PHiladelphia is bringing back its indoor mask mandate from April 18 after a 50% increase in Covid-19 cases over the past 10 days.
The reinstatement is the first among major US cities and comes just over a month after it was officially lifted. A few colleges have also reimposed indoor masking, including Columbia University and Barnard College in New York and George Washington University in Washington.
These measures come as cases in the United States have started to rise again, driven by the highly infectious BA.2 subvariant of omicron. Nationally, the seven-day rolling average of new cases was 28,169 on April 8, the highest since March 16, according to the US Centers for Disease Control and Prevention. Still, infections remain well below the peak of more than 800,000 reached in January as the omicron raged.
Philadelphia is reporting an average of 142 new cases per day, down from 94 on April 4. In New York, the average for daily reported cases is 1,861, down from 1,572 in early April.
According to the CDC, which provides county-level data through April 7, Philadelphia County is considered “low risk,” with a case rate of 55.9 per 100,000 people. By comparison, New York County, which encompasses New York’s Manhattan Island, is at “medium risk” with 238 cases per 100,000.
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The CDC does not recommend a mask mandate for either level of risk, although it does say people at high risk of severe Covid illness should consider wearing masks indoors in places at medium risk. The agency made changes to its recommendations earlier this year to focus on hospitalizations rather than the number of cases, although some public health experts have warned that positive cases are an early indicator of the increase in hospitalizations.
A lack of funding and recent policy decisions have made it harder for local governments to keep up with the spread of Covid. In some cities, testing centers have closed, while others have started charging for testing as government-subsidized programs end. People who use rapid tests to confirm a positive case rarely report their results, giving public health officials little information about the true extent of the virus.
Unlike other major cities, Philadelphia left the door open to reintroducing masking when it lifted its mandate. The city then said it would require masking again if cases rose more than 50% in 10 days, the average new cases per day was less than 225, and hospitalizations were less than 100.
The next level, which would require proof of vaccine in restaurants, would be reached when the average of new cases reaches between 225 and 500 and hospitalizations climb between 100 and 500.
Public health experts have praised governments that have communicated what it would take to require masking again, saying they recognize the virus is likely to fluctuate.
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