Avian influenza A (H5N1) virus, commonly known as bird flu, is a viral infection that primarily affects birds. However, it can also infect humans and cause severe respiratory illness, and even death, in some cases. Recently, two human infections with the H5N1 virus have been reported in Cambodia, with one of the patients tragically dying. In this article, we will delve into the details of these cases and discuss the ongoing investigation to identify the source of the infections and detect any potential additional cases.
What is H5N1 Bird Flu?
Avian influenza A (H5N1) virus is a type of influenza virus that primarily affects birds. It is highly contagious among birds and can spread rapidly through bird populations. H5N1 virus can also infect humans who come into contact with infected birds or surfaces contaminated with their droppings, saliva, or nasal secretions. Human infections with H5N1 virus are rare but can be severe, with a mortality rate of about 60%.
The Cases in Cambodia
Two cases of H5N1 bird flu were reported in Cambodia in early 2023. The cases involved a child and her father, who lived in the same household. The child, a 10-year-old girl, reportedly developed symptoms on January 28 and was admitted to the hospital the next day. She died on February 3, and laboratory tests later confirmed that she had been infected with the H5N1 virus.
The father, a 43-year-old man, reportedly developed symptoms on February 1 and was admitted to the hospital the same day. He was diagnosed with pneumonia and tested positive for the H5N1 virus on February 4. He received treatment and was discharged from the hospital on February 18.
Investigation and Findings
An investigation is currently underway to determine the source of the infections and detect any potential additional cases. According to the Cambodian Ministry of Health, preliminary genetic sequencing has identified the viruses as H5 clade 18.104.22.168c, which have been circulating in Cambodia among birds and poultry for many years. These viruses have resulted in rare sporadic human infections in the past, but these two cases are the first such infections reported in Cambodia since 2014.
The 22.214.171.124c viruses in Cambodia are different from H5N1 viruses currently circulating in wild birds and poultry in the United States and other countries, which are H5 clade 126.96.36.199b.
Risk of Human-to-Human Transmission
To date, no indication of person-to-person spread of H5N1 virus has been found in Cambodia. Both patients had reported exposure to infected birds and poultry before becoming ill. However, the possibility of human-to-human transmission cannot be completely ruled out, and health officials are monitoring closely for any further cases.
Public Health Response
The Cambodian Ministry of Health has taken several measures to contain the spread of H5N1 virus. These include:
- Conducting active surveillance to detect any additional cases
- Enhancing biosecurity measures in poultry farms and markets
- Conducting public awareness campaigns to educate the public about the risk of bird flu and how to prevent it
The recent cases of H5N1 bird flu in Cambodia are a stark reminder of the ongoing threat posed by influenza viruses that circulate in animals. Although human infections with H5N1 virus are rare, they can be severe and can result in death in some cases. The ongoing investigation to determine the source of the infections and detect any potential additional cases is crucial in containing the spread of the virus.