DES MOINES, Iowa -- Financial aid and global co-ordination are needed to prevent the Ebola health care crisis from becoming a food emergency, agriculture ministers from West African nations at the centre of the Ebola outbreak said Thursday.

In Sierra Leone, where thousands are infected and more than 900 have died, 40 per cent of the farmers have abandoned their fields, said Joseph Sam Sesay, minister of agriculture, forestry and food security.

Coffee and cocoa beans amount to about 90 per cent of the country's agricultural exports, and the region where they are grown has been struck hard by the virus.

"Farms have been abandoned. Some families have been wiped away. Some villages have been wiped away. It is very serious," Sesay said. "We have to understand that agriculture is the mainstay of our economies. If agriculture is down our economies will be down."

Sierra Leone's economy was expected to grow more than 11 per cent this year until Ebola struck in May. Now growth is only predicted to be around 3 per cent, he said.

Liberia Agriculture Minister Florence Chenoweth says billions of dollars of outside agricultural investment is gone because farming has been decimated.

Liberia expected 9 per cent economic growth but has ratcheted it down twice to about 2 per cent, Chenoweth said. The nation had attracted $17.6 billion of foreign investment of which $7 was for agricultural development but those investors have left, she said, adding that a recovery plan has been developed.

"We are very determined, very resilient people," she said. "We have not as ministers of agriculture put forward a recovery plan for nothing. We will implement that plan ... and rebuild our country's agricultural sector."

Kanayo Nwanze, president of the International Fund for Agricultural Development, a United Nations agency based in Rome, said the Ebola epidemic is strangling regional trade and could "lead to a hunger crisis of epic proportions for West Africa."

International food and medical assistance is needed to stem the spread of Ebola, he said.

"It is unfortunate that the international community does not look up to crises when they occur in what I call the forgotten world, the invisible world where people die in rural areas from drought or disease until it grows out of proportion or until it begins to effect the larger international community," Nwanze said. "When there's a crisis in Timbuktu it doesn't stay in Timbuktu anymore. Nowadays it reverberates in Paris, London, Berlin, and Washington."

The officials spoke Wednesday at the World Food Prize Foundation annual meeting in Des Moines where government, academic, corporate, non-profit agriculture and food experts gather to discuss issues of hunger and boosting agricultural productivity.