MEXICO CITY — Mexico’s top medical officer voiced optimism Thursday that swine flu has slowed in the nation hardest hit by the virus, but the World Health Organization cautioned that there is no evidence that the worst of the global threat is over.
The U.S. caseload rose slightly to nearly 130 as hundreds of schools nationwide shut their doors.
European health ministers vowed to work quickly with drugmakers to rush a vaccine into production, but U.S. health officials suggested that inoculations could not begin until the fall at the earliest.
Mexican Health Secretary Jose Angel Cordova said new cases have leveled off and that the death rate has been nearly flat for several days.
“The fact that we have a stabilization in the daily numbers, even a drop, makes us optimistic,” he said. “Because what we’d expect is geometric or exponential growth.”
12 confirmed deaths
The health ministry, which earlier said 168 people were believed dead from swine flu in Mexico, on Thursday would confirm only 12 of those deaths and would not say how many were suspected.
The WHO’s top flu official, responding to similarly hopeful remarks from other Mexican officials, sounded a more cautious note.
“For things to go up and down in a country is expected. If it didn’t do that, it would be very unusual,” Dr. Keiji Fukuda said in Geneva. “Hopefully, we’ll see more of the data of what’s going on there. But I expect even in Mexico you will see a mixed picture.”
Mexico’s top epidemiologist said the WHO was slow to react to an outbreak of atypical pneumonia that grew into the swine flu epidemic, telling The Associated Press he wants a probe to find out what happened in order to prevent a repeat.
Dr. Miguel Angel Lezana, director of the National Epidemiology Center, said it notified the Pan American Health Organization on April 16 about the outbreak in Mexico, but didn’t see any action by the WHO, the parent organization, until eight days later.
Mexico has imposed what amounts to a five-day shutdown of the country, beginning today, in hopes of slowing the virus. All but the most essential government services will be suspended, most businesses have been urged to close, and Mexicans have been encouraged to stay in their homes.
On Wednesday, the WHO said swine flu threatened to become a pandemic, and for the first time it raised its threat level to Phase 5, the second-highest. Fukuda said Thursday that there were no immediate signs that warranted declaring a Phase 6 pandemic.
Phase 5 means a virus has spread into at least two countries and is causing large outbreaks. Phase 6 means outbreaks have been detected in two or more regions of the world and that a pandemic is underway.
The only confirmed U.S. swine-flu death so far is a Mexican toddler who died this week in Texas. New cases of swine flu were confirmed Thursday in Europe, but no deaths had been reported outside North America.
Never posed risk to Obama
An aide to Energy Secretary Steven Chu apparently got sick helping to arrange President Barack Obama’s recent trip to Mexico. The aide did not fly on Air Force One and never posed a risk to the president, the White House said.
The U.S. is taking extraordinary precautions, including shipping millions of doses of anti-flu drugs to states. Scientists cannot predict what a new virus might do, and the outbreak could always resurge later.
Scientists are racing to prepare the key ingredient to make a vaccine against the strain, but it will take several months before human testing can begin. Production would not start until fall.
In hopes of avoiding confusion, the WHO announced it will stop using the term “swine flu,” opting for the bug’s scientific name, H1N1 influenza A. Obama administration officials also have referred to the virus as H1N1 in recent days.
Switzerland and the Netherlands became the latest countries to report infections.
Canada, New Zealand, Britain, Germany, Spain, Israel and Austria also have confirmed cases.
In the United States, where cases have been confirmed coast to coast, nearly 300 schools were closed Thursday, including at least 200 in Texas.
The Red Cross said it was readying an army of 60 million volunteers who can be deployed around the world to help slow the virus’ spread.
