Comparing US, Canada avian flu cases of ’22 and ’23

The United States and Canada had fewer commercial flocks affected in 2023, but for the final three months, 2023 outpaced 2022.

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If you look at things from strictly a numerical standpoint, you could say the highly pathogenic avian influenza (HPAI) outbreak in the United States and Canada was not as severe in 2023 as it was in 2022.

Mind you, at the time of this writing, there are still a few days left in 2023, it would almost be inconceivable that the number of commercial farms or birds in those flocks could surpass what was measured in 2022.

Obviously, the virus is still out there circulating among wild bird populations, so the significant reduction in HPAI cases in 2023 is largely attributable to the poultry industry and government and university partners for their dedication to good biosecurity and education about HPAI.

Having said that, we cannot spend too much time patting ourselves or each other on the back. We must maintain that vigilance to make sure that the number of infections continues to drop in 2024.

After reviewing the data from the past two years, I’d like to offer a few comparisons between those two years.

Avian influenza in the United States by the numbers

In 2022, 308 commercial flocks in the United States were affected by HPAI, involving roughly 57.6 million birds. Both of those numbers declined in 2023. As of the latest update provided by the United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) on December 27, 137 commercial flocks, involving approximately 19.7 million birds, have been affected.

During both years, the flocks included to obtain those totals represented the turkey, broiler, egg, duck and upland gamebird industries. Backyard flocks, wild birds or live markets were not included in these totals.

Avian influenza in the United States by location

When you look at where the cases occurred, six fewer states had confirmed cases of HPAI in commercial flocks in 2023 than in the previous year. Indiana, North Carolina, Colorado, Nebraska, Delaware, Kentucky, Texas, Washington, New York, Oklahoma and Idaho all had at least one flock infected in 2022 but none in 2023.

Conversely, Oregon, Virginia, Alabama, Illinois and Georgia all had commercial birds struck by HPAI in 2023 after evading the virus in 2022.

Minnesota and South Dakota were the two states with the most flocks affected in 2022 and 2023, although so far in 2023 they have flipped positions. Minnesota had 20 more flocks affected than South Dakota last year, but up to this point, South Dakota has had two more flocks affected.

The reduction in cases was largely noticed in Minnesota, which went from having 81 flocks hit by HPAI in 2022 to 33 in 2023. Also, Indiana, North Carolina and Colorado, which saw 10, 9 and 8 flocks affected in 2022, respectively, had no flocks infected in 2023.

The states that saw significant increases in 2023 were California, Kansas and Ohio. California saw an uptick from 15 flocks infected in 2022 to 19 so far in 2023. Kansas and Ohio both went from one flock in 2022 to five in 2023.

In terms of birds, Iowa had by far the most losses in 2022 at about 15.9 million, but that number dropped to about 2.9 million in 2023. The two states with the next most lost birds in 2022 – Nebraska and Colorado – have had no losses in 2023.

Ohio is the state that has lost the most birds in 2023, with that number coming in at nearly 4.6 million birds – an increase of about half of a million when compared with 2022. California also saw a jump in bird losses, going from about 707,000 to roughly 3.7 million.

Avian influenza in the United States by month

While HPAI cases typically drop substantially in the warmer months, there was never a month in 2022 where there weren’t at least some flock infections. In 2022, there were three cases in June, three in July and eight in August before things picked up in September, when there were 33 flocks affected.

However, in 2023, there were no commercial flock infections in the U.S. in those summer months.

It is concerning, however, that the number of infected flocks in the final months of 2023 have increased from 2022. For October, 23 flocks were affected in 2022 and 25 were affected in 2023. November saw 29 flocks hit in 2022 and 56 in 2023. There were 24 flocks affected by HPAI in December 2022, but 37 so far in December 2023.

Avian flu in Canada in 2022 and 2023

Canada also saw a meaningful drop in the number of HPAI infected commercial poultry flocks in 2023 when compared with the previous year.

In 2022, 190 flocks were lost to HPAI, while up to now in 2023, 103 flocks have been lost.

Most provinces have also saw a year-over-year decrease. Quebec is the exception with 27 affected flocks in 2023, but 15 in 2022.

Fewer provinces have also had flock infections. Nova Scotia had two flocks affected in 2022, but none in 2023. Manitoba came close, with only one farm hit in 2023, compared with 17 in 2022.

British Columbia had by far the most cases during both years, but the 56 commercial flocks lost up to this point in 2023 is still a meaningful decline from the 72 flocks lost in 2022.

Like was the case with the United States, Canada did not record a single month in 2022 without any HPAI infections in commercial poultry. In 2023, Canada only had one case in May, followed by three consecutive months with no positive HPAI detections, before three flocks were infected in September. October and December saw fewer cases of HPAI in 2023 when compared with 2022, but there was a strong surge of cases in November. The Canadian Food Inspection Agency (CFIA) reported 50 flock infections in November 2023, which was 12 more than were reported in November 2022.

More information to come

Since there are still a few days remaining in 2023, the figures referred to for the year are not complete.

Check back on for year-end totals for U.S. and Canadian flock losses by state and province, as well as year-end totals for bird losses by state in the United States.

To learn more about HPAI cases in commercial poultry flocks in the United States, Mexico and Canada, see an interactive map on   

View our continuing coverage of the global avian influenza situation

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