As more than a dozen states are now seeing a surge in coronavirus cases, local health officials are closely monitoring the situation in the Philadelphia area.
Pennsylvania, New Jersey and Delaware are all concerned about an uptick in cases or the positivity rates.
So health officials are urging everyone to do their part to limit the spread of the virus.
They don't want the surges seen across the South, West and Mid-West, where some hospitals in Texas and Arizona are nearing capacity.
Experts say the eruption of cases in areas thought to be under control shows how dangerous the virus can be.
"This virus is what I call a leaky bucket; if there's one small micro leak, it'll get out and it's going to keep transmitting," says Michael Osterholm, Ph.D., an infectious disease researcher and flu expert from the University of Minnesota.
Dr. Osterholm's projections have become important for planning by public health departments around the country.
Local lawmakers are concerned about that "leaky bucket" aspect to coronavirus, and they are keeping close tabs.
In Delaware, Governor John Carney is delaying the next phase of reopening.
Cases there and in Pennsylvania are slightly climbing.
In New Jersey, the positivity rate, the percentage of people testing positive, worries Governor Phil Murphy.
It went up slightly this week to 2.1 percent.
Delaware is 3.3 percent.
Pennsylvania is at 4.3 percent.
Pennsylvania has another issue. The testing rate remains in the 55 to 58% range, well behind other states, including New Jersey and Delaware, who exceed their testing goals.
Other states are also troubled by much higher positivity rates.
In Florida, Thursday's positive rate is 9.6%.
While that's high, it marks a big drop from Wednesday's 20% rate.
The majority of new cases are young adults, who may not become seriously ill, but can easily spread the virus to more vulnerable adults in their lives.
Federal health officials want them to adhere to social distancing, face coverings, and good hand-washing to help slow the spread of the virus.
"The chances are if you get infected, you're going to infect someone else," says Dr. Anthony Fauci of the White House Coronavirus Task Force.
"Ultimately you infect someone who's vulnerable," he continues.
"We can be either part of the solution or part of the problem," he adds.
He says it's especially important for younger adults at high risk for complications or close to someone at high risk, which means almost everyone.
COVID-19 test positives creep upward in Philadelphia area