His parents, in their late 40s, were skeptical. His father, Mr. Wu said, tries to stay away from political discussions. His mother was supportive of the ruling Communist Party.

Dinnertime discussions often devolved into shouting matches. But they had nowhere else to go.

Mr. Wu had not gone home intending to change anybody’s mind on anything. He and his parents are close, despite their ideological differences. He had always avoided bringing up delicate topics during his visits to Anhui, which were usually brief.

It was during a phone call in early January, before Mr. Wu had returned to Anhui that they first discussed the mysterious new sickness in central China.

It didn’t seem serious, his parents said.

But at their home in the following weeks, Mr. Wu saw more and more signs of distress from Wuhan on Weibo, a popular Chinese platform akin to Twitter. After the state news media played down the virus’s significance, he burrowed under China’s firewall to read foreign news reports.

His parents, like many older Chinese, do not use Weibo. They remained unperturbed.

Over time, though, recognition of the gravity of the epidemic became unavoidable.

“Things just got out of control. You could see people dying at home,” Mr. Wu said. “I just felt like more people should know about this, and I should open myself to more conversations about this — at least with my parents, who I can trust.”