This week’s national wastewater viral surveillance highlights significant and atypical elevations in Pneumovirus RSV-A and Parainfluenza 1, both registering over threefold increases above recent 8-week baselines. Notably, RSV-A has spiked dramatically at Boise, ID and Monett, MO, raising concern given the normally lower baseline outside late fall peaks. Parainfluenza 1 is also showing a pronounced rise, especially in Columbia, MO (urban), Boise, ID, and Monett, MO (rural), suggesting an unseasonably robust community spread.
Several additional site-specific alerts warrant attention. Astrovirus avian nephritis virus showed a more than threefold rise at Monett, MO, consistent with its rural/agricultural context but notable due to the sharp change from baseline, which could indicate changing animal or zoonotic transmission dynamics. Additionally, multiple urban sites—Columbia, MO, Chicago, IL, and Riverside, CA—are experiencing persistently high levels of astrovirus (other), norovirus genogroup I and II, rhinovirus, and enteroviruses. While these enteric viruses frequently dominate winter wastewater profiles, current levels remain at the high end of seasonal expectation and should continue to be monitored for further escalation.
SARS-CoV-2 remains detectable at multiple sites, including Columbia, MO, Chicago, IL, and Riverside, CA, with viral loads generally stable to slightly elevated compared to recent weeks. Influenza A (both total and H3N2 subtypes) persists at moderate levels at five surveillance points, but without significant increases relative to last month. Influenza B virus also remains present at low levels in Chicago, IL and Monett, MO, without distinct upward momentum. Pneumovirus RSV-A is the clear outlier this period with marked relative increases, whereas RSV-B shows only minor activity. These findings suggest continued co-circulation of multiple respiratory viruses, with RSV-A now leading as the most notable emergent risk.
It is also important to highlight detection of typically rare or low-prevalence viruses this week. Picornavirus kobuvirus cebes (porcine) reached high levels at Columbia, MO—an urban setting where this animal-origin virus is less expected outside agricultural interfaces—indicating possible environmental or food-chain-linked introduction. Astrovirus avian nephritis virus was also newly detected at higher levels in Monett, MO with over a 3-fold increase, and Enterovirus G (pig) was detected at atypically high levels in Columbia, MO and Riverside, CA, both urban locations. These patterns demand further source investigation, particularly for potential cross-species or environmental transmission routes.
With multiple respiratory and enteric viruses circulating at elevated or increasing levels, the public is reminded of the importance of seasonal vaccinations (especially for influenza and COVID-19 where indicated), good hand hygiene, and prompt isolation when symptomatic. Special vigilance is needed in settings with vulnerable populations, such as child care facilities and elder care homes, given the concurrent spread of RSV and enteric viruses.
Finally, please note that several monitored locations—Milan, MO, Palo Alto, CA, and Ontario, CA—have data lagging by up to three weeks, and recent changes may be under-reported from Kansas City, MO, Greater Boston, MA, Ottumwa, IA, and Sacramento, CA. Interpret local trends at these sites with caution pending upcoming data updates.