Rising COVID-19 Test Positivity Signals Summer Surge Continues

WASHINGTON, Aug. 27 - New data released today show that COVID-19 tests are returning positive at higher rates nationwide and in several hard-hit regions, underscoring the persistence of a late-summer surge driven by the XFG “Stratus” subvariant.

The Centers for Disease Control and Prevention reported a national test positivity rate of 9 percent for the week ending August 20, up from 7.6 percent the previous week, marking a 1.4 percentage-point increase and the highest level since last summer. Hospitalizations are also climbing, with the weekly rate reaching 3.7 admissions per 100,000 people, the steepest rise among seniors and children under five.

In California, where testing and hospital-use data often foreshadow national trends, the Department of Public Health announced that 11.59 percent of coronavirus tests returned positive for the week ending August 16, nearly double the 5.69 percent positivity recorded in mid-July and matching summer peaks from 2023. Emergency departments statewide have seen a 300 percent increase in COVID-related visits since early July, prompting renewed calls for vigilant testing and isolation practices.

Public health officials reiterated that at-home antigen tests remain effective at detecting current variants, as these kits target conserved viral proteins and retain high sensitivity for active infections. The CDC continues to advise anyone with symptoms or known exposures to test immediately and to isolate pending results, while individuals at high risk or living with vulnerable people should consider retesting 24-48 hours after an initial negative result.

As colder weather approaches and schools reopen, experts warn that COVID-19 activity may intensify. They recommend maintaining adequate supplies of rapid tests, staying up to date on vaccinations, and following local health guidance to mitigate spread in the coming months.