On 23 February, Cambodian health authorities notified the World Health Organization (WHO) of a human case of avian influenza (H5N1). We are talking about an 11-year-old girl from the province of Prey Veng in southern Cambodia. On February 16, 2023, he developed symptoms and received treatment at a local hospital. On February 21, 2023, he was admitted to the National Children’s Hospital with severe pneumonia. One sample was collected the same day through the Severe Acute Respiratory Infection sentinel system and tested positive for avian influenza A (H5N1) virus. The sample was also sent to Cambodia’s Pasteur Institute, the National Influenza Center, who confirmed the discovery. The patient died on February 22, 2023.

Authorities have looked into the girl’s close contacts and found a second case, a family contact, of which the WHO specified that she was notified on 24 February 2023. The UN health agency says an outbreak investigation is underway, including determining exposure to the virus in these two reported cases.

These are the first two cases of avian influenza A (H5N1) reported in Cambodia since 2014, according to WHO. In December 2003, Cambodia first reported an outbreak of highly pathogenic avian influenza (HPAI) H5N1 affecting wild birds. From then until 2014, sporadic human cases were reported in Cambodia due to transmission from poultry to humans. H5N1 infection in humans can cause severe illness, has a high mortality rate, and is notifiable under the IHR (2005).

“Nearly all cases of human infection with influenza A (H5N1) have been associated with close contact with infected live or dead birds or with influenza A (H5N1) contaminated environments. Based on the data available to date, the virus does not infect humans as easily, and human-to-human transmission seems unusual. An outbreak investigation is currently underway, which includes identifying the source of the virus in two reported cases. As the virus continues to be detected in poultry populations, more human cases can be expected,” the WHO said in a statement.

Economic Impact of Avian Flu

Europe is experiencing the largest avian influenza epidemic on record to date, with more than 6,000 outbreaks reported in 37 countries. This animal disease can significantly affect all kinds of birds.

Recently, the Castile-La Mancha Ministry of Health reported that a worker at a poultry farm in Guadalajara tested positive for H5N1 avian influenza, a case followed by a second case a few days later, according to the WHO. Fortunately, the workers’ cases were false positives. The virus was in the nostrils of the workers who were sampled, but they did not become infected.

Influenza viruses are highly volatile and have been of concern to epidemiologists and virologists for many years due to their potential to jump and spread among humans.