The schools and museums are closed. Sold-out games between Mexico's most popular soccer teams are being played in empty stadiums. Health workers are ordering sickly passengers off subways and buses. And while bars and nightclubs filled up as usual, even some teenagers were dancing with surgical masks on.
Across this overcrowded capital of 20 million people, Mexicans are reacting with fatalism and confusion, anger and mounting fear at the idea that their city may be ground zero for a global epidemic of a new kind of flu — a strange mix of human, pig and bird viruses that has epidemiologists deeply concerned.
Tests show 20 people in Mexico have died of the new swine flu strain, and that 48 other deaths were probably due to the same strain. The caseload of those sickened has grown to 1,004 nationwide, Mexico's Health Secretary Jose Angel Cordova said.
Authorities in the capital responded on Friday with a sweeping shutdown of public places and events, urging people to stay home if they feel sick and to avoid shaking hands or kissing people on the cheeks.
Mexicans quickly got the message — and wanted to make sure their family members did, too. Cristina Ceron, a 55-year-old waitress, called her daughter as soon as she got off work. "Please keep your mouth covered. And don't you eat street food," she pleaded through a white surgical mask.
President Felipe Calderon said his government only discovered the nature of the virus late Thursday, with the help of international laboratories. "We are doing everything necessary," he said in a brief statement. The outbreak even hit Mexico's beloved national pastime — two sold-out football matches Sunday — Pumas vs Chivas and America vs Tecos — will be played in empty stadiums to prevent the spread of the disease.
Health workers also staffed the international airport and bus and subway stations, handing out masks and trying to steer away anyone who appeared sick.
It may be too late to contain the outbreak, given how widespread the known cases are. If the confirmed deaths are the first signs of a pandemic, then cases are probably incubating around the world by now, said Dr Michael Osterholm, a pandemic flu expert at the University of Minnesota. No vaccine specifically protects against swine flu, and it is unclear how much protection current human flu vaccines might offer.