Here are the latest national COVID-19 trends, according to the U.S. Centers for Disease Control and Prevention (CDC) and major wastewater surveillance providers:
- SARS-CoV-2 concentration in wastewater increased 4% between September 23 and September 30, and the national wastewater trend is “high” (high concentration and downward trend), per WastewaterSCAN.
- SARS-CoV-2 concentration in wastewater increased 7% between September 26 and October 3, and the national wastewater viral activity level is “low,” per the CDC.
- COVID-19 test positivity decreased 17%, from 4.9% of COVID-19 tests returning positive results during the week ending September 26 to 4.1% positive during the week ending October 3.
This summer’s COVID-19 wave is pushing into the fall. Data through early October show disease levels are still highest in the West, while they are increasing in parts of the Northeast and Midwest. Flu season is also getting underway earlier than usual.
The West continues to report the highest COVID-19 levels of any region, according to wastewater and test positivity data from the CDC as well as Biobot Analytics’ wastewater trends. The wastewater data report increasing disease spread through early October for this region, while testing and emergency department (ED) data report declines (in both the Northwest and Southwest); these disagreements will likely be resolved in future data updates.
In the South, COVID-19 trends are still coming down from the high levels we saw this summer. Like in the West, there is some disagreement between data sources here, with the CDC reporting an increase in its regional wastewater viral activity level for the South but decreases in test positivity and ED visits. This wastewater trend is driven by Florida, where the CDC reports a “very high” wastewater viral activity level for the week ending October 3. Florida could be a revived hotspot, or the high levels at a couple of sewage testing sites could be from other factors interfering with testing like environmental changes.
Parts of the Northeast are reporting higher and/or increasing SARS-CoV-2 levels in wastewater, including New York, Massachusetts, and Connecticut. But these are preliminary data, and healthcare system metrics (test positivity and ED visits) again conflict, reporting possible plateaus or even declines for COVID-19 spread in this region. The type of sustained increase in infections that I expect to see with winter in the Northeast doesn’t seem to have fully started yet.
One reason for discrepancies in wastewater surveillance data could be the gap in reporting for about 200 testing sites covered by the CDC’s contract with biotech company Verily. As I noted last week, the CDC awarded Verily a new contract on September 28 after its prior one concluded on September 14, meaning the sites covered went at least two weeks without data collection. In Maine, for example, sites covered by the Verily contract have not reported new data since mid-September.
Similarly in the Midwest, some states are reporting increased COVID-19 spread, though levels overall remain lower than other regions. The CDC’s infectious disease forecasting center estimates that COVID-19 cases are “growing or likely growing” in 12 states as of October 7, including mostly Midwest and some Mountain West states, plus Maine, Rhode Island, and Alaska. The center estimates that cases are “declining or likely declining” in 14 states and “not changing” in 25 states.
Meanwhile, flu spread is getting underway earlier than usual this year, especially on the West coast. National metrics are still well below the threshold for officially entering flu season, but the CDC’s disease forecasting center estimates that flu cases are “growing or likely growing” in 49 states plus Washington D.C., and only “not changing” in Hawaii. In Southwest states (health region 9), nearly 10% of flu PCR tests were positive for the week ending October 3, a high level that we typically don’t see until late November or December.
