Friday, May 17, 2024

CDC Updated Influenza A in Wastewater Report

Week Ending 5/11/24


Earlier this week the CDC unveiled their Influenza A wastewater surveillance program, which receives reports from 674 facilities across the nation, although we've been seeing data from about 1/3rd of those stations over the first 3 weeks. 

This sudden interest in wastewater surveillance has been driven by the recent detection of avian H5N1 in American dairy cattle, and concerns there might be uncaptured spillovers into humans.

These surveillance reports only detect influenza A levels, and do not tell us what subtype, or the likely source.  

But this time of year, we would expect community flu levels to be declining.  

As you can see by the following comparison chart of the past 3 weeks, the number of stations reporting above average rates of influenza have increased week-over-week.  

This despite slightly fewer stations (n=218)  submitting data in this latest report.  

Much of this week's increase is centered in northern California, going from 2 to 5 sites. Again, it isn't clear what might be driving this increase. 

But we will definitely be watching this situation closely over the weeks ahead.