Factory infection was detected from a backlog of 921 samples taken for testing last month that health officials have just reported, said Akufo-Addo.
He did not give more details on the operations or the measures to be taken regarding the situation.
CNN has contacted the Ghanaian Ministry of Health for comment and is awaiting a response.
Mass infection in the facility brings the total number of confirmed cases in the West African nation to 4,700, said the president, adding that 22 people have died from coronavirus-related illnesses since the outbreak in the country in March.
Akudo-Addo said cases have continued to increase due to improved testing, saying “the more we test the virus, the more positive we find.”
Ghana has performed more than 160,000 tests and added seven more test centers to speed up the turnaround time.
The president extended the current ban on public gatherings and said schools and borders across the country would remain closed.