A “serious incident” has been declared by a hospital trust after an outbreak of tuberculosis (TB).
Brighton and Sussex University Hospitals NHS Trust said a staff member contracted the bacterial infection from a patient and passed in on to another patient.
Some 321 patients and 745 staff who may have come into contact with the disease have been made aware of the signs of the infection, the trust said.
Nearly 400 people had been screened and no active cases have been identified.
The disease mainly affects the lungs and is spread through inhaling tiny droplets from coughs or sneezes of an infected person, but usually after prolonged exposure.
Symptoms include a persistent cough that lasts more than three weeks, weight loss, fever, and swellings in the neck.
The trust, which oversees hospitals in Brighton and Haywards Heath, did not disclose the hospital in which the “unique, unexpected transmission” occurred.
It added that it was a “strain of TB not routinely seen in hospitals” and said it was working closely with Pubic Health England and the London School of Hygiene and Tropical Medicine.
A spokesman for the trust said: “Transmission of the infection was not linked to any deficiencies in care and our management of this incident has received the support of both Public Health England and the TB centre at the London School of Hygiene and Tropical Medicine.
“We have robust plans in place to deal with these issues and help prevent further cases.”