(CNN) - Although the new coronavirus has been spreading through the United States for months, and there are cities seeing a flattening of the curve, some areas of the country have recently begun to find an uptick of cases.
Some of these hot spots are in states that have just begun allowing businesses to reopen.
In Georgia, Gov. Brian Kemp said the state will open a temporary medical pod in cities such as Gainesville, about an hour northeast of Atlanta.
Gainesville is "being stressed pretty hard ... at the moment," Kemp said Tuesday. The governor mentioned last week that while some areas of the state have seen reduced cases, Gainesville has an increase and area hospitals have had more hospitalizations.
The high number of daily hospitalizations for Covid-19 has continued this week.
Gainesville, with about 40,000 residents, is the county seat of Hall County, home to several poultry plants.
Kemp was in Albany on Tuesday, where another of the mobile units with about 20 beds was opening for non-Covid-19 patients. Speaking about the Gainesville pod, he said they'll set it up but hope it's not needed.
"But it's going to be there in case we do. And that'll be a good regional spot, you know if something happens in Athens or anywhere across northeast Georgia, north Georgia," the governor said.
Another unit will be set up in Rome, Georgia, the governor said.
According to data from Johns Hopkins University, 19 states are seeing an upward trend in new confirmed coronavirus cases over the past 14 days. The number of new cases appears to be going down in 13 states, and 18 states appear to be at about the same levels.
Some states may see their counts rise because they are confirming more cases through better testing or because new infections are increasing.
It's still too early to determine whether reopening actions have resulted in more cases and deaths, and it may take several weeks for the effects to become apparent.
Georgia began allowing some nonessential businesses such as gyms, barber shops, hair salons, tattoo parlors and bowling alleys, to reopen April 24 with restrictions on physical distancing.
A CNN analysis shows that Georgia has had a relatively consistent number of daily new cases since April 24. In this period, the seven-day average of the number of new cases per day has only been as low as 628 and as high 769, and the overall trend remains relatively steady.
Track the virus in each state and across the US
Lawsuit: Federal prisoner sprayed with disinfectant
Prison officials sprayed disinfectant on an inmate who collapsed and spit up blood at a federal prison in New Jersey on April 20, according to a lawsuit filed Monday by the ACLU of New Jersey and attorneys representing four "medically vulnerable" inmates at the correctional facility.
The inmates filed a class action lawsuit against warden David Ortiz and Michael Carvajal, director of the Bureau of Prisons, seeking temporary release for themselves and others who are medically vulnerable at the Fort Dix Federal Correctional Institution.
A spokesman for the Bureau of Prisons declined to comment, citing pending litigation.
At least 4,893 incarcerated or detained people have contracted Covid-19, and at least 88 have died, according to a report released Wednesday by the US Centers for Disease Control and Prevention.
The CDC report puts the number of staff members who have tested positive at 2,778, with 15 deaths.
The findings are based on data from 37 state and territorial health departments. The CDC reached out to 54 jurisdictions, but about 30% didn't provide requested information on jails and prisons.
Still, the CDC found that 420 correctional or detention facilities across the United States have reported infections -- resulting in at least 491 coronavirus-related hospitalizations among detainees and 79 hospitalizations among staff. Researchers looked at cases reported through April 21.
"Approximately one half of facilities with Covid-19 cases reported them among staff members but not among incarcerated persons," the report said. "Because staff members move between correctional facilities and their communities daily, they might be an important source of virus introduction into facilities."
Differences in testing between states also could have influenced the number of reported cases, researchers said.
Your top coronavirus questions, answered
No states that is reopening has met White House guidelines, researcher says
While more states lift stay-at-home restrictions, none have met all of the White House's guidelines on when they can safely start to reopen, a researcher from the Johns Hopkins Center for Health Security said.
"To my knowledge, there are no states that meet all four of those criteria," said Caitlin Rivers, a senior scholar at Johns Hopkins.
She described the four criteria at a House Appropriations Subcommittee on Wednesday:
"The first is to see the number of new cases decline for at least two weeks, and some states have met that criteria. But there are three other criteria and we suggest they should all be met," Rivers said.
Those include having "enough public health capacity to conduct contact tracing on all new cases, enough diagnostic testing to test everybody with Covid-like symptoms" and "enough health care system capacity to treat everyone safely."
It will take weeks to learn how many new cases and deaths emerge after states start easing restrictions.
But the US still hasn't done enough to protect residents from the coronavirus pandemic, said Dr. Richard Besser, former acting director of the Centers for Disease Control and Prevention.
The US must overcome major obstacles to help prevent a resurgence of coronavirus, he said. As of Wednesday, more than 1.2 million people in the US have been infected, and more than 73,000 have died, according to data from Johns Hopkins University.
"We don't have the testing capacity now to know where this disease is," Besser said.
"We have not scaled up the thousands and thousands of contact tracers that we need, we don't provide safe places for people to isolate or quarantine if they are identified as either having an infection or being in contact
Here's where all 50 states stand on reopening
'Wake up, world. Do not believe the rhetoric'
Researchers are discovering new information about how early and how rampantly this coronavirus has been spreading.
A new genetic analysis of the virus taken from more than 7,600 patients around the world shows it has been circulating in people since late last year, and must have spread extremely quickly after the first infection.
"The virus is changing, but this in itself does not mean it's getting worse," genetics researcher Francois Balloux of the University College London Genetics Institute told CNN.
At most, 10% of the global population has been exposed to the virus, Balloux estimated.
Such a low percentage means the fight against coronavirus is far from over, said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.
He estimates the novel coronavirus has infected between 5% to 15% of the population and will continue to spread until about 60% to 70% are infected.
"Think how much pain, suffering, death and economic disruption we've had in getting from 5% to 15% of the population infected and hopefully protected," Osterholm said.
"Wake up, world. Do not believe the rhetoric that says this is going to go away."
CORRECTION: This story has been updated to correct the description of Gainesville's location in relation to Atlanta. It is northeast of Atlanta.