At the end of last week I visited Liberia and Sierra Leone, two of the poorest countries in sub-Saharan Africa, and also the most affected by the Ebola outbreak.

Ebola has taken over 1,500 lives in West Africa, three-quarters of them in those two countries. And the pace appears to quicken: 40 per cent of the cases have appeared in the past three weeks.

Both countries have declared states of emergency; the placards on the streets of Monrovia and Freetown bear the message that for as long as we still seek a cure for the virus, then prevention is the best cure.

Presidents Ellen Johnson-Sirleaf and Ernest Bai Koroma have shown determination and leadership, being calmly efficient in mobilising all forces to tackle the crisis.

They are grateful for the help and solidarity of the international community, especially Médecins sans Frontières and the US-based Centres for Diseases Control, but they need additional medical personnel and healthcare workers. They expressed the desire to manage the outbreak themselves.

“It’s our disease; it’s our country,” Liberian Health Minister Dr Walter Gwenigale told me on Wednesday.

Any and all help is still needed, and the African Development Bank is channeling its support through the World Health Organisation. Our support will help recruit and train health workers, purchase equipment and medicines, and ensure that the necessary logistics are in place at the local level to provide emergency health services to Ebola patients.

Dedicated staff are risking their lives every day. A tenth of all confirmed Ebola cases in Liberia are health workers, mostly nurses, mostly women. WHO officials told me that 23 out of 25 nurses in the Redemption Hospital in New Kru Town, Monrovia, contracted the virus and died.

The two remaining nurses kept coming back every day, to continue their work. Volunteers from the community filled the vacant spots, to provide much needed care and support to the sick.

With this type of dedication and co-ordination, I am left in no doubt that together we shall be able to halt the spread of the disease. Ebola will be controlled.

Yet my concern is that another crisis is looming, a serious and longer-term economic crisis that could be born not out of facts, but fear.

It is misconceptions outside these countries that could threaten to cancel out the economic achievements inside them, over the past 10 years since both emerged so strongly from civil war.

In Sierra Leone, President Koroma expressed growing concerns regarding the economic consequences of the epidemic. Closing borders makes transport and trade increasingly difficult, he said. He regretted that critical investments in the mining and tourism sectors are on hold.

Against the recommendations of the WHO, airline companies are cancelling flights to and from affected countries. The major West African ports of Dakar and Abidjan have forbidden shipments to affected countries, restricting their tonnage capacity.

These measures bear more than an economic cost; they prevent even emergency medical supplies from reaching the countries.

Around 50 tonnes of emergency medical supplies are held at Brussels airport, ready to be flown to West Africa, and into action in the fight against Ebola. There are passenger waiting lists in all three countries.

In Liberia, President Sirleaf shared with me her concerns about food security. Ebola has hit at harvest time, disturbing both planting and reaping. It hit hardest in the rice growing regions.

Liberia already imports 60 per cent of its rice, and will now need to bring in even more. GDP growth will fall far below the projected 5.9 per cent, and revenues may be down by 20 per cent.

Investments are slowing down, and with them the possibilities of job creation in a country in which just one in five people has an assured salary. Schools have already been closed for three months, and will in all likelihood remain so.

We need to act fast to prevent an economic crisis and a food security crisis in West Africa.

I am appealing to political leaders and business people in Africa not to let a pandemic of fear affect the economies, the livelihoods and the very futures of those countries affected by Ebola. Borders need to be reopened. Planes need to start flying again. Trade needs to resume.

We need to isolate Ebola, not the countries.

Dr Donald Kaberuka is president of the African Development Bank.