No human cases of avian flu have been found in India, Egypt or Nigeria but transmission risks remain as long as the virus is present in birds, Reuters quoted a spokesman for the World Health Organization as saying on Tuesday. WHO spokesman Dick Thompson told a press briefing that "a number of people" with flu-like symptoms have been tested for the H5N1 strain in the three countries, where outbreaks have been reported in birds. "We haven't seen human cases out of these investigations so far," Thompson said, adding the top U.N. health agency would keep up surveillance because it was still possible that human infection could occur. "There is really no time frame. As long as the virus is circulating it could jump into humans," he said. Bird flu has been detected in more than 30 countries and territories since 2003 and 170 people are known to have been infected by the virus, of which 92 died, according to the WHO.
