This week’s national wastewater surveillance highlights an exceptional rise in picornavirus ampivirus, particularly in urban areas of Columbia, MO and Kansas City, MO, measured at over 13 times the usual baseline. This represents an unusual emergence for a virus that is typically undetectable, warranting close epidemiological attention and ongoing monitoring. Other notable increases include rotavirus C—with elevated levels at Chicago, IL, Boise, ID, and Kansas City, MO—and continued high signals of astrovirus (other) and rotavirus A at Columbia, MO, Chicago, IL, and Boise, ID.
Site-specific review reveals both high absolute viral levels and significant fold changes at urban sites. The largest relative change was observed for picornavirus ampivirus in Columbia, MO (224 RPB) and Kansas City, MO (1016 RPB), now present where it is almost never detected. Additionally, elevated detection of rotavirus C in Boise, ID (29,618 RPB) and Kansas City, MO is markedly above baseline, suggesting increased local circulation. Chicago, IL and Boise, ID also stand out for sustained high concentrations of norovirus genogroup II, astrovirus (other), and sapporo virus, though these appear stable compared to previous weeks.
Among priority respiratory and enteric pathogens, SARS-CoV-2 was detected at a moderate number of sites, notably Columbia, MO, Boise, ID, and Kansas City, MO, but without significant change in magnitude from recent observations. Influenza A and B signals remain sporadic and low, with only isolated detections in St. Louis, MO and moderate presence in Columbia, MO, Boise, ID, and Kansas City, MO. RSV-A and RSV-B detections are confined mainly to Boise, ID, Kansas City, MO, and Palo Alto, CA, all showing generally stable or slightly declining trends.
Detection of typically rare viruses is epidemiologically significant this week. The emergence of picornavirus ampivirus at multiple urban sites is noteworthy due to its usual absence from surveillance data. Additionally, the strong presence of coronavirus tegacovirus—an animal virus—at urban locations in Columbia, MO, Boise, ID, and Kansas City, MO, is unusual compared to rural expectations and may indicate unique exposures or cross-species transmission risks in city environments.
In light of continued and emerging enteric virus activity, residents in affected areas are advised to reinforce hygiene practices, including hand-washing and surface sanitation. Routine vaccination for influenza and COVID-19 remains critical, especially for at-risk populations. Healthcare providers should stay alert for atypical gastrointestinal presentations given the changing viral landscape.
Several sites report delayed data, impacting interpretation. Greater Boston, MA, Riverside, CA, and Ottumwa, IA are currently two weeks behind, while Milan, MO, Sacramento, CA, and Ontario, CA are one week behind. Surveillance teams will continue to prioritize timely updates and coverage to ensure rapid response to unusual viral activity at both urban and rural locations.