Bird Flu in Cambodia: WHO raises concern over Avian flu cases; Warns more to come

WHO Concerned About Bird Flu Cases: The World Health Organization (WHO) on Sunday announced that Cambodia has reported an outbreak of the avian influenza A (H5N1) virus. The global health agency is investigating the two human cases after an 11-year-old girl died this week and her father also tested positive for the H5N1 strain.

According to WHO, these are the first two cases of avian influenza A (H5N1) reported from Cambodia since 2014.

“In December 2003, Cambodia reported an outbreak of Highly Pathogenic Avian Influenza (HPAI) H5N1 for the first time affecting wild birds. Since then, and until 2014, human cases due to poultry-to-human transmission have been sporadically reported in Cambodia,” the health agency stated.

On 23 February 2023, the IHR NFP of Cambodia notified WHO of a confirmed case of human infection with avian influenza A (H5N1) virus. The case was an 11-year-old girl from Prey Veng province, in the south of Cambodia. On 16 February 2023, the case developed symptoms and received treatment at a local hospital.

On 21 February 2023, the case was admitted to the National Pediatric Hospital with severe pneumonia.

“A sample was collected the same day through the severe acute respiratory infection (SARI) sentinel system and tested positive for avian influenza A (H5N1) virus by the reverse transcriptase-polymerase chain reaction (RT-PCR) at the National Institute of Public Health on the same day. The sample was also sent to Institute Pasteur Cambodia, the National Influenza Center, which confirmed the finding. The patient died on 22 February 2023. Cambodia shared the genetic sequence data of the virus from the index case through the publicly accessible database GISAID. Virus sequencing shows the H5N1 virus belongs to clade 2.3.2.1c, and similar to the 2.3.2.1c clade viruses circulating in poultry in southeast Asia since 2014,” the h

A total of twelve close contacts (eight asymptomatic close contacts and four symptomatic who met the suspected case definition) of the index case were identified and samples were collected and tested. Laboratory investigations confirmed the second case on 23 February 2023, the father of the index child. The father, who is asymptomatic, is in isolation at the referral hospital. The eleven other samples tested negative for A (H5N1) and SARS-CoV-2.

As of 25 February 2023, a total of 58 cases of human infection with avian influenza A (H5N1) virus have been reported in Cambodia since 2003, including 38 deaths (CFR 66%); nine cases and seven deaths between 2003 to 2009 and 47 cases and 30 deaths between 2010 to 2014 were reported, WHO stated.

What is avian influenza A (H5N1)?

Influenza A (H5N1) is the strain of the influenza virus that primarily infects birds, but can also infect humans. According to experts, this type of flu is most often contracted by contact with sick birds. It can also be passed from person to person.

The global health agency stated that almost all Influenza A (H5N1) infection cases in people have been associated with close contact with infected live or dead birds, or Influenza A (H5N1)-contaminated environments.

“Based on evidence so far, the virus does not infect humans easily and spreads from person-to-person appears to be unusual. An outbreak investigation is ongoing including identifying the source of exposure of the two reported cases to the virus,” WHO stated.

The UN Health Agency also warned that since the virus continues to be detected in poultry populations, further human cases can be expected.

From 2003 to 25 February 2023, a total of 873 human cases of infection with influenza A (H5N1) and 458 deaths have been reported globally from 21 countries.

Avian Influenza A (H5N1): Symptoms

Symptoms begin within two to eight days and can seem like the common flu. Cough, fever, sore throat, muscle aches, headache and shortness of breath may occur.

To date, evidence shows that the virus does not infect humans easily and person-to-person transmission appears to be unusual.

Past Outbreaks of Avian Influenza A (H5N1)

• Almost a decade ago, the UN Food and Agriculture Organization (FAO) had issued an urgent warning of an outbreak in southeast Asia of a strain of avian influenza called H5N6.
• In 2015, FAO again raised alarms about a dangerous outbreak of the highly virulent H5N1 strain, which had spread to five West African countries within six months. The agency had appealed for $20 million in emergency funds “to stop it in its tracks” before it affected humans.
• At the time, FAO had said the H5N1 strain has caused the death of tens of millions of poultry and losses of tens of billions of dollars.
• In Cambodia, a 2003 H5N1 outbreak had, for the first time, affected wild birds. Since then, and until 2014, human cases due to poultry-to-human transmission have been sporadically reported in the country.
• As of 25 February, Cambodia has reported a total of 58 cases of human infection with the H5N1 virus have been reported since 2003, including 38 deaths.

Treatment and Prevention

Currently, there is no vaccine widely available to protect against avian influenza in humans. The global Health Agency recommends that all people involved in work with poultry or birds should have a seasonal influenza vaccination to reduce the potential risk of reassortment.

Here are some preventive measures:

• Travelers to countries with known outbreaks of animal influenza should avoid farms, contact with animals in live animal markets, entering areas where animals may be slaughtered, or contact with any surfaces that appear to be contaminated with animal faeces.
• General precautions include regular hand washing and good food safety and food hygiene practices.
• Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival.