As the coronavirus outbreak began sweeping across the country last month, Julio Ramirez, a 43-year-old salesman in San Gabriel, Calif., came home from a business trip and began feeling unwell, suffering from a fever, cough and body aches. By the next day, he had lost his sense of taste and smell.

His wife, Julie Murillo, took him to an urgent care clinic several days later, where he was so weak he had to be pushed in a wheelchair. Doctors prescribed antibiotics, a cough syrup and gave him a chest X-ray, but they did not test for the coronavirus, she said. Just over a week after he returned from his trip and not long after President Trump declared a national emergency over the outbreak, Ms. Murillo found him dead in his bed.

"I kept trying to get him tested from the beginning," Ms. Murillo said in an interview. "They told me no."
Frustrated, Ms. Murillo enlisted friends to call the C.D.C. on her behalf, asking for her husband to be tested for the coronavirus post-mortem. Then she hired a private company to conduct an autopsy; the owner pleaded for a coronavirus test from local and federal authorities.

On Saturday afternoon, Ms. Murillo received a call from the Los Angeles County Department of Public Health, she said. The health department had gone to the funeral home where her husband’s body was resting and taken a sample for a coronavirus test. He tested positive.

A spokesman for the health department did not respond to questions about Mr. Ramirez, and it was not clear whether any systematic post-mortem testing was being conducted beyond his case.