Coronavirus has reached prisons in Guinea and Sierra Leone, government officials said Tuesday, raising the spectre of outbreaks in unsanitary and overcrowded jails.

Bouna Yattassaye, the deputy director-general of Guinea’s National Health Security Agency told AFP that authorities had discovered an infection in the capital Conakry’s central prison.

He did not specify whether an inmate or a guard had been infected, but said the agency had “identified the measures to be applied urgently”.

Guinea – with some 1 200 confirmed Covid-19 infections, and seven deaths – is struggling to curb the spread of the disease across the nation of about 13 million people.

Rights groups say its prisons are often disease-ridden and overcrowded.

Conakry central prison, for example, has a capacity of 500 inmates but currently houses some 1 500, according to Amnesty International.

There were also earlier suspicions of prison infections in the former French colony.

Guinea’s justice ministry restricted prison visits on April 24, for example, following three penitentiary deaths whose causes were not known by Tuesday.

Neighbouring Sierra Leone has also recorded a positive prison case, the government said in a statement on Monday.

A man detained on April 17, on unspecified charges, fell ill three days later and was transferred to hospital.

“During his admission he confessed that he escaped from a quarantine centre,” the government said in the statement.

In response, authorities have closed the section of the prison where the infected inmate was held, moving the other prisoners and placing them under observation.

The former British colony has recorded 99 coronavirus cases to date, with four fatalities. It has also decided to suspend criminal courts for a month in a bid to curb prison infections.

Guinea and Sierra Leone were hard hit by West Africa’s 2014-2016 Ebola outbreak, which claimed thousands of lives in both countries.