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:
- About 1.8 in every 100,000 people were hospitalized for COVID-19 during the week ending March 8.
- COVID-19 test positivity has decreased 8%, from 3.7% of COVID-19 tests returning positive results during the week ending March 8 to 3.4% of tests during the week ending March 15.
- SARS-CoV-2 concentration in wastewater has increased 1% between the week ending March 8 and the week ending March 15, and the national wastewater viral activity level is “moderate,” per the CDC.
- SARS-CoV-2 concentration in wastewater has increased 8% between March 5 and March 12, and the national wastewater trend is “high,” per WastewaterSCAN.
- Healthcare visits for influenza-like illness have decreased 10% between the week ending March 8 and the week ending March 15.
COVID-19 levels in the U.S. have remained at about the same, moderate level for the last couple of weeks. In the most recent data, some sources report slight increases, while others report slight decreases. It seems unlikely that disease spread will get much lower this spring before going up again, renewed by further travel, gatherings, and viral variants.
The major wastewater data providers offer mixed signals this week: the CDC reports a very slight increase (1%) in its national average from March 8 to March 15, while WastewaterSCAN reports a greater increase (8%) from March 5 to March 12, and Biobot Analytics reports a decrease (exact number not provided) from March 8 to March 15. Despite the differences, all three sources support that there is a lot of SARS-CoV-2 going around right now, and levels have not changed much in the last month.
At the regional level, the South and Midwest continue to report more SARS-CoV-2 in sewage than the Northeast and West. The South, in particular, stands out as a region with higher and potentially increasing viral levels across all three wastewater data sources. WWSCAN also reports an increase in the Northeast in early March; I’ll be watching to see if any other data sources back up this trend.
The CDC’s disease forecasting center estimates that COVID-19 cases are “likely growing” in only four states, as of March 18: Washington, Oklahoma, New York, and Maryland. Cases are “declining or likely declining” in 25 states and “not changing” in 18 states, the center estimates. Like the wastewater levels, national trends in emergency department visits and hospitalizations have hovered at similar rates for the last couple of weeks.
As I noted last week, COVID-19 levels right now are much higher than we normally see at this time of year. That’s partially due to a lower-than-usual winter surge, but it’s also thanks to human behavior: the coronavirus continues to spread wherever people gather in close quarters. Without collective health measures, the “baseline” between COVID-19 waves continues to get higher.
In other disease news: flu rates continue to drop, though we are still a couple of weeks away from the end of this year’s flu season. Bird flu also remains a threat; the CDC recently reported more details from its investigations into two human cases from earlier this year. Measles cases continue, too — more than 400 cases have been reported across 19 states, and the U.S. may “lose its measles elimination status,” Dr. Katelyn Jetelina wrote in the Your Local Epidemiologist newsletter yesterday.
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[…] late March. These sources are back in alignment after WWSCAN and the CDC reported slight increases last week. All three indicate that viral levels have stayed fairly consistent in recent weeks; WWSCAN, for […]