(LAS VEGAS) -- Nevada health officials are testing 140 newborns who they believe were exposed to tuberculosis at a Las Vegas hospital.
A mother and her newborn twins died of tuberculosis at Summerlin Hospital over the summer, prompting an investigation by the Southern Nevada Health District.
Letters went out to hundreds of patients in August, but after hospital employees tested positive for the disease, officials started calling families to get tested immediately.
"It wasn't, 'Oh, come in next month.' They want you in this week," Jessica Hammond told KTNV. Her newborn son was in the neonatal intensive care unit at the same time as a baby who later died of tuberculosis. "Our concerns are, was he exposed? Is he carrying anything? Are we as well?"
Hospital staff didn't realize the infected woman had tuberculosis until after she and one of the twins died and they performed an autopsy, according to KTNV. The other twin was in the NICU being treated without being under quarantine.
The second twin also tested positive for tuberculosis and died in August, health department spokeswoman Stephanie Bethel told ABC News.
Though the initial investigation found that no other babies had contact with the infected patient, further monitoring of the situation revealed that the infection spread to hospital staff in the NICU, according to a health department statement.
Of the hundreds of babies, parents and hospital staff members who were possibly exposed to the disease, 26 people have tested positive for tuberculosis, including two employees with active infections that need to be isolated, Bethel said. The other 24 people have latent tuberculosis, meaning they will need to take medications to make sure they don't' become sick, but they are not contagious.
No babies have tested positive for tuberculosis so far, she said.
The health department is continuing to test people who were possibly exposed to tuberculosis in the NICU, Bethel said. Additional test results will be available in a week or a week and a half.
Tuberculosis is caused by a bacterium that typically attacks the lungs and can be fatal if not treated properly. It's spread through the air when the infected person "coughs, sneezes, speaks or sings" and another person breathes in the bacteria, according to the U.S. Centers for Disease Control and Prevention. Symptoms include a bad cough that persists for three weeks or longer, fatigue, chest pain and coughing up blood.
Copyright 2013 ABC News Radio