Testing was ordered after one of two twins died of respiratory failure three weeks after being born at the Las Vegas-area Summerlin Hospital. The mother of the babies, Vanessa White, 24 died July 1, a month after the death of the newborn. An autopsy revealed White had tuberculosis.
The other twin died Aug. 1 of TB.
Health officials said they believe the children contracted TB from their mother, who was allowed to visit the twins without wearing a mask.
Officials said 142 infants in the Neonatal Intensive Care Unit at the same time as the twins were tested for TB but none tested positive. TB testing for infants is not considered reliable until they are 1 year old, KLAS-TV, Las Vegas, reported. Health officials recommended the infants be given antibiotics as a precaution.
Officials said 22 healthcare workers were diagnosed with tuberculous. One had an active infection and the others were being monitored as "latent" individuals who could come down with the disease later.
The cost of the district's investigation is expected to exceed $200,000, KLAS said.
A state report released in November cited Summerlin Hospital for not taking basic precautions to prevent the outbreak.