China's government says passengers at Shanghai's Pudong International Airport will be screened for bird flu.
Effective immediately, passengers entering or leaving China will be asked to fill out a health declaration form and have their temperature checked.
Any passenger whose body temperature is greater than 38 degrees (Celsius) will be further examined, and if the person has been in an area affected by bird flu, he or she will be required to undergo treatment at a hospital.
Meanwhile, China's official Xinhua news agency quotes a health ministry official as saying the bird flu virus isolated from human patients in China is slightly different from that found in humans in Vietnam.
However, the ministry says the changes do not make the virus any easier to spread.