Africa is in danger of losing the war against deadly sleeping sickness-carrying tsetse flies, a UN expert warned, adding that total eradication by sterilising male flies using radioactive rays was the only viable option. Ali Boussaha, head of the African division at the UN International Atomic Energy Agency told IRIN on Monday that attempts to control the spread of the tsetse-transmitted trypanosomosis had not worked in Africa, but the new Sterile Insect Technique (SIT) could be a success.