After the death of an eleven-year-old girl from bird flu in Cambodia, fears of greater human-to-human transmission were initially unfounded. The girl’s father also tested positive for the H5N1 bird flu virus, but not eleven other contacts of the girl, some of whom had flu symptoms, said the World Health Organization (WHO) in Geneva.

The father, who showed no signs of illness, is in isolation in a hospital. It is the first bird flu infection in Cambodia since 2014.

The largest outbreak of avian influenza ever documented is currently raging across several continents. Avian influenza, also known as bird flu, is an infectious disease that mainly affects waterfowl and other birds. Experts fear that the virus is adapting more and more to mammals and could therefore also become more dangerous to humans. Infections had also been detected in mammals such as sea lions, raccoons, foxes, bears and martens in recent months.

“According to what is known so far, the virus does not easily infect humans and human-to-human transmission appears to be uncommon,” the WHO said. In Cambodia, the investigation is ongoing into how exactly the father and daughter were infected. An unusual number of dead wild birds have reportedly been found in the area where they live in recent weeks.