LAGOS : Nigeria on Saturday said it has trained 800 volunteers to fight Ebola as fears rose that the worst-ever outbreak of the deadly disease could spread across Africa's most populous nation. Authorities in Nigeria's megacity Lagos last week appealed for volunteers to make up for a shortage of medical personnel because of a six-week doctors' strike over pay. ‘People have heeded our call for service,’ said Hakeem Bello, a spokesman for Lagos State Governor Babatunde Fashola.‘We have trained some 800 volunteers in the area of contact tracing, sensitisation and treatment of the Ebola disease.’ Four people have died and six more are infected by Ebola in Nigeria as part of the worst-ever outbreak of the deadly virus, which has killed 1,145 people across west Africa this year. Experts say Ebola is raging out of control in the region, and the UN World Health Organization has declared the epidemic an international health emergency and appealed for global aid.The disease erupted in the forested zone straddling the borders of Guinea, Sierra Leone and Liberia earlier this year and spread to Nigeria last month. The districts of Kailahun and Kenema in eastern Sierra Leone have become the new epicentres of the outbreak, with charities and health authorities there scrambling to contain the spread of the disease. ‘You cannot mess about here: this virus will kill you. One mistake, one wrong move, and you're dead - that's it,’ a senior aid worker in Kailahun told AFP.But officials fear an outbreak in the key regional hub of Nigeria could be far more dangerous, and US health authorities pledged this month to send extra personnel and resources to Africa's most populous country. Volunteers have so far been deployed to 57 districts of Lagos state but more are needed, particularly to treat those already infected with the disease, Bello said. Lagos' state government has stepped up a media campaign to raise awareness of how to prevent the spread of the disease, including radio and television advertisements and public health announcements.Nigerian doctors have been on strike nationwide since July 1 to demand a pay rise and better working conditions. Medical charity Doctors without Borders, known by its French acronym MSF, on Friday warned Ebola is spreading faster than authorities can handle and could take six months to bring under control. Draconian travel restrictions have been imposed across west Africa and several airlines have cancelled flights to affected countries in a bid to stop it spreading beyond the region.Scottish health officials on Saturday confirmed that a woman, reportedly from Sierra Leone, who fell ill at a deportation facility south of Glasgow has tested negative for the virus. Nigeria has also withdrawn its athletes from the Youth Olympics in the Chinese city of Nanjing as a result of the outbreak, state media reported as the games opened on Saturday. The International Olympic Committee has barred athletes from Ebola-hit countries from competing in pool events and combat sports, affecting three athletes.Ebola is spread by contact with an infected person's bodily fluids such as sweat and blood, and no cure or vaccine is currently available. The last days of a victim can be grim, characterised by agonising muscular pain, vomiting, diarrhoea and catastrophic haemorrhaging described as ‘bleeding out’ as vital organs break down. Canada and the United States are both sending consignments of largely untested drugs in the hope of saving hundreds of lives, but officials warn they are likely to have little impact.Nigeria's first fatality was Liberian government employee Patrick Sawyer, who brought the virus to Lagos, sub-Saharan Africa's largest city, on July 20. He died in hospital on July 25. Nigeria has not recorded a case outside Lagos but there were fears that a nurse who contracted Ebola from Sawyer may have carried the virus to the key southeastern city of Enugu.