Updated 8:25 p.m.: Revised to include Collin County’s evening announcement of nine new positive cases.

The number of confirmed coronavirus cases in North Texas continues to rise, with some people spreading the virus in offices and recreational gatherings.

Dallas County officials announced 19 new cases of COVID-19 Friday morning, bringing the county’s total to 74.

Dallas County health officials said in a statement that “multiple clusters of transmission have been noted among attendees of recreational group gatherings and employees in office settings.”

County Judge Clay Jenkins did not respond to a request for comment about whether the county would identify the places where the virus spread. The county said in the statement that it would not release more information because of privacy concerns.

Most of the reported COVID-19 patients live in the city of Dallas, which has 51 cases. Irving has five cases; Garland and Mesquite each have four; Farmers Branch, Richardson and Coppell each have two; and Balch Springs, Carrollton, DeSoto and Cedar Hill each have one.

Dallas County health officials said earlier this week that the county was in the “mitigation” phase, meaning it must try to limit the spread of the virus by urging residents to stay home.

“The social distancing is so we can try to protect our health care system so we don’t get overrun,” Dr. Philip Huang, director of Dallas Health and Human Services, has said. “Even if we get cases, we’re slowing it down with a slower stream of people hitting the emergency departments and hospitals so that it’s at a level that can be handled.”

Of the county’s 74 patients, 53 did not require hospitalization. Of the 21 who were hospitalized, nine were admitted to intensive care.

Ages of the 74 patients cover a wide range: one is 17 years old or under; 26 are ages 18 to 40; 25 are ages 41 to 60; and 22 are over age 60.

Texas Department of Public Safety officials announced Thursday that an employee at the Carrollton DPS Mega Center had tested positive for the new coronavirus.

It was unclear whether the employee had interacted with the public.

And a Dallas police officer who tested positive for the virus Thursday was at home self-isolating, as were three other Dallas police employees who had been in close contact with the officer.

Tarrant County

Officials in Tarrant County announced 10 new coronavirus cases Friday, bringing its total to 29. Officials said two previously reported patients had recovered.

Four of those the new patients live in Arlington. Fort Worth and Lakeside each have two cases; Keller and Euless each have a case.

“We are interviewing these new patients, identifying places they’ve traveled to and reaching out to others who may have been exposed,“ Tarrant County Public Health Director Vinny Taneja said in a press release.

Collin County

Collin County officials announced nine new cases late Friday, bringing the county’s total to 27.

Three of the new cases are from Plano, two from McKinney and one each from Dallas, Frisco, Richardson and Wylie.

Five of the new patients had traveled; four had not. Their ages vary widely: One is in her 20s, two are in their 40s, three are in their 50s, two are in their 60s, and one is in his 70s.

Plano officials said Friday that a Plano police officer had tested positive for coronavirus. Officials said they believed the officer had been infected by traveling out of state, but they didn’t say where.

The officer was at work March 13 but left after feeling ill, officials said. He has been self-isolating at home in the days since.

“He has not had that many contacts with other people,” city spokesman Steve Stoler said.

Other Plano employees who traveled to the same area, which the city did not identify, are undergoing testing for the virus. City officials estimate the officer came into contact with two or three other people.

A 64-year-old Plano resident died Tuesday after contacting the virus.

Denton County

Denton County officials confirmed six new cases Friday, for a total of 15.

County officials said 11 people were isolated at home. Nine cases were related to travel. At least three were a result of local transmission.

Five firefighters in the Denton County town of Roanoke were in isolation after possible exposure to the virus Friday morning while responding to a medical emergency, and the firefighters were removed from duty, spokeswoman Morgan Roundy said.

The department was awaiting test results on the patient before deciding whether to return the firefighters to duty.

Ellis County

Health authorities in Ellis Counts identified a second case of coronavirus, three days after a Maypearl resident tested positive. The second patient is from Palmer.

Health officials were trying to identify people who had contact with both residents.

Kaufman County

Forney Mayor Mary Penn declared a state of disaster and public health emergency in the Kaufman County town Friday afternoon. The declaration was made to “help reduce the spread of the disease and activate resources" to help the city respond, a statement said.

Staff writer Marc Ramirez and special contributor Teri Webster contributed to this report.