This is developing news here in Beijing about treatment of those who hold Mexican passports. It is based on first-hand reports from people I trust:

- A family of tourists -- two parents; a son age 8; and daughters ages 6 and 4 -- were staying in a five-star Beijing hotel. Like all foreigners in China, they had presented their passports for inspection on arrival. Their passports were from Mexico. At 4 am last night they heard a pounding on the door. Public-security officials asked them to come to the hospital for a few quick tests. In fact they were taken to a hospital and not allowed to leave. They received no drugs or treatment of any sort and were placed in a room where the beds and sheets still bore the marks of the previous ill and bleeding patients. They managed to contact Mexican officials by phone -- which was the first the Mexican government had heard of their situation. There is no indication that they are sick. They were assured that they would be treated as well as "any Chinese citizen." (!) This evening, another family of three has been taken from a hotel because they are Mexican.

- As international flights arrive in Beijing, from any destination, passengers are being asked to show their passports before the plane comes to the terminal. Those with Mexican passports are not allowed to enter the city. They have been taken to a hotel for quarantine and are still there. Some 40 to 50 people are now being detained in this way. To be clear, this is not being applied to people who've recently been to Mexico, or who are showing signs of disease, or who have been exposed in some other way. It has been purely a matter of whether they are Mexican citizens.

- A Mexican official in Guangzhou booked a round trip flight to Cambodia. On arriving back from Cambodia (ie, a million miles away from Mexico), he too has been detained, on the basis of his passport.

You can understand why China is nervous, given its dense urban populations and its experience with SARS. You can understand quarantines based on recent presence in a diseased area or possible exposure to diseased people. You can comprehend why direct flights between Mexico and China have for now been called off.

But there is no decent reason for quarantine and detention based solely on nationality. To the best of my information, this blanket quarantine of Mexican citizens is not being applied anyplace else on earth. Let's hope this is a panicky mistake by Chinese and Beijing-area officials and will soon be reversed. It is also worth recognizing the overall aplomb and openness that the Mexican government has been showing in handling the flu outbreak.