WASHINGTON (CBS SF) — East Bay Congressman Mark DeSaulnier remains in critical but stable condition and is showing progress during treatment for pneumonia, his family announced Tuesday.

DeSaulnier’s sons Tristan and Tucker released an update on their father’s condition Tuesday afternoon, saying they were “heartened by all the support, strength and birthday wishes” for their dad.

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“Our Dad remains in critical condition, but is stable and continues to be characteristically resilient. While his situation remains serious, he is showing progress as his doctors continue to treat his pneumonia. His road to recovery is uncertain, ongoing, and will take time. Right now, our priority – and his – is ensuring improvement continues,” the DeSaulnier sons said.

The democratic congressman was admitted to a Washington, DC-area hospital on March 21 to treat complications from pneumonia after suffering a “traumatic rib fracture” when he fell during a run.

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“Even in the most difficult times, Dad has always had faith that California and America are strong enough to face any challenge. And we believe the same of him,” his sons said.

DeSaulnier was tested for COVID-19 and the test came back negative.

The congressman has represented California’s 11th congressional district, which includes most of Contra Costa County, since 2015.

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According to the biography on his congressional website, DeSaulnier is described as an avid runner, who has completed 21 marathons.