"The elderly person in the photo is Zhang Fuye, who is 82 years old," recalled Ren, who worked with Liu to collect nucleic acid samples on March 11, adding that Zhang was not at home when they arrived.

"We found Zhang and his wife were digging potatoes in their field. Given their ages, we went to the field to do the test. Then, I pressed the shutter for Liu and Zhang," Ren said.

"Both the medical worker and the farmer are awesome. The medical worker even went to the farmland to do the test," a netizen named "Luoluo" wrote on Douyin, a popular short-video app in China.

"The medical worker did a great job and the farmer cooperated very well," another internet user named "past/past" wrote.

"The village is located deep in the mountains and villagers live in scattered places. Our medics need to tramp over hills and dales to collect nucleic acid samples one by one," said Liu, who is responsible for taking samples in Peijiazhuang village.