measles will be hospitalized. About 1 out of every 1,000 children with measles will develop brain swelling that can lead to brain damage, and up to 3 of every 1,000 children who become infected will die, the CDC says.

The largest outbreak so far this year has been in West Texas, but cases have been reported in other states around the country as well.