COVID-19 Wastewater Viral Activity Update

The U.S. Centers for Disease Control and Prevention (CDC) has classified wastewater viral activity levels, with the latest reports showing a shift from “very high” to “high” across many states. As of October 12, 2024, only eight states still exhibit “high” levels, while the majority fall into “moderate” or “low” categories. Despite a general decline in positive COVID-19 test rates—now at 6.3%—the presence of new subvariants, particularly the KP.3.1.1, continues to drive infection rates. These subvariants, labeled FLiRT due to their mutations, have shown increased transmissibility but are associated with milder symptoms, suggesting that while the virus remains prevalent, the severity of cases may not be as high as in previous waves.

Current Wastewater Monitoring Findings

• High Viral Activity: As of October 12, eight states are still reporting “high” levels of viral activity, while 13 states have “moderate” levels, and 18 states show “low” levels.
• Overall Trends: The national percentage of positive COVID-19 tests has decreased from previous weeks, indicating a downward trend in infections.

Impact of Subvariants

Recent surges in COVID-19 cases have been linked to the emergence of new subvariants, particularly the FLiRT variants, which have mutations that allow them to evade immune responses more effectively. Despite this, existing vaccines still provide some protection against severe illness and long COVID. The dominance of the KP.3.1.1 subvariant, which accounted for over 57% of cases in early October, highlights the ongoing evolution of the virus.

Public Health Recommendations

Given the ongoing presence of COVID-19, particularly in certain states, public health officials emphasize the importance of self-isolation for individuals who test positive. More vulnerable populations are still at risk for severe illness, necessitating continued vigilance and adherence to public health guidelines.