 Bird flu may be the tip of the iceberg. Experts meeting in Mali say the deadly H5N1 virus is just one of a plethora of diseases threatening animals and people around the world as global warming, intensive farming, increased travel and trade help dangerous microbes breed and spread. "Avian flu is just one of many diseases that are impacting the continent (of Africa). The experts are telling us that other diseases are going to emerge or re-emerge," said Francois Le Gall, the World Bank's lead livestock specialist for Africa. "Almost every year there is a new disease appearing, and 75 percent of these emerging or re-emerging diseases are coming from animals; 80 percent of those have zoonotic potential," he said in an interview. Le Gall said such zoonoses -- animal diseases that humans can also catch -- included Rift Valley fever, rabies and anthrax. "These could come together to create what the experts are calling 'the perfect microbial storm'," he said. But Le Gall said progress being made to tackle the current bird flu outbreak by strengthening veterinary and human health monitoring systems around the world would temper the risk of an apocalyptic conflagration of diseases. "All the measures we are using now are going to be useful to control all these emerging or re-emerging diseases -- like veterinary services, public health services," he said. What singles out bird flu is the potential of the virus to mutate into a human form of influenza capable of passing from person to person, not just from infected animals. International health experts were winding up a three-day meeting in Mali, the fourth global bird flu summit since late last year, aimed at plotting strategies to halt the spread of the disease and seeking donor funds for this campaign. "Remember that with globalisation, and unprecedented movements of merchandise, of people, there is a continuous transfer of pathogens," Bernard Vallat, director general of the World Organisation for Animal Health, told Reuters. "This is made worse by climate change. Many disease vectors have colonised new territories," Vallat said. Some diseases were being spread by mosquitoes or other insects whose larvae were previously killed off by cold winters, but who now survive in temperate zones, he said. "Unfortunately, there are plenty of examples. There is a disease called blue tongue, which infects sheep, which for the first time in history has attacked northern Europe, the Netherlands, Belgium, Germany, and by a vector that is capable of spreading the virus in this region, which is unprecedented." Blue tongue spreads via biting insects, but does not affect humans. But West Nile Disease, which affects birds and was first found in Egypt and is spread by mosquitoes, has killed hundreds of people in the United States since it first spread there in 1999 -- probably via an imported pet bird, Vallat said. "Now the United States is completely infected, as well as southern Canada and Mexico. In a few years this disease which was completely unknown (there) has colonised all the eastern United States via a mosquito vector," he said. "Microbes can cross the world in a few hours," he said. "The globalisation of exchanges of people, merchandise and commodities is a phenomenon that affects the whole planet more and more each year. It's a good thing, but it brings with it new risks. We have to be prepared."