Cambodia H5N1 Case Map & Timeline (2023-2024)

#17,920

Today's report of a 5th H5N1 case in Cambodia in less than a month demonstrates that even after going early a decade without a human case, older disease threats can still stage a comeback.  A reminder that old scourges like SARS-CoV, MERS-CoV, and even avian H7N9 could someday regroup and threaten public health. 

I've put together a map showing the locations and the timeline of Cambodian cases over the past 12 months, one which shows that infections have been spread across 5 provinces, with most of the cases reported from 3 southern provinces (Kampot, Prey Veng, and Svay Rieng). 

Even more striking, the first two cases were reported in February of 2023, which were followed by nearly 10 months without a case.  In October 2 more cases were reported, followed by another two in November. 

While December was quiet, we've seen 5 cases reported since the 4th week of January. 

This acceleration in cases isn't totally unexpected, as avian flu transmission tends to increase during the winter months.  Of course, winter is a relative thing, and in Cambodia January daytime temperatures still often reach the 90s.

Last October we looked at a Preprint: A Timely Survey of Knowledge, Attitudes, and Practices Related to Avian Influenza (H5N1) in Rural, Cambodia, which was published just before the 3rd and 4th cases were announced in 2023, which examined some of the common practices in this part of the world which can increase the risks of H5N1 infection. 

More than 200 (n=208) participants from Prey Veng province were invited to be interviewed face-to-face on their knowledge, attitudes, and practices related to avian influenza.

Although this study was limited both in number of participants, and geographic scope, it is probably fairly representative of the practices of tens, or even hundreds, of millions of people living in this part of the world.

We've seen many of the practices described before, including the consumption or improper disposal of dead poultry, often in connection with H5N1 spillovers.

Convincing people that something they have been doing for generations - like raising chickens in their backyard, or buying live poultry at bird markets - could suddenly be dangerous can be a hard `sell'. 

We've seen similar (and often bitter) resistance to the notion that beloved camels in Saudi Arabia could carry  a new, deadly coronavirus (see Saudi Camel Owners Threaten Over MERS `Slander’).

Over the past few years, fur farms around the the world are suddenly viewed as potential `flu factories' (see PNAS: Mink Farming Poses Risks for Future Viral Pandemics), while some pet owners have had consider the possibility that their companion animals may be at risk from avian flu in the outdoor environment. 

As the level of H5N1 (and other zoonotic viruses) continue to increase around the world, we find ourselves living in a `new normal', where old practices and traditions may need to be reconsidered and modified if we hope to reduce the risk of future outbreaks.