April 24, 2009
Herald Sun, Australia
MEXICO CITY — Mexican officials, scrambling to control a swine flu outbreak that has killed as many as 60 people and infected possibly hundreds more in recent weeks, closed museums and shuttered schools from kindergarten to university for millions of young people in and around the capital on Friday, and urged people with flu symptoms to stay home from work.
Photo: People wearing surgical masks walking towards General Hospital in Mexico City on Friday. (Dario Lopez-Mills / AP)
“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 Calderón and other top officials Thursday night 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 also been found in the American Southwest, where officials have reported eight non-fatal cases.
Most of Mexico’s dead have been young, healthy adults, and none of them have been over 60 or under three years old, the World Health Organization said. That alarms health officials because seasonal flus cause most of their deaths among infants and bedridden old people, but pandemic flus — like the 1918 Spanish flu, and the 1957 and 1968 pandemics — often strike young, healthy people the hardest.
Mexican officials vowed to mount 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 giving the common Mexican greeting to a woman of a kiss on the right cheek. Mexico City shut museums and other cultural venues, and advised people not to attend movie theaters or other public events. Seven million students were kept from classes in Mexico City and the neighboring State of Mexico on Friday, in what local news organizations called the first citywide closure of schools since a powerful earthquake hit in 1985.
Because of the situation in Mexico, the World Health Organization will convene an expert committee 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 W.H.O. said there had been 800 cases in Mexico, 60 of them fatal, of a flu-like illness that appears to be more serious than the regular seasonal flu. Mexican officials said there were 943 possible cases.
Still, only a small number of the illnesses have been confirmed as cases of the new H1N1 swine flu, according to Gregory Hartl, a W.H.O. spokesman said. Mexican authorities confirmed 16 deaths from swine flu and said another 45 were under investigation, most of them in the Mexico City area. The C.D.C. said that 8 cases had been confirmed in the United States, and had sent teams to California and Texas to investigate.
"We are worried," said Dr. Richard Besser, the acting head of the C.D.C. "We don’t know if this will lead to the next pandemic, but we will be monitoring it and taking it seriously."
Photo: People wearing surgical masks at the General Hospital in Mexico City on Friday. (Dario Lopez-Mills / AP)
There would be no point in trying to use containment measures in the United States, he said, because the virus has already appeared in spots from San Antonio to San Diego, without any obvious connections between cases. Containment measures usually only work, he said, when a disease is confined to a small focal area.
The C.D.C. refrained from warning people not visit Mexico. Even so, the outbreak comes at an awful time for Mexican tourism officials, who have been struggling to counter the perception that the country’s drug violence has made it too insecure for travelers. The outbreak was also causing alarm among Mexicans, many of whom rushed to pharmacies to buy masks or to health clinics for checkups.
“I hope it’s not something grave,” said Claudia Cruz, 38, who took her 11-year-old son, Efrain, to a clinic Friday after hearing the government warnings about the outbreak.
Health officials urged those suffering from fever or with a cough, sore throat, shortness of breath or muscle and joint pain to seek medical attention. To avoid contracting the flu, people were urged to wash their hands frequently and take other normal precautions.
When a new virus emerges, explained Dr. Anne Moscona, a flu specialist at Cornell University’s medical school, it can sweep through the population. The Spanish flu is believed to have infected at least 25 percent of the United States population, but killed less than three percent of those infected.
The leading theory as to why so many young, healthy people die in pandemics is called the “cytokine storm,” in which vigorous immune systems pour out antibodies to attack the new virus. That can inflame lung cells until they leak fluid, which can overwhelm the lungs, Dr. Moscona said.
But older people who have had flu repeatedly in their lives may have some antibodies that provide cross-protection to the new strain, she said. And the aged cannot mount as vigorous immune responses.
Despite the alarm in recent years over the H5N1 avian flu, which is still circulating in China, Indonesia, Egypt and elsewhere, some flu experts argued that it would never cause a pandemic, because no H5 strain ever had. All previous pandemics have been caused by H1s, H2s or H3s.
Among the cases found in the United States, none had any contact with pigs, and in two sets of cases, involving a father and daughter and two 16-year-old schoolmates, those infected had contact with each other. That convinced the authorities that the virus was being transmitted from person to person.
In Canada, which was hit by the SARS epidemic in 2003, health officials urged those who recently traveled to Mexico and developed illness to immediately seek treatment.
http://www.nytimes.com/2009/04/25/world/americas/25mexico.html?em