It seems that only Southeast Asian countries have heard that Vietnam will investigate, and other countries will not.
Moreover, we didn't encounter the legendary extortion during the transit. It's just that when Cambodia transited Laos (by land, to 4,000 US islands), we added a management fee of one yuan, but we didn't have much money and gave it to them.
Therefore, according to my experience from June, 5438 to October, 2008, Cambodia, Laos and Thailand will not check their health certificates, I am sure!