Summary of the Latest Week with Data
During the most recent week with data, viral signals in Columbia’s wastewater showed a mixed pattern compared to both long-term and seasonal averages. SARS-CoV-2 was detected at levels well below historical norms but higher than the recent 4-week average, indicating a modest uptick. Influenza viruses, including Influenza A and Influenza B, remained undetectable, consistent with both recent and seasonal lows. RSV-A and RSV-B were also absent. Enteroviruses and parechoviruses, particularly Enterovirus B, Enterovirus C, and Parechovirus A, were detected at levels above their long-term and seasonal averages, with some subtypes showing continued elevated activity. Parainfluenza 3 and various rhinoviruses were present at moderate levels. Notably, Enterovirus A71 was detected at a level near the assay’s limit of detection, suggesting low confidence in this signal. No new pathogens were detected that had been absent in the previous four weeks.
SARS-CoV-2
SARS-CoV-2 was detected at a low level, well below both long-term and seasonal averages, but higher than the recent 4-week average. This suggests a slight increase in wastewater signal, though overall activity remains subdued. Transmission occurs primarily via respiratory droplets and aerosols, with symptoms ranging from mild respiratory illness to severe pneumonia. Vaccines and boosters remain available and are the primary counter-measure for reducing risk and severity. Wastewater trends continue to be a valuable early indicator of community viral activity.
Influenza A
Influenza A (including H1N1, H3N2, and H5N1 subtypes) was not detected in the latest week with data, consistent with both the recent 4-week average and well below long-term and seasonal norms. Influenza A is typically transmitted via respiratory droplets, with symptoms including fever, cough, and body aches. Activity is usually highest in late fall and winter. Annual vaccination is the most effective preventive measure.
Influenza B
Influenza B was also undetectable, matching the recent 4-week trend and remaining below historical averages. Like Influenza A, it spreads via respiratory droplets and causes similar symptoms. Vaccination is available and recommended, especially for vulnerable populations.
RSV (Respiratory Syncytial Virus)
Both RSV-A and RSV-B were not detected in the latest week with data, consistent with recent and seasonal trends. RSV is a common cause of respiratory illness in infants and older adults, typically peaking in late fall and winter. Preventive monoclonal antibodies are available for high-risk infants, and a vaccine is now available for older adults.
Parainfluenza Viruses
Parainfluenza 3 was present at a moderate level, below long-term and seasonal averages but slightly above the recent 4-week mean. Other parainfluenza types were not detected. Parainfluenza viruses are spread via respiratory droplets and can cause croup, bronchitis, and pneumonia, especially in young children. No licensed vaccines are currently available.
Enteroviruses
Enterovirus B and Enterovirus C were detected at levels above both long-term and seasonal averages, though Enterovirus C showed a decrease compared to the recent 4-week average. Other Enterovirus A remained moderately elevated. Enterovirus A71 was detected at a level near the assay’s limit of detection, so confidence in this signal is low. Enteroviruses are transmitted via fecal-oral and respiratory routes, causing a range of illnesses from mild fever to severe neurological disease. No specific vaccines are available for most enteroviruses, except for poliovirus.
Parechoviruses
Parechovirus A and Parechovirus 1B were detected at levels above long-term and seasonal averages, though both showed a decrease compared to the recent 4-week average. Parechovirus 3 was present at a moderate level. Parechoviruses are spread primarily via fecal-oral transmission and can cause mild illness or, rarely, severe disease in infants. No vaccines are available.
Rhinoviruses
Rhinovirus signals were moderate, below long-term and seasonal averages but above the recent 4-week mean. Rhinovirus B was detected at a low but slightly increased level. Rhinoviruses are the most common cause of the common cold, spread via respiratory droplets and contaminated surfaces. No vaccines are available.
Other Respiratory Viruses
No significant signals were detected for metapneumovirus, influenza C, human bocavirus, or the seasonal coronaviruses (229E, HKU1, NL63, OC43). These viruses typically cause mild to moderate respiratory illness and are most active in colder months.
Summary and Implications
Wastewater surveillance for the most recent week with data indicates low but slightly increasing SARS-CoV-2 activity, while influenza and RSV remain at minimal levels. Enteroviruses and parechoviruses continue to circulate at elevated levels, with some subtypes showing persistent activity. Community members should remain attentive to respiratory and gastrointestinal symptoms, especially in young children and older adults. Staying up to date with recommended vaccinations, practicing good hand hygiene, and seeking medical advice for severe or unusual symptoms remain important steps to reduce risk. Wastewater data will continue to provide early signals of changes in viral activity.