Twelve health workers at the Aminu Kano Teaching Hospital (AKTH) have tested positive to coronavirus on Saturday.
The Joint Health Sector Union (JOHESU) said its AKTH branch confirmed the new cases of health workers infected by the virus.
Chairman of the branch, Dr Murtala Isa Umar, in a statement listed the affected workers as five nurses, three technicians, one medical information officer, one billing officer and one attendant.
Thirteen other workers tested negative, Umar said.
Twenty-two JOHESU members who had earlier tested positive for COVID-19 are currently in isolation centres.