The world must work up endeavors to prevent huge infectious disease outbreaks - such as flu strains that can jump from animals to humans - which could kill millions of people, the chief of the UNs disaster risk agency said on Saturday. Head of the United Nations Office for Disaster Risk Reduction Robert Glasser warned that the use of vaccine technologies and disease surveillance is very low across most of the world because the dangers posed by pandemics are "out of sight, out of mind". "Weve had the emergence of new viruses and viruses are mutating all the time, like avian influenza, SARS ... people are not generally aware of them because they are hazards that dont strike very often," Thomson Reuters Foundation quoted him as saying. "But when they do strike, they can be enormously devastating," Glasser said on the sidelines of the World Urban Forum - the worlds biggest conference on urban issues. "In this area, there is so much work to do." Different strains of bird flu spread across Europe, Africa and Asia over the last year, leading to large-scale slaughtering of poultry in certain countries and some human deaths in China. The number of viral strains circulating and causing infections has reached unprecedented levels, experts say. Their greatest fear is that a deadly strain of avian flu could then mutate into a pandemic form that can be passed easily between people - something that has not yet been seen. "This could lead to millions of deaths globally," said Glasser, who will leave his post at the end of the month. The World Bank last year launched a "pandemic bond" to support an emergency financing facility to release cash quickly to fight a major health crisis such as the 2014 Ebola outbreak. The catastrophe bond, which will pay out depending on the size of the outbreak, its growth rate and the number of countries affected, is the first of its kind for epidemics. Glasser said general disaster risk reduction efforts are too often top-down and focused on global issues and policy talks. Yet huge progress is still being made on the ground - such as reducing the death toll from huge disasters, he added. Better early warning systems and community involvement in evacuation planning have helped countries such as Bangladesh and Mexico soften the blow of cyclones and hurricanes, Glasser said. "What weve seen over the past decade is a steady drop in loss of life from major hazards that strike."