Ebola: UN Ebola chief raises 'nightmare' prospect that virus could mutate and become airborne - making it much more infectious

The longer the Ebola epidemic continues infecting people unabated the higher the chances it will mutate and become airborne, the UN's Ebola response chief has warned.

Anthony Banbury, the Secretary General's Special Representative, has said there is a 'nightmare' prospect the deadly disease will become airborne if it continues infecting new hosts.

His comments come as organisations battling the crisis in West Africa warned the international community has just four weeks to stop its spread before it spirals 'completely out of control'.

And the British nurse who survived the disease said the 'horror and misery' of watching young children die from the disease must be avoided 'at all costs'.

Mr Banbury told the Telegraph that aid workers were fighting a race against time amid fears the disease will begin to mutate.

He said: 'The longer it moves around in human hosts in the virulent melting pot that is West Africa, the more chances increase that it could mutate.