Mexico City (AP) - Mexico readied a "temporarily closed" sign -- taking the drastic step of ordering a suspension of nonessential federal government and private business activity as it tried to squelch a swine flu epidemic. The World Health Organization ratcheted up an alert and warned that "all of humanity" is threatened.
The dire warning showed that world health officials are very worried about the potential for massive numbers of deaths worldwide from the mutated virus, even though the epidemic so far has claimed only a confirmed eight lives in Mexico and one in the United States. Roughly 170 deaths are suspected of having been caused by the virus in Mexico.
The Phase 5 alert, indicating a pandemic could be imminent as the virus spread further in Europe, prompted Mexico to announce the partial May 1-5 shutdown, Mexican Health Secretary Jose Cordova said late Wednesday.
In Washington, President Barack Obama promised "great vigilance" in confronting the outbreak which has sickened nearly 100 people in 11 states and forced schools to close. A Mexican toddler who visited Texas with his family died Monday night in Houston, becoming the first fatality in the U.S., and 39 Marines were confined to their base in California after one came down with the disease.
The virus, a mix of pig, bird and human genes to which people have limited natural immunity, has also spread to Canada, New Zealand, Britain, Germany, Spain, Israel and Austria.
"It really is all of humanity that is under threat during a pandemic," WHO Director General Margaret Chan said in Geneva. "We do not have all the answers right now, but we will get them."
In a televised address, Mexican President Felipe Calderon praised "the heroic work" of doctors and nurses and asked his countrymen to literally stay in their homes between May 1 and May 5, saying "there is no safer place to protect yourself against catching swine flu, than in your house."
"In recent days, Mexico has faced one of the most serious problems in recent years," Calderon said Wednesday night. He brushed aside criticisms that his government's response was slow, stressing several times that authorities had reacted "immediately."
School in Mexico has already been canceled until May 6. During the shutdown, essential services like transport, supermarkets, trash collection and hospitals will remain open.
Calderon said authorities would use the partial shutdown to weigh whether to extend the emergency measures, or "if it is possible to phase out some" restrictions.
The outbreak appeared to already be stabilizing in Mexico, the epicenter. Confirmed swine flu cases doubled Wednesday to 99, but new deaths finally seemed to be leveling off after an aggressive public health campaign was launched when the epidemic was declared April 23.
Although 17 new suspected deaths were reported, only one additional confirmed death was announced Wednesday night, for a total of eight countrywide. The virus is believed to have sickened as many as 2,955 people across the country, though hospital records suggest the outbreak may have peaked here last week.
The WHO said the global threat is nevertheless serious enough to ramp up efforts to produce a vaccine against the virus. It declared a Phase 5 outbreak -- the second-highest on its threat scale -- for the first time ever, indicating a pandemic could be imminent.
In the U.S., eight states closed schools Wednesday, affecting 53,000 students in Texas alone.
Obama said his administration has made sure that needed medical supplies are on hand and he praised the Bush administration for stockpiling 50 million doses of antiviral medications.
"The key now is to just make sure we are maintaining great vigilance, that everybody responds appropriately when cases do come up. And individual families start taking very sensible precautions that can make a huge difference," he said.
Ecuador joined Cuba and Argentina in banning travel to or from Mexico and Peru banned flights from Mexico. The Panama Canal Authority ordered pilots and other employees who board ships passing through the waterway to use surgical masks and gloves. An average of 36 ships per day use the canal, most from the United States, China, Chile and Japan.
In France, President Nicolas Sarkozy met with Cabinet ministers to discuss swine flu, and the health minister said France would ask the European Union to suspend flights to Mexico.
The U.S., the European Union and other countries have discouraged nonessential travel to Mexico. Some countries have urged their citizens to avoid the United States and Canada as well. Health officials said such bans would do little to stop the virus.
Medical detectives have not pinpointed where the outbreak began. Scientists believe that somewhere in the world, months or even a year ago, a pig virus jumped to a human and mutated, and has been spreading between humans ever since.
China has gone on a rhetorical offensive to squash any suggestion it's the source of the swine flu after some Mexican officials were quoted in media reports in the past week saying the virus came from Asia and the governor of Mexico's Veracruz state was quoted as saying the virus specifically came from China.
One of the deaths in Mexico directly attributed to swine flu was that of a Bangladeshi immigrant, said Mexico's chief epidemiologist Miguel Angel Lezana.
Lezana said the unnamed Bangladeshi had lived in Mexico for six months and was recently visited by a brother who arrived from Bangladesh or Pakistan and was reportedly ill. The brother has left Mexico and his whereabouts are unknown, Lezana said. He suggested the brother could have brought the virus from Pakistan or Bangladesh.
By March 9, the first symptoms were showing up in the Mexican state of Veracruz, where pig farming is a key industry in mountain hamlets and where small clinics provide the only health care.
The earliest confirmed case was there: a 5-year-old boy who was one of hundreds of people in the town of La Gloria whose flu symptoms left them struggling to breathe.
Days later, a door-to-door tax inspector was hospitalized with acute respiratory problems in the neighboring state of Oaxaca, infecting 16 hospital workers before she became Mexico's first confirmed death.
Neighbors of the inspector, Maria Adela Gutierrez, said Wednesday that she fell ill after pairing up with a temporary worker from Veracruz who seemed to have a very bad cold. Other people from La Gloria kept going to jobs in Mexico City despite their illnesses, and could have infected people in the capital.
Cordova, the Mexican health secretary, said getting proper treatment within 48 hours of falling ill "is fundamental for getting the best results" and suggested the virus can be beaten if caught quickly and treated properly. But it was neither caught quickly nor treated properly in the early days in Mexico, which lacked the capacity to identify the virus, and whose health care system has become the target of widespread anger and distrust.
In case after case, patients have complained of being misdiagnosed, turned away by doctors and denied access to drugs. Monica Gonzalez said her husband, Alejandro, already had a bad cough when he returned to Mexico City from Veracruz two weeks ago and soon developed a fever and swollen tonsils.
As the 32-year-old truck driver's symptoms worsened, she took him to a series of doctors and finally a large hospital. By then, he had a temperature of 102 and could barely stand.
"They sent him away because they said it was just tonsillitis," she said. "That hospital is garbage."
Gonzalez finally took her husband to Mexico City's main respiratory hospital, "dying in the taxi." Doctors diagnosed pneumonia, but it may be too late: He has suffered a collapsed lung and is unconscious. Doctors doubt he will survive.
Swine flu has symptoms nearly identical to regular flu -- fever, cough and sore throat -- and spreads like regular flu, through tiny particles in the air, when people cough or sneeze. People with flu symptoms are advised to stay at home, wash their hands and cover their sneezes.
AP writers Frank Jordans in Geneva, Tom Raum and Lauran Neergaard in Washington, Olga Rodriguez in Oaxaca, Mexico, Paul Haven and E. Eduardo Castillo in Mexico City, and Mike Stobbe in Atlanta contributed to this report.
Mexico is taking the drastic step of suspending nonessential federal government and private business activity as it tries to squelch a swine flu epidemic. The World Health Organization ratcheted up an alert and warned that "all of humanity" is t