US flu markers continue steady rise
US flu markers rose again last week, though reporting may be impacted by holiday-related delays, the US Centers for Disease Control and Prevention (CDC) said today in its weekly update, which covers the week ending Dec 25.
The eastern and central parts of the country are reporting the bulk of the infections, which have been dominated by H3N2. After mainly affecting younger age groups earlier in the season, illnesses are now being reported across a wider range. The CDC has also noted that other respiratory viruses are circulating, which could influence influenza-like illness (ILI) surveillance.
Overall, the percentage of clinic visits for ILI rose to 3.8%, up from 3.1% the previous week. At clinical labs, 6.2% of respiratory specimens tested positive for flu, up from 5.6% the week before.
Nineteen states are reporting very high or high flu activity, an ILI clinic visit marker, which is up sharply from eight reported the week before.
No new pediatric flu deaths were reported, keeping the season's total at two. For hospitalizations, the cumulative rate at sites the CDC and its partners track is 1.8 per 100,000 population, more than double the flu hospitalization rate seen during the 2020-2021 season.
Jan 3 CDC FluView update
Eurasian H5N1 detection in Canadian birds prompts warnings
Following a highly pathogenic H5N1 avian influenza outbreak at an exhibition farm in Newfoundland and Labrador, officials announced H5N1 detection in wild birds near St. John's, the CBC reported, citing government wildlife sources.
The arrival of the H5N1 virus in Canada has prompted warnings of a threat to birds in other Americas countries.
OFFLU, the animal influenza expert network from the World Organisation for Animal Health and the United Nations Food and Agriculture Organization, in a Dec 29 statement said the recent detection in Canada marks the first identification of the highly pathogenic (goose/Guangdong/1/96-lineage) H5 virus in the Americas since 2015. It said confirmation of the Eurasian strain is a cause for concern for wild birds, zoos, and poultry operations in the Americas, and it noted that some East Coast states in the United States are home to very large poultry operations.
The US Geological Survey (USGS) said in a recent wildlife update that recent wildlife sampling of nearly 6,000 samples turned up no high path avian influenza viruses, but it said the detection of H5N1 in Canada warrants increased vigilance in the United States.
Dec 27 CIDRAP News scan
Dec 29 OFFLU statement
Dec 29 USGS wildlife bulletin