The two human cases of bird flu infection in Cambodia were not transmitted by the patients to one another, according to public health experts.

The Cambodia Ministry of Health announced Friday that the two recently reported cases of H5N1 avian influenza in Prey Veng province were not caused by “human-to-human transmission,” local English-language newspaper Khmer Times reported.

“Both cases have been concluded as H5N1 virus transmission from poultry, and this event is not a human-to-human transmission,” a spokesperson for the agency said in a statement to local media to clarify the speculations and shut down fears that the virus was already capable of transmitting between humans.

Late last month, Medical Daily learned about an 11-year-old girl who died at a hospital in Cambodia’s capital city Phnom Penh about a week after falling sick with the virus. She reportedly got ill on Feb. 16 and was sent to the hospital for treatment but did not survive after suffering symptoms, including a high fever, cough and throat pain.

The other case was the girl’s father. Officials only found out about his infection while investigating the case and conducting tests in the area where the girl resided. The spokesperson confirmed they also tested 51 samples from other humans, including 20 close contacts and 31 with flu-like symptoms. But the results were negative for the virus.

“The investigation team is still on standby for active case finding and will collect samples for testing from individuals with influenza-like symptoms,” the spokesperson added.

The Associated Press reported that the girl’s father tested positive the day after her death. He was isolated until he no longer displayed flu symptoms and was only released after testing negative for bird flu three times.

Local health officials, the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) concluded that the two infections were spread by poultry and not through transmission between the parent and the child.

“While further characterization of the virus from these human cases is pending, available epidemiological and virological evidence suggest that current A(H5) viruses have not acquired the ability of sustained transmission among humans, thus the likelihood of sustained human-to-human spread is low,” WHO said in a statement, as quoted by The BMJ.

Avian influenza is known to typically infect birds and poses little threat to humans because the virus is incapable of binding to cells in human respiratory tracts very effectively. However, experts warned against complacency since viral spillovers from animals to humans are not impossible.

Historically, avian influenza has infected hundreds of people. A WHO report previously revealed that the virus has a 56% case fatality rate after recording 135 deaths from the 240 total cases of human infection recorded since January 2003.

Bird Flu (6)
A French farmer looks at ducks in their cage at a poultry farm in Doazit, Southwestern France, December 17, 2015. REUTERS/Regis Duvignau