THE NEW YORK TIMES
04/25/2009
MEXICO CITY — Mexican officials, scrambling to control a swine flu outbreak that has killed as many as 61 people and infected possibly hundreds more in recent weeks, closed museums and shuttered schools for millions of students in and around the capital on Friday and urged people with flu symptoms to stay home from work.
"We're dealing with a new flu virus that constitutes a respiratory epidemic that so far is controllable," Mexico's health minister, Jose Angel Cordova, told reporters after huddling with President Felipe Calderon and other top officials to come up with an action plan. He said the virus had mutated from pigs and had at some point been transmitted to humans.
The new strain contains gene sequences from North American and Eurasian swine flus, North American bird flu and North American human flu, according to the Centers for Disease Control and Prevention. A similar virus has been found in the Southwestern United States, where officials have reported eight nonfatal cases.
Most of Mexico's dead were young, healthy adults, and none was over 60 or under 3 years old, the World Health Organization said. That alarms health officials because seasonal flus cause most of their deaths among infants and bedridden older people, but pandemic flus — like the 1918 Spanish flu, and the 1957 and 1968 pandemics — often strike young, healthy people the hardest.
Mexican officials promised a huge immunization campaign in the capital in the coming days, while urging people to avoid large gatherings and to refrain from shaking hands or greeting women with a kiss on the right cheek, as is common in Mexico.
Mexico City shut museums and other cultural venues and advised people not to attend movies or public events. Seven million students, from kindergarten to college, were kept from classes in Mexico City and the neighboring state of Mexico on Friday, in what local news organizations called the first citywide closing of schools since a powerful earthquake in 1985.
Because of the situation, the World Health Organization planned to consider raising the world pandemic flu alert from 3 to 4. Such a high level of alert — meaning that sustained human-to-human transmission of a new virus has been detected — has not been reached in recent years, even with the H5N1 avian flu circulating in Asia and Egypt, and would "really raise the hackles of everyone around the world," said Dr. Robert G. Webster, a flu virus expert at St. Jude Children's Research Hospital in Memphis.
Mexico's flu season is usually over by now, but health officials have noticed a significant spike in flu cases since mid-March. The WHO said there had been 800 cases in Mexico in recent weeks, 60 of them fatal, of a flulike illness that appeared to be more serious than the regular seasonal flu. Mexican officials said there were 943 possible cases.
Still, only a small number have been confirmed as cases of the new H1N1 swine flu, said Gregory Hartl, a WHO spokesman. Mexican authorities confirmed 16 deaths from swine flu and said 45 others were under investigation, most of them in the Mexico City area. The CDC said that eight nonfatal cases had been confirmed in the United States, and that it had sent teams to California and Texas to investigate.
"We are worried," said Dr. Richard Besser, the acting head of the CDC. "We don't know if this will lead to the next pandemic, but we will be monitoring it and taking it seriously."
There is no point in trying to use containment measures in the United States, he said, because the swine flu virus has already appeared from San Antonio to San Diego, without any obvious connections among cases. Containment measures usually work only when a disease is confined to a small area, he said.
Health officials urged anyone with a fever, a cough, a sore throat, shortness of breath or muscle and joint pain to seek medical attention.
When a new virus emerges, it can sweep through the population, said Dr. Anne Moscona, a flu specialist at Cornell University's medical school. The Spanish flu is believed to have infected at least 25 percent of the U.S. population, but killed less than 3 percent of those infected.
Among the swine flu cases in the United States, none had any contact with pigs; cases involving a father and daughter and two 16-year-old schoolmates convinced the authorities that the virus was being transmitted from person to person.
The CDC refrained from warning people not to visit Mexico, but the outbreak was causing alarm among Mexicans, many rushing to buy masks or get checkups.
