The COVID-19 antigen self-test kits packed in a box. [Photo/WeChat account: huzhoufabu]

Anji county in Huzhou recently distributed 100,000 antigen self-test kits to towns and sub-districts in the county.

The kits, which will be used by tea pickers outside Zhejiang, are part of efforts to prevent a possible resurgence of the epidemic during the county's tea harvest season.

Huzhou recently entered the spring tea harvest season, which is expected to reach its busiest period on March 23.

The tea plantation in the city spans roughly 423,700 mu (28,246.6 hectares) this year, and nearly 430,000 tea pickers are expected to be involved in the harvest. More than 370,000 of these workers will be hired from places including Henan, Anhui, Jiangsu and Shandong.

The local government has rolled out a raft of measures to prevent an outbreak during the harvest.

Tea pickers from outside the city are required to test negative for COVID-19 within 48 hours before they are transported to Huzhou on chartered buses. Upon arrival, they have to undergo an antigen test and a nucleic acid test.

The antigen test can only be used as a supplement to nucleic acid detection, which is still the primary diagnostic tool for COVID-19 as it is 100 to 1,000 times more sensitive than the antigen test.

A positive test result on the kit must be followed up with nucleic acid testing to confirm the presence of the virus.