Mexican authorities shut schools across the country and tried to follow up with families of swine flu victims in a bid to stop the virus' spread, as the probable death toll rose to 152.
The Mexican outbreak has sparked global concern as rising cases are detected around the world, and the World Health Organization has raised its flu pandemic alert level from three to four, signaling a "significant increase in risk of a pandemic."
The outbreak has prompted fears that the world may finally be experiencing the flu pandemic that health officials have been warning about for years.
Officials have confirmed 20 people died from the disease, while the number of cases under observation in Mexico has risen over 1,600.
Adding to Mexico's woes, a moderate 5.6-magnitude earthquake rocked the country shortly before noon (1700 GMT) Monday, causing panicked residents to run out on Mexico City streets earlier cleared by flu fears.
"All education activities across the country are suspended from next Tuesday to May 6," Cordova said during a news conference during the quake.
Schools in Mexico City, the heart of the epidemic, were already closed last Friday.
"We're in the decisive moment of the crisis. The number (of deaths) will continue rising," Cordova added.
As travelers returned from trips to Mexico, Europe's first cases were confirmed in Britain and Spain.
The United States and Britain also advised against non-essential travel to Mexico.
With the capital's zoos, museums, churches, courts and many restaurants already closed in the urban area of some 20 million, Mexico City aimed to shut down businesses too, despite an economy hard hit by the crisis and already suffering from the flu outbreak.
The moves, including talks with business leaders and the closures of many restaurants and bars, were likely to be met with reluctance in a country already battered by the economic crisis.
The Mexican stock exchange ended trading down by 3.34 percent Monday, in a drop attributed to the flu outbreak, and the peso fell sharply to close at 14.10 to the dollar, compared with 13.40 the previous day, according to private bank Banamex.
Four days after the first alert of swine flu in Mexico, the country's Institute of Social Security launched a campaign calling on families of people who have caught the disease to present themselves to doctors.
The government has been criticized for failing to respond quickly enough to the first signs of the flu and of failing to quarantine close family members who could catch the disease or pass it on.
"It's a fundamental step in containing the epidemic," the institute said in a statement.
The World Health Organization has warned the new strain of flu, apparently born when human and avian flu viruses infected pigs and became mixed, could further mutate.
Meanwhile British pharmaceutical giant GlaxoSmithKline said it had provided 100,000 packs of an anti-viral drug to Mexican authorities.
US officials Monday urged Americans to stay calm but warned there will likely be more cases of swine flu, and possibly deaths.
After Mexico, the United States has so far recorded the highest number of cases, with at least 40 confirmed, non-fatal, swine flu patients in five states.