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 33% between July 22 and July 29, and the national wastewater trend is “high” (medium concentration and upward trend), per WastewaterSCAN.
- SARS-CoV-2 concentration in wastewater increased 37% between July 25 and August 1, and the national wastewater viral activity level is “very low,” per the CDC.
- COVID-19 test positivity increased significantly, from 2.5% of COVID-19 tests returning positive results during the week ending July 25 to 3.1% positive during the week ending August 1.
A summer COVID-19 wave is still rising in the U.S., according to data through late July. Increases in disease spread are most pronounced in the South and West, but all regions have growing outbreaks. This summer’s wave started later and lower than similar waves in prior years, making it difficult to anticipate what might happen in the coming months.
WastewaterSCAN and Biobot Analytics both report increasing SARS-CoV-2 in their national and regional averages throughout July. WWSCAN now reports a “high” national trend for SARS-CoV-2 (with increasing levels and medium concentration compared to historical data) along with a “high” trend in the West and South, and “medium” in the Midwest and Northeast.
After months of a stable and “very low” average, the CDC is finally reporting a pronounced increase in its national wastewater viral activity level for SARS-CoV-2. Even though health experts generally consider wastewater data to be an early indicator for changing COVID-19 trends, the CDC’s analysis methods — using a higher baseline for historical comparison than other wastewater data providers — often leads their dashboard to be delayed in warning about a starting wave.
The West and South are getting hit harder by this wave so far; for example, California’s wastewater dashboard reports an intense increase in state SARS-CoV-2 levels across June and July. But there are hot spots across the country at wastewater testing sites in New York, New Jersey, Indiana, Ohio, and Rhode Island — among other states.
Test positivity, as measured by the CDC’s PCR testing network, also keeps increasing. This week, the national average went above 3% for the first time since March. And test positivity is increasing across different regions: New England (health region 1), the mid-Atlantic (region 3), the Southeast (region 4), Great Lakes states (region 5), Central South states (region 6), and the Southwest (region 9).
The CDC’s infectious disease forecasting center reports clear increases across the country, too. In its modeled estimates from emergency department data, the center reports that COVID-19 cases are “growing” in 41 states and “likely growing” in two more states, as of August 5.
In other disease news: outbreaks may be starting to slow down for cyclospora, the parasite causing severe gastrointestinal illness. The health department in Michigan, at the center of the largest outbreak, announced on Friday that reports of new cyclosporiasis cases are decelerating and notes that most exposures to the parasite likely happened in late June through early July.
Still, there are several active outbreaks of cyclospora across many states. In a recent article in The Conversation, wastewater researcher Joan Rose describes how the parasite may spread when contaminated sewage is used to water crops. Rose calls for expanding wastewater surveillance to include protozoan diseases like cyclospora, along with other pathogens that may thrive in sewage.
