More than 1,000 people have fallen ill in Mexico City in a short period of time.
An unusual strain of swine flu has been detected among victims of a large outbreak of a severe respiratory illness in Mexico, prompting global health officials, fearful of a potential flu pandemic, to scramble yesterday to try to contain the virus.
Authorities in Mexico urged people to avoid hospitals except for medical emergencies because hospitals are centers of infection. They also said Mexicans should refrain from customary greetings such as shaking hands or kissing cheeks.