A maternity-ward nurse with the Santa Clara Valley Medical Center in San Jose, Calif., reportedly exposed more than 1,000 people, including 350 infants, to tuberculosis.

Hospital officials say they have notified all patients who were potentially exposed to TB after an active case of the disease was diagnosed in a nurse, The New York Times reports.

The employee who worked “in the area of the newborn nursery” had been given the diagnosis, with the potential to infect hospital staff and patients between August and November, hospital officials said.

Dr. Stephen Harris, the chairman of pediatrics at the hospital, said in a statement that the risk of infection remained low but that “the consequences of a tuberculosis infection in infants can be severe.” He said the hospital would offer preventive treatment to the exposed infants “as soon as possible.”