According to the Centers for Disease Control and Prevention (CDC), over half of the states in the United States are now experiencing "high" or "very high" levels of the SARS-CoV-2 virus, which causes COVID-19, in their wastewater. The recent figures indicate that the current wave of COVID-19 is spreading across a growing number of states this summer.

The nationwide assessment by the CDC marks the first time since winter that the overall level of SARS-CoV-2 in wastewater has reached a "high" level. Western states continue to exhibit high levels, which had initially worsened last month. Other regions are now also seeing steeper increases, approaching or surpassing "high" levels.

The CDC's update had been delayed due to the Independence Day holiday in July. The rise in COVID-19 cases aligns with an increase in patients seeking emergency room care. The District of Columbia and 26 states are witnessing "substantial increases" in COVID-19 emergency room visits, highlighting the escalating impact of the current wave.

Nationwide, the average proportion of emergency room patients with COVID-19 is now at its highest since February, demonstrating a 115% increase from a month ago. While some states continue to maintain low levels of emergency room visits and hospitalizations, resembling levels seen during earlier stages of the pandemic, others have transitioned to "moderate" levels. Hawaii, for instance, experienced a surge surpassing the previous two waves, while Florida is currently at peak levels not seen since winter.

Aron Hall, the deputy director for science in the CDC's Coronavirus and Other Respiratory Viruses Division, noted that the recent increase is consistent with past summer waves, emphasizing the importance of vaccination and additional precautions for at-risk individuals with underlying health conditions.

The first states to reach "high" levels of COVID-19 in wastewater predominantly occupied the Western region, where an acceleration in COVID-19 patient admissions in emergency rooms and reported infections in nursing homes has been observed.

Similar to other countries, including the United Kingdom, which has seen COVID-19 hospitalizations rise to levels not seen since February, there are indications that the summer wave may have peaked in certain states where the virus initially gained momentum.

CDC forecasts released this week suggest that COVID-19 infections are growing in almost all states, with three states - Hawaii, Oregon, and New Mexico - exhibiting "stable or uncertain" trends.

Hall cautioned that while COVID-19 trends have historically slowed after summer peaks, they remain at significantly higher levels than during previous springtime lulls, highlighting the continued vulnerability of individuals.

The CDC's most recent variant projections indicate that the KP.3 variant now accounts for over a third of infections nationwide. Following are the KP.2 and LB.1 variants, both descended from the JN.1 strain dominant during the winter. Collectively, these three variants represent more than 75% of infections across the country. However, the CDC has not identified increased severity of illness associated with these variants.

Hall emphasized that the CDC continuously monitors hospital data, ongoing studies, and genetic analyses of the virus for any signs of heightened risk from new variants. He stated that no data sources have indicated that these variants cause more severe disease than previously observed.

As of June, the CDC estimated that all regions in the country were experiencing a mix of these strains, with varying prevalence depending on the location. The KP.3 variant is more widespread in multiple regions, LB.1 has a larger presence in the New York and New Jersey area, and KP.2 is predominant in New England.

Hall concluded by stating that while the growth of KP.3 and LB.1 variants is notable, it is considerably lower than that of highly mutated strains like the original Omicron variant.

In light of these developments, health authorities are urging individuals, particularly those at higher risk, to take extra precautions and adhere to safety measures such as vaccination, masking, and testing to mitigate the spread of COVID-19.

Overall, the nationwide increase in COVID-19 levels detected in wastewater testing underscores the importance of continued vigilance and adherence to public health measures in the ongoing battle against the virus.