I spent the end of last week attending a funeral celebration commemorating the faithful life of my nearly 98 year old aunt in the Midwest. She leaves my 94 year old mother as the sole surviving child of a Nebraska depression-dust bowl era farm family that still sent all 4 kids and nearly all 15 grandchildren through college. It was an inspiring blessing to join my many cousins and 2 brothers in celebrating her life. The pastor described visiting her as meeting Laura Ingalls Wilder in the 21st century. Whenever I feel overwhelmed by challenges we may face, I think back to that young Nebraska family huddled in the cellar waiting out dust storms for several years, before packing it up to begin farming anew in Illinois with help from relatives. Tough times don’t last, but tough people do (well into their 90’s)!
Speaking of tough times, Northwest Iowa has been hit hard by historic rains and ongoing H5N1 dairy cases. The Iowa Department of Agriculture reported Iowa’s 11th infected dairy herd on Saturday in Sioux County, the morning after record floods in the area: 9th case of bird flu in cattle detected in Sioux County, 11th in Iowa (siouxlandproud.com) Earlier in the week a turkey operation in Sac County was reported to be infected with Avian Influenza (H1N1): Highly Pathogenic Avian Influenza Detected in a Sac County Turkey Flock.
USDA currently has Colorado at 18 dairy herds; however, as of today that state site has 2 additional (20) infected herds listed: HPAI in Dairy Cattle | Department of Agriculture (colorado.gov). Minnesota also announced 2 infected turkey flocks and 1 dairy herd in the last week, totaling 7 ruminant H5N1 infections (6 dairy cattle and 1 goat herd). Idaho remains at 26 cases as of now (25 dairy and 1 alpaca). In good news, Michigan has not reported any new infections in dairy since June 11th and Texas since the 17th.
Case counts are improved in some places but remain concerning in others. In Iowa bulk milk testing is in place as part of circle testing surrounding poultry outbreaks, perhaps leading to accelerated case finding. Dr. Jeff Kaisand, Iowa State Veterinarian, speaking on an Iowa State University Extension Zoom call, stated that circle testing is limited to positive avian influenza outbreak sites; mandatory testing in Iowa does not extend to areas surrounding infected dairy herds.
According to an article posted bv Colorado Public Radio (More cows are getting avian flu in Colorado (cpr.org), all Colorado cases have been located in the large dairy and cattle-dense NE part of the state. 16 new cases have been reported in the last 14 days (HPAI in Dairy Cattle | Department of Agriculture (colorado.gov)), suggesting extremely rapid spread from herd to herd and/or a common source(s) of infection for multiple herds. This is not the type of case explosion that would be expected with random biosecurity lapses as the basis for disease spread. Genomic sequencing may be helpful in sorting out the relatedness of the isolates in this cluster.
I listened in to the Iowa State University Extension Virtual Chat 3 for Dairy and Poultry Producers and HPAI held last week online. The event was not recorded, due to the likelihood that information discussed is likely to quickly be out of date. However, a lot of good clinical impressions were shared by participants. A veterinarian on the webinar disclosed that bulk tank testing on an initially negative herd turned positive, with the herd displaying clinical signs approximately 5-7 days later. He also discussed good results with utilization of the H5 ELISA serology test for determining titers post-infection, despite the lack of USDA approval for its use for that purpose (An approved serology test would be invaluable in assessing both within herd and multi-herd prevalence of infection). Both he and another veterinarian with experience in dealing with affected herds described “red nose”-like lesions, conjunctivitis, and subcutaneous emphysema in some cattle, including non-lactating animals. Some herds have experienced somewhat higher mortality than has been otherwise described. There were also ill-defined trends toward decreased returns to estrus and increased late term abortions in affected animals. Most herds have not allowed follow-up PCR testing to determine longer-term virus status. Limited PCR testing of lagoon liquid has shown virus to be present, but viability/infectivity is unknown at this point.
In contrast to the wide-ranging discussion of the Iowa State webinar, CAST (Council for Agricultural Science and Technology) today held a highly scripted H5N1 in Dairy and Poultry Webinar, featuring a panel of experts. Much of the information, while highly relevant, is already available or known. One interesting piece of information provided by Mohamed El-Gazzar of Iowa State University described the increased success in stopping lateral spread of HPAI poultry outbreaks in 2022-2024 versus 2015, attributed to depopulation within 24 hours and disposal within 72 hours. In addition, pooling techniques are utilized in surveillance sampling to improve chances for earlier detection. These activities together shorten time of viral shedding by infected birds, lessening risk of direct or indirect spread to neighboring flocks. He suggested that the dairy industry should work towards earlier detection processes. Dr. Jamie Jonker of the National Milk Producers Federation stated that infected herd bulk milk PCR testing was going negative at 45-60 days post infection. Dr. Julie Gauthier of USDA-APHIS-VS cited results from the recent epidemiological studies suggesting that multiple biosecurity deficiencies existed in infected dairy herds and poultry flocks studied, suggesting possible factors for indirect transmission between herds.
It’s 90 days since the initial dairy herd outbreak diagnoses, and we still don’t know the basics! How are cattle infected? What is the infectious dose? Yes, we can infect them in the udder with low doses; that may cause some intra-herd spread via milking, but not between herds or to non-lactating animals. What is the incubation period? Shedding period? Do contact animals become infected? How? This is all basic stuff, and we don’t have open source answers. CDC published this graphic last week; USDA should be primarily responsible for answering the first 3 unknown routes:
BSL-3 research takes some time, but we should have some preliminary answers very soon, even if the results are not final. Please share any results you have, ARS!
Currently the USDA is putting all its chips on “biosecurity” and “milk / lactating cows” as the main risk factors in stopping spread. In my view, that doesn’t pass the smell test. For starters, it doesn’t explain poultry outbreaks. Commercial flocks have become really good at preventing biosecurity breaches, but suddenly, they allow dairy employees and vehicles to breach their protocols on 8 separate commercial operations?? I personally believe, as does the poultry industry, that allowing a virus to “hang around” large numbers of animals for long periods of time can only lead to area spread by aerosol or other “mysterious” means. Biosecurity breaches are undoubtedly a factor for spread to varying degrees, but preponderance of epidemiological evidence would at least suggest that some sort of area spread beyond people/fomites must be seriously investigated for dairy to dairy and dairy to poultry spread. The best way to prove or disprove that is to fully define oral and aerosol risk for infection through formal infection route and dose studies, not just infected herd test results.
In general USDA, some state animal health officials, and commodity groups seem to want to “manage” the release of all information related to this outbreak, and that will not work. Diagnostics are too ubiquitous, communications are too instantaneous (but scattered), and the consequences to multiple large industries are too costly to successfully “control” information outflow. And that is even before considering the zoonotic implications and all the players that brings into the arena.
Just as the depression and the dust bowl meant survival issues for struggling Nebraska farmers, H5N1 is imposing tough realities on multiple agricultural commodity groups. Respite in the cellar is temporary relief, but eventually we move forward to better times through courage to accept truth and change based on realities. My grandparents move to Illinois was a blessing to both my mother and my aunt; they met Norwegian farm boys at Iowa State resulting in me and all my cousins. Good things do come from desperate times!
John