An unknown respiratory illness has claimed a third life at the skilled nursing and assisted living unit of a sprawling continuing care retirement community in Northern Virginia.

Officials announced this week that lab testing still had not confirmed the source of the illness, which has sickened 63 residents and 19 staff members since it first took hold June 30.

The outbreak has so far been confined to the single, 236-resident Garden Ridge unit at Greenspring Retirement Community.

No new cases had been reported over the past 24 hours, Dan Dunne, Erickson Living’s director of external communications, told McKnight’s Senior Living on Wednesday afternoon.

“There have also been no new hospitalizations related to respiratory illness in the past few days,” he said.

Officials with the Fairfax County Health Department and the Centers for Disease Control have tested 17 samples, with negative results for Legionnaires’ disease and a range of common viruses and bacteria-borne pathogens.

Benjamin Schwartz, director of epidemiology and population health at the Fairfax County Health Department, reassured the public that Greenspring’s operator has been keeping his agency abreast of resident condition changes.

The Washington Post reported the community had stepped up its sanitary and quarantine measures and stopped some new admissions. 

In a July 10 email notice cited by The Post, Greenspring Administrator Donna L. Epps said symptoms of the respiratory illness included fever, coughing and body aches. Although they typically recede in five to seven days, she said some cases had progressed to pneumonia.