(CNN)Hundreds of factory workers at a fish processing plant in Ghana have tested positive for the coronavirus, the country's president Nana Akufo-Addo said.
All 533 of them contracted the virus from one worker at the factory in the port city of Tema, the president said in his public address to the nation Sunday.
The factory infection was detected from a backlog of 921 samples collected for testing last month that health officials just reported, Akufo-Addo said.
He did not give further details about the operations or measures to be taken about the situation.
CNN has reached out to Ghana's health ministry for comment and is awaiting a response.
The mass infection at the facility brings the total number of confirmed cases in the West African nation to 4,700, the president said, adding that 22 people have died of coronavirus-related illnesses since the outbreak was reported in the country in March.
Akudo-Addo said cases have continued to increase due to improved testing, saying the "more people we test for the virus, the more persons we will discover as positive."
Ghana has carried out more than 160,000 tests and it has added seven more testing centers to speed up turnaround time.
The president extended the existing ban on public gatherings and said schools and borders across the country would remain closed.
Last month, the president lifted a three-week lockdown in its key cities, saying its coronavirus testing had improved and also to reduce the effect of the restrictions on the country's poor.