Moves by the US, Japan and others to mandate Covid-19 tests for passengers arriving from China reflect global concern that new variants could emerge in its ongoing explosive outbreak ` and the government may not inform the rest of the world quickly enough. There have been no reports of new variants to date. But given the country`s track record, the worry is that China may not be sharing data on any signs of evolving strains that could spark fresh outbreaks elsewhere.

The US, in announcing a negative test requirement on Wednesday for passengers from China, cited both the surge in infections and what it said was a lack of information, including the genomic sequencing of the virus strains in the country. Japanese Prime Minister Fumio Kishida expressed a similar concern about a lack of information when he announced a testing requirement for passengers from China earlier this week.