Georgia Gov. Brian Kemp will issue a shelter-in-place order for Georgia residents on Thursday to help stop the spread of the coronavirus, well after other states like California, Ohio, and Maryland had already taken such action.

At a Wednesday news conference, he said he issued the order now because of projections that Georgia's hospitals could be at capacity by late April if current social distancing measures remained in place.

But he also said "we didn't know...until the last 24 hours" that asymptomatic carriers could infect other people.

Medical experts have been warning about asymptomatic transmission for months.

Georgia had 4,748 confirmed cases of COVID-19 and 154 deaths as of April 1, according to the state's public health department.

Visit Business Insider's homepage for more stories.

Gov. Brian Kemp claimed that he delayed issuing a stay-at-home order for Georgia residents because he only recently learned that asymptomatic people could spread the novel coronavirus, despite medical experts warning about this type of transmission for months.

Kemp, a Republican, will officially issue a shelter-in-place order on Thursday, the Atlanta Journal Constitution reported, after more than 30 states had already taken such action to keep their residents home as much as possible and practice social distancing.

At a Wednesday press conference announcing the order, Kemp said he was finally spurred to issue the order because "modeling and data have dramatically changed for Georgia" over the previous 48 hours.

He also said the Centers for Disease Control had just announced that "indiviudals can be infected and begin to spread coronavirus earlier than previously thought, even if they had no symptoms."

"From a public health standpoint, this is a revalation and a game changer," Kemp said. He said he was following the guidance of Dr. Kathleen Toomey, the head of Georgia's Department of Public Health.

Kemp later said that "finding out that this virus is now transmitting before people see signs" was a key part in his decision to issue the shelter-in-place order.

"Those individuals could have been infecting people before they ever felt bad," Kemp said. "We didn't know that until the last 24 hours."

On March 31, Dr. Robert Redfield, director of the Centers for Disease Control, did tell WABE in Atlanta that the agency had "pretty much confirmed" that "a significant number of individuals that are infected actually remain asymptomatic. That may be as many as 25%."

But medical experts have already warned about asymptomatic transmission since February.

In late February, Chinese researchers confirmed that a 20-year-old woman who tested positive for the coronavirus but displayed no symptoms passed the virus on to five family members. Subsequent studies indicated that people could transmit the virus before they started showing symptoms.

An article published in the journal Science on March 16 estimated that for every person who tests positive for the novel coronavirus, there may be 5 to 10 times as many undetected cases.

The fear of asymptomatic transmission is just one reason why public health officials have urged people to practice social distancing, and enter precautionary self-quarantine if they come into contact with individuals who test positive for the virus.

In late March, U.S. Senator Rand Paul, a Republican from Kentucky, caused an uproar at the Capitol after he announced he had tested positive for the coronavirus despite not displaying any symptoms. Paul had continued to go to the Senate after his test but before his diagnosis, leading Senators, staff, and journalists to fear they'd been infected. Two Republican senators who spent time with Paul entered self-quarantine as a precaution.

Public health officials have called for increased testing in across the U.S. to more accurately out asymptomatic carriers, so that they can take appropriate precautions to prevent the virus from spreading.

From Friday through April 13, Georgians will be required to shelter-in-place, and schools will be closed for the remainder of the school year. Law enforcement would help enforce the order, and violators could face fines or misdemeanor charges.

Previously, Kemp had banned gatherings of more than 10 people, temporarily suspended public schools, and urged vulnerable populations to stay home. But he had resisted a stay-at-home order, the AJC reported, despite urging from mayors around the state.

As of April 1, the state had 4,748 confirmed cases of COVID-19, the disease caused by the novel coronavirus, and 154 deaths, according to the Georgia Department of Public Health.

Read more:

Many coronavirus patients are passing the virus before showing symptoms, a new study found — yet another reason for social distancing

Florida Gov. Ron DeSantis orders statewide shutdown after insisting the White House hadn't advised him to take bold action