The number of Georgia cases of the new coronavirus has jumped to 64 – the biggest 24-hour increase of COVID-19 cases the state has seen.

Citing that disease toll, Gov. Brian Kemp on Saturday declared a public health emergency for the state. He called the situation “an unprecedented public health threat.’’

Many of the Georgia patients are hospitalized and have no recent travel history to virus hot spots, Kemp said in a somber address from the Governor’s Office.

Cobb is the hardest-hit county, with 15 coronavirus cases. It’s followed by Fulton’s 11, DeKalb’s eight and Bartow’s seven.

The cases were bound to increase since the state gained more capacity for testing patients. That ability was hamstrung for weeks as the CDC was forced to correct flaws in its initial testing kits.

The testing lag has affected the nation as well.

Kemp said the state Public Health Lab now is testing 100 specimens per day, and will soon ramp up to 200 daily, with the addition of of new equipment and more staff.

The state’s emergency management operations center has been activated, and Kemp said Georgia is working to establish testing centers across the state.

Georgia’s boards governing physicians and nurses will be allowed to grant temporary licenses to applicants licensed in other states.

By declaring a public health emergency, the governor said, the state Department of Public Health will be allowed to direct swift action to fight the pandemic “in extraordinary circumstances.”

Kemp noted the potential for the state’s medical providers to be overwhelmed. “The capacity of our health care system remains at the forefront of my mind as we prepare for more local transmission,” he said.  Kemp cited the potential surge of patients at health care facilities. Unless that’s mitigated, he said, “We risk a run on critical resources for the sickest patients.”

He said he consulted Friday with epidemiologists, who recommended “social distancing.’’ hat’s a public health practice that seeks to prevent sick people from coming into close contact with healthy people in order to reduce opportunities for transmission. It can include canceling group events or closing public spaces, as well as individual decisions such as avoiding crowds. Kemp has urged faith-based organizations to cancel services in order to reduce the potential for transmission.

Such extraordinary measures are being used amid the problem of having no medication treatment or vaccine for COVID-19. Though most people who get the disease will have mild cases and recover, it is potentially deadly for older people and those with underlying medical conditions.

Kemp has called for a special session of the General Assembly to convene Monday to ratify the emergency action through a joint resolution. More than 20 states have declared emergencies over the virus.

Kemp’s move Saturday constitutes Georgia’s first ever public health emergency, state officials said.

“I do not take this action lightly,’’ Kemp said. “We must remain supportive of one another [and] pray for our fellow Americans. We are in this fight together.’’

The Georgia declaration follows President Trump’s declaration Friday of a national emergency to free up $50 billion in federal resources to combat coronavirus.

Trump said he was “urging every state to set up emergency operations centers effective immediately.”

All the states but one have reported positive tests for COVID-19, with more than 2,200 cases across America. At least 49 people have died — 37 in Washington state, which now reports at least 568 cases; five in California, two in Florida, one each in Colorado, Georgia, Kansas, New Jersey and South Dakota.

Georgians can now go online to get updates on the number of coronavirus cases in the state. A newly created Public Health website gives information on cases, plus their location by county.

State officials also said Friday that a quarantine space for people who test positive for COVID-19, don’t need hospitalization but are unable to self-isolate is under construction in Monroe County, south of Atlanta.

The quarantine space, on the Georgia Public Safety Training Center campus, will be able to accommodate 20 temporary housing units. The state earlier this week created a similar set-up at Hard Labor Creek State Park, east of Atlanta.