Does bird flu pose a threat to human beings? The WHO, in its literature on avian influenza, states that humans can be infected with virus subtypes H5N1, H7N9 and H9N2. In a recent instance of human infection, a one-year-old was confirmed to have H5N1 in Lao PDR, thought to have been acquired from backyard birds kept by the family. Infection in other birds in the region was also confirmed. On the H5N1 virus, the WHO says, “Human cases of H5N1 avian influenza occur occasionally, but it is difficult to transmit the infection from person to person. When people do become infected, the mortality rate is about 60%.”