Congressman Mark DeSaulnier in Critical Condition Following Battle With Pneumonia

Representative Mark DeSalunier is now in "critical condition" after developing pneumonia.

The Democratic congressman, who represents California's 11th district, has tested negative for COVID-19, the disease caused by the novel coronavirus, according to a Saturday statement from his office. He was first admitted to the hospital last Friday.

"Congressman DeSaulnier was admitted to the hospital to treat complications of pneumonia from a traumatic rib fracture that occurred after falling during a run. He was in serious, but stable condition, and the hospital later advised he was COVID-19 negative," the statement said.

"Unfortunately, Congressman DeSaulnier's condition has deteriorated and he is in critical condition. The doctors are doing everything they can to care for the Congressman. Mark's family and staff appreciate your thoughts and prayers during this very difficult time," it added.

The 67-year-old was first elected to Congress in 2014. He previously served as a state senator in California and as an assemblymember. DeSaulnier serves on the House Committee on Oversight and Reform, the Committee on Transportation and Infrastructure, the Committee on Education and Labor and the Committee on Rules.

Pneumonia often develops in serious cases of COVID-19, but according to the congressman's statement, that has been ruled out in his case. At least two other members of congress have been confirmed to have been infected by the coronavirus. Representative Mario Diaz-Balart, a Florida Republican, and Representative Ben McAdams, a Democrat from Utah, both announced on Wednesday that they had contracted the novel virus.

"It's a tricky bug because just when I thought I was over it or I was pretty close to getting over it, the fever will come back," Diaz-Balart said in an interview with NBC Nightly News on Saturday. "But again, not as bad as it was originally, and I think hopefully the worst is passed."

As more and more testing has been conducted in the U.S., the number of confirmed cases of coronavirus has ballooned over the past week. The U.S. now has the fourth-highest number of cases of any country in the world, with more than 26,000, according to a tracker by John Hopkins University.

Globally, more than 310,000 people have contracted the virus. More than 93,000 have already recovered and over 13,000 have died. In the U.S., only 176 people are known to have recovered, while 340 have died.

While the current death rate appears to stand at about 4 percent around the world, health experts have estimated that it is actually lower, suggesting it may be 2 percent or less. They have noted that many people who contract coronavirus are asymptomatic and may carry the infection without being aware.