Bird flu cases in father and daughter in Cambodia came from poultry, CDC says

US health officials say recent cases of bird flu discovered in two Cambodians, one of them fatal, show no sign of human-to-human transmission.

An 11-year-old girl from a village in southeastern Cambodia died last month after she contracted the H5N1 bird flu virus. Her father also tested positive for the virus.

The US Centers for Disease Control and Prevention analyzed the two cases and released the results on Thursday.

The CDC says their investigation determined the infections were caused by the spread from bird to human.

Health officials say the father and daughter kept domesticated poultry and had opportunities to have contact with infected birds.

The CDC says it did not identify any genetic changes that can cause person-to-person transmission, or reduce susceptibility to influenza antiviral drugs.

The World Health Organization says it has received reports of bird-to-mammal H5N1virus infections, prompting health authorities around the world to step up vigilance.