#18,041 A little over 17 years ago in this blog - in Cats and Dogs and Flies, Oh My! - we looked at a 2006 study (see Detection and isolation of highly pathogenic H5N1 avian influenza A viruses from blow flies collected in the vicinity of an infected poultry farm in Kyoto, Japan, 2004 by Kyoko Sawabe et al.) that found that at least 2 types of flies could carry the H5N1 virus. While flies weren't believed infected with the virus, they could ingest (and subsequently regurgitate or defecate) infected material, or potentially spread it mechanically by their feet or body, thereby spreading ..read more

  #18,040 Despite nearly 30 years of dealing with H5N1, we have an unfortunate habit of underestimating what the HPAI H5Nx virus is capable of.  In the early 2000s, the virus was believed to be restricted to Southeast Asia, since the nearly everybody `knew' that sick migratory birds don't fly.  Even after the virus winged its way to Europe, the Middle East, and Africa (following the 2005 Qinghai Lake event ) many experts still doubted the ability of the virus to spread efficiently via migratory birds (see 2014's Bird Flu Spread: The Flyway Or The Highway?). This peculiar ..read more

#18,039 On Monday, May 6th,  the World Health Organization will hold a new live Epi-Win Webinar on the public health risk of H5N1 recently found in American Cattle. A little over a year ago they held a webinar on H5N1 which you can view at this link.  Although this is a rapidly evolving situation, and everyone is working with limited data, this should be an illuminating presentation.  The time of the webcast (13:00 CET) works out to 7am EDT in the United States. Registration is required for the Zoom call, but the video will be posted on the WHO's YouTube Channel someti ..read more

  #18,038 On a number of occasions we've discussed how difficult it would be for even a well-equipped western nation to monitor for - and detect - novel influenza cases in the community.     A year ago, in UK Novel Flu Surveillance: Quantifying TTD, health authorities estimated the TTD (Time To Detect) a novel H5N1 virus in the community - with aggressive testing - to take several weeks.  We are now more than a month since the first human H5N1 infection linked to infected dairy cattle was reported (see CDC Statement & Risk Assessment On The Texas H5N1 Case ..read more

  CDC Nowcast #18,037 While COVID has taken a back seat to other infectious disease concerns the past few weeks, and rates of infection appear to be currently low in the United States, it continues to evolve into new, and potentially worrisome variants.  Despite this ongoing evolution, over the past 2 years the world has intentionally dismantled the bulk of their global surveillance, testing, and reporting system in order to `move on' from the pandemic emergency (see No News Is . . . Now Commonplace). The most recent WHO Update (Apr 12th) indicates: Globally, the number of new ..read more

  #18,036 As we have discussed repeatedly over the years, the superpower of influenza viruses is its ability to reinvent itself via reassortment; the swapping of genetic material between two influenza viruses co-infecting a single host.  Since HPAI H5N1 arrived in North America in late 2021, it has reassorted repeatedly with other avian viruses which are native to this part of the world. As a result, instead of having one H5N1 virus to contend with, we have scores of genotypes circulating in the wild. Each genotype can have different capabilities, with some being more pathogenic in ..read more

#18,035 The news on the safety of pasteurized dairy products following the detection of H5N1 in dairy cattle continues to be reassuring, with the FDA reporting yesterday that after analyzing nearly 300 retail mild samples they were unable to culture the virus in any of them.  Additionally the FDA reports being unable to detect H5N1 RNA in retail powdered infant formula and powdered milk products.  The big concern continues to be the consumption of `raw milk' or unpasteurized dairy products.  And while there are laws on the books in most states to discourage the practice, the ..read more

  Today (Weds May 1st) I'll be away from my desk having 3 small skin cancers (the result of living under the Florida sun for much of my 70 years) removed from my scalp and face by Mohs surgery. Depending on what they find, this could be an all-day affair.  All three are squamous cell, so the prognosis is excellent.  In any event, I don't expect to be able to blog today, but I hope to be back tomorrow. In the meantime, you can check in with FluTrackers and with CIDRAP or Crof for the latest infectious disease news.  Cheers, and thanks aga ..read more

  #18,034 Other than a story in Sky News last week which reported the UK was not planning on testing cows for HPAI, we've seen very little comment outside of North America on the detection of HPAI H5N1 in dairy cattle in the United States.   Yesterday, however, the UK's DEFRA (Department for Environment, Food & Rural Affairs) published a risk assessment (below), which finds the risks of something similar affecting UK cattle very low.  They base their assessment on the fact that the B3.13 genotype found in US cattle was created from the European H5 virus reassor ..read more

A growing, but incomplete, picture of affected States #18,033 The CDC's EID Journal published an expedited research paper today on preliminary findings into the infection and spread of HPAI H5N1 clade 2.3.4.4b among both cattle and domestic cats in the United States.    Infected cattle appear to suffer relatively mild, nonspecific illness, but shed copious amounts of the virus in their milk. Cats, however, often develop severe neurological manifestations leading to rapid death , similar to what we've seen with other mammals (see PrePrint: HPAI H5N1 Infections i ..read more