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:
- COVID-19 test positivity increased significantly, from 1.6% of COVID-19 tests returning positive results during the week ending July 11 to 2.2% positive during the week ending July 18.
- SARS-CoV-2 concentration in wastewater stayed consistent between July 11 and July 18, and the national wastewater viral activity level is “very low,” per the CDC.
- SARS-CoV-2 concentration in wastewater increased 13% between July 8 and July 15, and the national wastewater trend is “high” (upward trend and medium concentration) per WastewaterSCAN.
A summer COVID-19 wave continues to pick up momentum in the U.S. While disease levels remain on the lower end compared to past summers, almost all major metrics are showing increases across the country. Other public health threats, including cyclospora and measles, are also still on the rise.
WastewaterSCAN and Biobot Analytics both report growing SARS-CoV-2 in wastewater in their national averages and across most regions, as of mid-July. These increases are most clear-cut in the West and South — particularly at some WWSCAN testing sites in Alaska, Hawaii, California, Florida, and Louisiana — but all parts of the country have sites with recent high levels and notable increases. Some state dashboards, including Colorado’s and Washington’s, also report recent increases in SARS-CoV-2 levels.
The CDC still reports that SARS-CoV-2 levels in wastewater are “very low” nationally and across all regions, but this is likely in part because the CDC’s analysis only includes the last two years of data and does not incorporate periods when collective public health measures were in place. Also, when comparing CDC and WWSCAN data, it’s important to remember that WWSCAN determines its categories based on both magnitude and direction (not just magnitude).
Increasing COVID-19 spread is more evident in the CDC’s healthcare system data. The agency’s PCR test positivity network continues to report significant upticks in its national average and across several regions: the Southeast (health region 4), the Plains states (region 7), the Southwest (region 9), and the Northwest (region 10).
In addition, the CDC’s infectious disease forecasting center (which uses emergency department data for its modeling) estimates that COVID-19 cases are “growing or likely growing” in 37 states as of July 22, including states across all regions. Cases are not declining in any states, per the center.
In other preventable infectious disease news: the U.S. remains a measles hotspot this summer. The CDC has confirmed over 2,300 measles cases so far in 2026, surpassing the number of confirmed cases from all of 2025. And that’s only confirmed cases; the true number of infections “could be two or three times that actual number,” pediatrician and vaccine expert Paul Offit told The 19th. Like COVID-19, measles can lead to long-term health issues.
The parasite cyclospora also continues to spread, causing gastrointestinal symptoms for thousands of people. While health officials have linked the largest outbreak of this disease to lettuce from the distributor Taylor Farms, there are also many cases from other sources. Recent articles from the University of Minnesota’s Center for Infectious Disease Research and Policy and Johns Hopkins’ Bloomberg School of Public Health describe challenges with tracking this parasite and communicating about it to the public.
