Overview: The U.S. Department of Agriculture (USDA), Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC), as well as state veterinary and public health officials, are continuing to investigate influenza A(H5N1). LINK

To date no similar illness, nor H5N1 detections, have been reported in Canadian dairy cattle.

H5 has also been detected in the U.S. in 44 people (LINK) including workers on dairy and poultry farms, in cats and wild birds on affected farms. Our understanding of H5N1 in North American mammals continues to grow. LINK

CDC calls for expanding HPAI testing of dairy workers after blood tests reveal more farm worker infections 7th Nov. 2024

Federal health officials on Thursday called for more testing of employees on farms with bird flu after a new study showed that some dairy workers had signs of infection, even when they didn’t report feeling sick. Farmworkers in close contact with infected animals should be tested and offered treatment even if they show no symptoms, said Dr. Nirav Shah, principal director of the U.S. Centers for Disease Control and Prevention. The new guidance comes after blood tests for 115 farmworkers in Michigan and Colorado showed that eight workers — or 7% — had antibodies that indicated previous infection with the virus known as Type A Influenza H5N1. “The purpose of these actions is to keep workers safe, to limit the transmission of H5 to humans and to reduce the possibility of the virus changing,” Shah told reporters. The CDC study provides the largest window to date into how the bird virus first detected in March in dairy cows may be spreading to people. It suggests that the virus has infected more humans than the 46 farmworkers identified in the U.S. as of Thursday. Nearly all were in contact with infected dairy cows or infected poultry.   LINK

4th November 2024. 160 confirmed new cases in 3 states in the last 30 days. 442 confirmed cases in total LINK.

2nd October 2024. 44 confirmed cases in the last 30 days in 2 states, Idaho and California. There are 244 confirmed cases in total. LINK The situation is evolving in California. LINK

9th September 2024. With 6 new cases reported over the past 30 days, the incidence rate of new HPAI cases in U.S. dairy herds seems to be slowing. Currently 197 infected herds have been reported, across 14 states, with California being the most recent new state to report detections. LINK

No HPAI cases have been reported in U.S. beef cattle, and no HPAI cases have been reported in Canadian dairy or beef cattle. LINK

26 August 2024. 20 confirmed cases of HPAI H5N1 in the last 30 days, with 5 states affected. LINK

13 August 2024. 2 herds, in Colorado and Idaho, with confirmed cases in dairy milking cows. LINK

12th July 2024. Influenza A detected in Oklahoma Dairy Cattle, with Oklahoma becoming the 13th U.S. state to report infected dairy herd.  LINK

9th July 2024. Influenza A detections in U.S. Dairy Cattle. 140 cases in 12 states. LINK

26th June 2024. Influenza A detections in U.S. dairy cattle. 129 cases in 12 states. LINK

13th June 2024. Influenza A detections in U.S. dairy cattle. 102 cases in 12 states. LINK

7th June 2024. Influenza A detection in Wyoming Dairy Herd. LINK

6th June, 2024. Influenza A detection in Minnesota Dairy Herd.  LINK

5th June, 2024. Influenza A detection in Iowa Dairy Herd. LINK

4 June 2024. Influenza A detections in U.S. Dairy Cattle. 80 cases in 9 states. LINK

24 May, 2024. Influenza A detections in U.S. Dairy Cattle. 63 cases in 9 states. LINK

26 April 2024. Most recent detection of 34th infected dairy herd, in Colorado, in addition to previously reported detections in Texas, Kansas, New Mexico, Idaho, Michigan, Ohio, North Carolina, and South Dakota. LINK

2 April, 2024 Influenza A detection in Idaho Dairy Cattle  LINK

1 April, 2024 Influenza A detection in New Mexico Dairy Cattle LINK

March 29, 2024 HPAI detection in Michigan dairy cattle LINK

HPAI detection in Idaho dairy cattle LINK 

March 25, 2024  HPAI detection in Texas and Kansas dairy cattle LINK

The clinical case presentation that has been reported is:

1. Sudden reduction in feed intake with decreased ruminations evident on physical exam and rumination monitors.

2. Sudden decrease in milk production on a herd level. Individual cows that are more severely affected have milk that is yellow and concentrated with the appearance of colostrum.

3. Variations in manure consistency with the most common finding being tacky to dry manure, although some cows appear to have diarrhea.

4. Secondary infections such as pneumonia and mastitis.

The affected cases appear to be in lactation 2 or greater animals that are more than 150 days in milk. Calves, heifers, and dry cows appear not to be affected. Morbidity is around 10% of the animals. Cases present over a 7-10 day time period and the first herds report a return to near normal production in 3 weeks.

These symptoms have been reported by the American Association of Bovine Practitioners and the USDA-APHIS.

3rd October 2024: The FDA, National Conference of Interstate Milk Shipments and USDA are developing a study on the prevalence of Highly Pathogenic Avian Influenza A(H5N1) in dairy cattle. A secondary objective is the identification of any viral transformations. States' participation will be voluntary. Sampling of raw milk from raw milk storage silos at dairy processing facilities will begin October 28th and run for 6 weeks. The study will be double-blinded: no traceback or trace forward will be possible. LINK

20th September 2024: CANADA: CFIA laboratories began testing raw milk arriving at a limited number of processing plants as of the week of August 19, 2024. 272 samples have tested negative. LINK  

9th September 2024: CANADA: As of Sept. 5, 2024, laboratories tested 1,211 retail milk samples from across Canada. All samples have tested negative for HPAI fragments, with no evidence of disease in dairy cattle detected in milk.

13 August 2024. Final results of the second round of testing U.S. retail milk and milk products: 167 samples were found to be negative for viable H5N1 virus. 29 samples were positive for H5N1 viral RNA (by qRT-PCR screening). Samples included aged raw milk cheese, pasteurized fluid milk, pasteurized cheeses, cream cheese, butter and ice cream. LINK

10 May 2024. Final results of the first round of testing U.S. retail milk samples: 297 samples from 17 states were negative for viable H5N1 virus. 60 samples were positive for H5N1 viral RNA (by qRT-PCR screening). LINK

1st May 2024. Update on FDA testing of U.S. retail milk: "The FDA is announcing an additional set of results from our national commercial milk sampling study underway in coordination with USDA. The study includes 297 total retail dairy samples. New preliminary results of egg inoculation tests on a second set of 201 quantitative polymerase chain reaction (qPCR)-positive retail dairy samples, including cottage cheese and sour cream, in addition to fluid milk, show that pasteurization is effective in inactivating HPAI. This additional preliminary testing did not detect any live, infectious virus." LINK

April 26 2024. Preliminary culture results from retail milk samples testing qPCR positive for Avian influenza H5N1. The FDA has received additional results from an initial limited set of geographically targeted samples as part of its national commercial milk sampling study underway in coordination with USDA. The FDA continues to analyze this information; however, preliminary results of egg inoculation tests on quantitative polymerase chain reaction (qPCR)-positive retail milk samples show that pasteurization is effective in inactivating HPAI.    LINK

April 25 2024. Initial results from FDA's nationally representative commercial milk sampling study. The agency continues to analyze this information; however, the initial results show about 1 in 5 of the retail samples tested are quantitative polymerase chain reaction (qPCR)-positive for HPAI viral fragments, with a greater proportion of positive results coming from milk in areas with infected herds. As previously noted and outlined in our summary below, qPCR-positive results do not necessarily represent actual virus that may be a risk to consumers. Additional testing is required to determine whether intact pathogen is still present and if it remains infectious, which would help inform a determination of whether there is any risk of illness associated with consuming the product. The FDA is further assessing any positive findings through egg inoculation tests, a gold-standard for determining if infectious virus is present. Early work by NIH-funded investigators indicates an absence of infectious virus in their studies of retail milk. To date, the retail milk studies have shown no results that would change our assessment that the commercial milk supply is safe. Epidemiological signals from our CDC partners continue to show no uptick of human cases of flu and no cases of H5N1, specifically, beyond the one known case related to direct contact with infected cattle. LINK

Highly pathogenic avian influenza (HPAI) in cattle: Guidance for private veterinarians. Updates include:

• The "affected dairy cattle are most commonly in the second lactation or greater and greater than 150 days in milk" was removed from the case definition for influenza A(H5N1) in dairy cattle. LINK
• CFIA advises against all Canadian cattle travelling to and participating in agricultural exhibitions in the U.S. at this time. LINK

HPAI in cattle: Guidance updates for private veterinarians. Updates include:  

Until further notice, CFIA will cover the fees for laboratory testing at any CAHSN laboratory that is approved to test samples in domestic animals. CFIA does not pay for associated veterinary fees for sample collection or shipment to the lab. 
All non-clinical dairy cattle will now be eligible for testing. A milk sample is required for lactating dairy cattle and a nasal swab is required for non-lactating dairy cattle. 
For suspect case submissions, the private veterinarian is required to report negative test results back to the district office upon receipt.

LINK

CFIA Highly pathogenic avian influenza (HPAI) in cattle: Guidance for private veterinarians. This document serves as a reference for private veterinarians to collect and submit samples for highly pathogenic avian influenza (HPAI) in dairy cattle, both for suspect and non-clinical animals. It also includes information on reporting requirements for suspect cases of HPAI in cattle.  LINK

Government of Canada letters:

• Letter for dairy cattle exporters: Canadian dairy cattle that travel to the US for a temporary stay (less than 60 days) must follow precautionary measures upon return to Canada. Lactating cattle must test negative for influenza A(H5N1) by PCR and have a negative result within 7 days of their expected return to Canada. There is an additional permit required. LINK
• Letter for beef cattle exporters: The regulations are for Canadian beef cattle that travel to the US for a temporary stay are similar to that of dairy cattle. There are differences in the requirements upon return to Canada for beef cattle: beef cattle must be isolated for 21 days, and there is no need for testing for influenza A(H5N1) between 14 and 21 days following re-entry.

HPAI Update from the Government of Canada: In addition to the robust protective measures that already exist, the Government of Canada, in collaboration with stakeholders, is expanding its surveillance to manage the possible emergence of HPAI in Canada by:

• requiring negative HPAI test results for lactating dairy cattle being imported from the United States to Canada.
• conducting enhanced testing of milk at the retail level to look for viral fragments of HPAI.
• facilitating the voluntary testing of cows that are not presenting with clinical signs of HPAI to facilitate enhanced industry biosecurity efforts.

LINK

Highly Pathogenic Avian Influenza (HPAI) in Livestock: LINK

30 Oct. 2024. USDA Announces Plan to Begin Bulk Testing Raw Milk for H5N1. LINK.

22 August 2024. CDC H5 Bird Flu national surveillance and targeted H5 surveillance. LINK

29 May 2024. Highly Pathogenic Avian Influenza (HPAI) H5N1 Personal Protective Equipment Recommendations. LINK

24 May 2024. USDA Expands Support for Producers to Stop the Spread of H5N1 in Dairy Cattle. LINK

10 May 2024 USDA HHS Announce New Actions to Reduce Impact and Spread of H5N1. LINK  

27 April 2024 Clarification Regarding Movement of Cattle Through Markets or Auctions to Slaughter, Under the April 24 Federal Order. LINK

26 April 2024  

APHIS Requirements and Recommendations for Highly Pathogenic Avian Influenza (HPAI) H5N1 Virus in Livestock For State Animal Health Officials, Accredited Veterinarians and Producers LINK     

Testing Guidance for Labs for Influenza A in Livestock LINK tps://www.aphis.usda.gov/sites/default/files/hpai-livestock-testing-recommendations.pdf   

Federal Order on Interstate Movement FAQs  LINK    

25 April 2024. Federal Order on Interstate Movement in U.S. Dairy Cattle LINK 

Canada

HPAI guidelines for fairs and exhibitions. Animal Health Canada, in collaboration with several provincial chief veterinary officers, the Canadian Food Inspection Agency (CFIA) and the Public Health Agency of Canada (PHAC), created a guidance document for exhibition organizers and biosecurity recommendations for before, during and after the exhibition to prevent the spread of HPAI H5N1 in dairy cattle. LINK

Dairy Farmers of Canada and Animal Health Canada: HPAI: Biosecurity Recommendations for Dairy Farmers LINK

Update on Guidance on biosecurity measures for farm visits (2nd note)

proAction: Canadian Dairy Quality Assurance Program Biosecurity Module LINK

Canadian Food Inspection Agency Biosecurity for Canadian Dairy Farms: National Standard LINK

U.S.

Dairy Biosecurity Recommendations – HPAI and More_AABP LINK  

USDA-APHIS Secure Milk Supply (SMS) Dairy Biosecurity Resources LINK

Canadian Food Inspection Agency: Highly pathogenic avian influenza (HPAI) in livestock LINK

USDA-APHIS: Detection of Highly Pathogenic Avian Influenza in Dairy Herds: Frequently Asked Questions LINK

USDA-APHIS: Questions and Answers Regarding Milk Safety During Highly Pathogenic Avian Influenza (HPAI) Outbreaks   LINK