Credit Rosselkhoznadzor
#17,529
It's been nearly two weeks since the first reports of sick and dying cats in Poland began to emerge - and while initially it was assumed that cats were coming in contact with the virus from predation of birds, or from environmental exposures - we've seen reports of indoor cats from several cities testing positive as well.
Yesterday's announcement (see Poland's National Veterinary Institute Genome Sequence Analysis Of H5N1 Viruses Detected In Cats), stated early testing has suggested that the feline H5N1 avian influenza viruses analyzed so far originate from a single, unidentified source.
While there may be more than one route of infection, with dozens of indoor and outdoor cats affected, H5N1 contamination from raw poultry has to be considered. For the past 20 years we've seen multiple outbreaks in zoos around the world which have fed large cats (tigers, lions, etc.) contaminated raw poultry.
This, of course, shouldn't happen in Europe, where there are strict laws to prevent the entry of H5N1 contaminated poultry into the food chain. But of course, no system is foolproof.
Overnight the Polish press has embraced this new possibility as practically confirmed (see here, here, and here), igniting a firestorm in the poultry industry, raising public concern, and earning a rebuke from leading scientists.
To be clear, as of now the possibility has neither been confirmed or ruled out.
We can get some badly needed clarity from the following joint statement, posted on Twitter, by Virologists Krzysztof Pyrć, Maciej Grzybek & Łukasz Rąbalski. I'll have more after the break.
Statement.
Ladies and Gentlemen, in tomorrow's Gazeta Wyborcza An article based in part on our work is to be published. Since the text contains an over-interpretation of the results of our research , which distorts the meaning of the results obtained and can lead to panic and losses, both economic and image-related, today we decided to make our position public and present the actual interpretation of the data . Sincerely, Krzysztof Pyrć, Maciej Grzybek, Łukasz Rąbalski Possible transmission paths of the H5N1 virus. With regard to the transmission of influenza A H5N1 virus from birds to domestic cats, an assessment of the situation has shown that food is one of the likely routes of transmission of the pathogen. This is indicated by: (a) the sudden appearance of the virus in indoor and outdoor cats in different parts of the country; (b) no outbreaks of infection with cat-to-cat transmission; (c) analysis of the genome sequence of the virus collected from the cat showed no drastic changes compared to the reference sequences, suggesting the emergence of a new strain of influenza virus that effectively infects cats; (d)the sequence similarity of viruses that have been isolated from cats in different parts of Poland is very high, which suggests a single source of infection; (e) discussions with cat owners have suggested raw meat may be the source.
To test this theory initially, we asked the owners of affected cats to submit samples of the meat they ate. As a result, we received five meat samples for testing and conducted molecular tests for the presence of the virus. The analysis showed that one of the 5 samples contained the virus. Further analysis showed that the meat contains not only the genetic material of the virus, but also the infectious virus – we were able to isolate the virus in cell cultures.While it cannot be ruled out that the virus found its way into the meat samples later, or even the meat was contaminated by the owners with the virus developing in the cat's body, it is also possible that the raw meat was the source of infection.
It would not be surprising, because already in 2007, a case of contamination of frozen duck meat with the H5N1 virus was reported [1] which caused outbreaks of the disease in Germany. In view of the above, it seems reasonable to appeal to the veterinary services and sanitary inspection to examine the meat available in Poland and consider including meat testing for H5N1 influenza. This is crucial not only because of cats, but also because this virus is a threat to human life. In addition, the Polish poultry industry accounts for almost 20% of the EU market, and the estimated value of meat exports is over EUR 3 billion. It is worth imagining the consequences for this sector of the economy, if it actually turned out that contaminated meat ended up in France, Italy or Germany. The research is conducted by three teams led by prof. dr hab. Krzysztof Pyrć, dr hab. Maciej Grzybek and Dr. Łukasz Rąbalski. [1] Harder TC, Teuffert J, Starick E, et al. Highly Pathogenic Avian Influenza Virus (H5N1) in Frozen Duck Carcasses, Germany, 2007. Emerging Infectious Diseases. 2009;15(2):272-279. doi:10.3201/eid1502.080949.
Long time readers may recall that in 2017 tons of H5N8 contaminated poultry products were shipped from a single infected turkey farm in the Rostov region of Russia sparking a massive months-long operation to remove potentially tainted products from their food chain.
A few blogs on that incident include:
The following year (2018) an outbreak of avian H5N8 led Bulgaria To Recall 1 Million Eggs Due To HPAI H5N8. Despite the theoretical risk of human infection, and the likelihood that many of these poultry products were consumed, no human infections were reported after these events.
We've also seen contaminated chicken sold in shops in Hong Kong (see Hong Kong FEHD Finds Another Shop Selling H5 Contaminated Poultry), and many outbreaks of H5 and H7 avian flu have been traced to wet markets in Asia.
Since there have been human infections with H5 viruses reported following the slaughter, preparation, or consumption of poultry in Asia - and there are studies suggesting that H5 viruses can remain viable in frozen meat for months (see Appl Environ Microbiol: Survival of HPAI H5N1 In Infected Poultry Tissues) - contamination of the food supply is a plausible, albeit uncommon, route of infection.
Poland's National Poultry Council has angrily denounced the media reports (see excerpt below):
NATIONAL POULTRY COUNCIL CHAMBER OF Commerce
Warsaw, July 4, 2023
STATEMENT
In connection with the publication by Gazeta Wyborcza of a material containing a number of unverified and unconfirmed information, from which even the authors of the research quoted in the text distance themselves:
1. We demand that you stop publishing information that is not reflected in the official announcements of state services. Current scientific knowledge does not allow for an unambiguous link between fed poultry meat and the occurrence of H5N1 avian influenza in domestic cats. The previous announcements of the Chief Veterinary Officer and the National Veterinary Institute - National Research Institute in Puławy indicate that at the moment the source of infection has not been determined;
We'll need more facts before this can be sorted out. Food chain contamination remains a plausible explanation, but that doesn't necessarily make it the right (or only) explanation.
Stay tuned.
