The World Health Organization has declared Ghana's first outbreak of the Ebola-like Marburg virus disease after labs confirmed the infections in two cases announced earlier this month.

The disease — an infectious haemorrhagic fever in the same family as Ebola — is spread to people by fruit bats and transmitted among people through direct contact with bodily fluids of infected people and surfaces, the WHO said. 

A preliminary analysis of samples from two patients from Ghana's southern Ashanti region — both of whom died and were unrelated — turned up positive, but were forwarded for full confirmation to the Institute Pasteur in Dakar, Senegal.

The UN health agency lab corroborated the results from the Noguchi Memorial Institute for Medical Research in Ghana, the WHO said in a statement Sunday.

The first case was a 26-year-old male who checked into a hospital on June 26 and died on June 27.

The second was a 51-year-old male who went to the hospital on June 28 and died the same day, the WHO said, adding that both men sought treatment at the same hospital.

"Health authorities have responded swiftly, getting a head start preparing for a possible outbreak," said WHO regional director for Africa Dr Matshidiso Moeti.

"WHO is on the ground supporting health authorities and now that the outbreak is declared, we are marshalling more resources for the response."

More than 90 contacts, including health workers and community members, have been identified and are being monitored, the WHO said.

Marburg is potentially very harmful and deadly: Case fatality rates in past outbreaks have ranged from 24 per cent to 88 per cent.

This outbreak marks only the second time that the disease has been detected in West Africa.

Guinea confirmed a single case detected in August, according to WHO. The outbreak in Guinea was declared over five weeks later.

Previous Marburg outbreaks and individual cases have appeared in Angola, Congo, Kenya, South Africa and Uganda, the WHO said.