A U.S. citizen in Ghana is being tested for Ebola, which has killed nearly 500 people in West Africa this year.

Ghana's Health Ministry said over the weekend that a patient was quarantined at the Nyaho clinic in the capital, Accra, while tests were underway at a local medical institute.

Reports on Monday from Accra said the patient was an American man who had recently visited Guinea and Sierra Leone, two countries fighting to contain the regional Ebola outbreak.

In a statement, Ghana's health ministry said it had taken precautionary measures at the Nyaho clinic to keep the Ebola virus, if present, from spreading. It urged the public to remain calm and said it has the situation under control.

West African ministers met in Accra last week to discuss the Ebola crisis. The World Health Organization says the disease has killed 481 people in Guinea, Liberia and Sierra Leone.

The WHO says traditional practices such as home-based care and a mistrust of authorities are undermining efforts to stop the outbreak.

The often-fatal disease is spread between humans by direct contact with blood or other bodily fluids from an infected person.

There is no specific treatment or vaccine for Ebola. Before this year, the deadliest Ebola outbreak was in 1976 in the Democratic Republic of Congo, where 280 people died.