July 3, 2024 – COVID-19 cases have been on the rise nationwide this summer, and now wastewater monitoring data suggests a further increase may be underway in the Western part of the U.S.
The CDC has updated its wastewater monitoring website to report that the virus that causes COVID, called SARS-CoV-2, is being detected at high levels in some Western states. The Western reporting region includes 13 states and one territory: Alaska, Arizona, California, Colorado, Guam, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.
The new report of increased COVID activity comes as the busy Fourth of July holiday travel period gets underway. Wearing a well-fitting mask in crowded indoor places remains on the CDC’s COVID prevention tip sheet, in addition to staying up to date on vaccinations and practicing good hygiene.
Wastewater virus detection is considered a bellwether for some infectious diseases because it can indicate person-to-person viral spread before testing trends, since people who are sick tend to wait to go to the doctor or hospital. Also, wastewater monitoring can show trends when people are infected with a virus and do not have symptoms. COVID symptoms typically appear between 2 and 14 days after exposure.
In its latest wastewater monitoring report, the CDC urged people to put the upward trend into the context that COVID activity remains historically low.
“During April and May 2024, COVID-19 activity was lower than at any time since the start of the pandemic. Recent increases need to be considered from that baseline. This includes increases in COVID-19 test positivity and emergency department visits, suggesting growth in COVID-19 activity across several states, and increases in rates of COVID-19-associated hospitalizations among adults 65+ at some Western sites,” the agency explained its latest update. “While there are indications for the potential start of a summer surge, nationally COVID-19 activity remains low. CDC will continue to monitor to see if these recent increases persist.”
The CDC wastewater monitoring program includes data from 1,214 sites and is estimated to cover about 126 million people, or 37% of the U.S. population.
The latest numbers indicate a concerning departure from the SARS-CoV-2 activity level that has been trending upward steadily since May. The new data from Western states jumped more steeply than the rest of the nation during the week spanning June 15 to June 22.
Monitoring by Stanford and Emory University scientists posted on the website WastewaterSCAN.org also shows higher levels of SARS-CoV-2 throughout the country. The donation-funded program reports on municipal wastewater from nearly 200 sites nationwide, and it said virus activity was “high” during the past 3 weeks for the entire country, except the Northeast, where activity was labeled “medium.”
