An employee of the World Health Organization (WHO) who contracted Ebola in Sierra Leone will be flown to the German city of Hamburg for treatment, a spokesman for the city said.

Rico Schmidt, spokesman for the Hamburg Health Senate, said the patient would arrive later on Wednesday and be treated at Hamburg university clinic's tropical medicine institute. The WHO in Geneva said the patient was a Senegalese epidemiologist.

One of the deadliest diseases known to man, Ebola is transmitted by contact with body fluids and the current outbreak has killed at least 120 healthcare workers.

The WHO has deployed nearly 400 of its own staff and partner organizations to fight the epidemic of the highly contagious hemorrhagic fever, which has struck Sierra Leone, Liberia, Guinea and Nigeria.

On Tuesday, it said it had shut a laboratory in Sierra Leone after a Senegalese medic there became infected.

At least 1,427 people have died and 2,615 have been infected since the disease was detected deep in the forests of southeastern Guinea in March.