Seven members of a family in Indonesia have been diagnosed with avian flu, prompting investigators from the World Health Organization to frantically track down anyone else that may have been in contact with them. This is the "mother of all clusters," according to WHO regional spokesperson Peter Cordingley. To date, the WHO says there is no evidence that the virus has spread beyond the family into the general community but that human-to-human transmission cannot be ruled out. Many avian flu experts believe that one of the most likely possible causes of widespread human-to-human transmission will be a mutation of the H5N1 virus. So far, genetic sequencing on the Indonesia virus has not shown that the virus has mutated in any way. Six of the family have died, and it is believed that another member of the family may also have died from avian flu, but she was buried before samples were taken.