After a father and daughter were diagnosed with bird flu, officials in Cambodia scrambled to test nearly a dozen of their contacts for infection the H5N1 virus, which has been causing mass die-offs of birds worldwide. The daughter, an 11-year-old, has died, but the World Health Organization said on Friday that 11 contacts have so far tested negative for the infection.
Why the concern? While hundreds of human cases have occurred over the years, scientists have become increasingly concerned that the virus one day may become adapted to people. Any evidence of human-to-human transmission would accelerate worries that a new pandemic could be on the way.
Most experts believe that the cases in Cambodia were likely caused by direct exposure to infected birds. At the moment, the risk to most people remains low, they say.