MAY 1, 2009
"I've got some bad news."
The voice on the conference call last week was Frank Plummer, a Canadian scientist who had just spent 24 hours analyzing virus samples from 51 seriously ill people in Mexico.
The news: Seventeen people carried a completely new type of flu virus, one which had its origin in pigs. Flu from swine, which can be fatal, has rarely made the jump to humans -- much less appeared in so many people at once. Within minutes, Mexico's health minister grabbed a red-telephone hotline to President Felipe Calderón. "Mr. President, I need to see you urgently. It's a matter of national security."
A picture is now emerging of how U.S. and Mexican officials, with a key assist from a Canadian government lab, first realized they faced a new type of disease and began racing to isolate its earliest origins. Until recently, Mexico was widely assumed to be ground zero. Now, however, some California doctors are questioning that.
The four earliest confirmed cases are divided evenly between California and Mexico. In fact, it appears two children in California got sick in late March, several days before the first two known Mexico cases in early April.
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Within a few hours of Dr. Plummer's April 23 conference call last week, Mexico's cabinet decided to close schools in Mexico City, a move that later was expanded nationwide. Restaurants, bars and many other businesses have shuttered in Mexico City, turning the city into a virtual ghost town. This weekend, all professional soccer games are to be played to empty stadiums.
But something may have been brewing in Mexico as early as mid-March, when health officials say they first noticed a slight uptick in patients with severe pulmonary problems such as pneumonia. A/H1N1 flu can cause pneumonia.
At the time, the slight increase didn't cause much worry. An average of 20,000 people die each year from pneumonia in Mexico.
And almost no one expected a potential new pandemic to begin in North America, medical experts say. New flus often originate in parts of Asia, where poor farming families live in close proximity to domesticated animals such as birds and pigs, enabling dangerous animal viruses to jump to humans.
[snip]
Normally, bird and swine viruses aren't good at spreading from human to human, which helps limit the damage to people in direct contact with animals. The latest virus, however, is an unusual hybrid of pig, bird and human flu bugs. It also has the scary ability to leap from human to human. Thousands of people may have already been infected.
"We're in unprecedented territory really," said Richard Webby, a virologist at St. Jude's Children's Research Hospital in Memphis, Tenn., which operates a laboratory that works with the World Health Organization. So far, the virus is treatable with antiviral medicines. It appears less deadly than first thought,as long as good medical care is within reach.
In Mexico, one early warning sign occurred in a dusty village in Mexico's eastern Veracruz state called La Gloria, which sits near an industrial pig farm. An unusual outbreak of respiratory disease began there on March 9 and ended April 13, affecting some 600 villagers, including Edgar Hernandez, a skinny 5-year-old with spiky hair and Cheshire-cat grin.
"Mom, I don't feel well," Edgar told his mother, Maria del Carmen, one morning in early April. He had a high fever, so she took him to a nearby clinic, waiting in line so long with other people suffering from flu-like symptoms that Edgar fell asleep.
The doctor diagnosed flu, and prescribed an antibiotic and paracetamol. Within three days, Edgar was fine, save a lingering cough. State health officials, alerted to the outbreak, turned up in La Gloria March 28 and spent a week taking samples from 43 residents.
By April 8, Edgar's sample and one other tested positive for type "A" flu (the kind that usually arrives between early winter and early spring in temperate climates) but had to be sent away for more sophisticated testing before doctors could start to figure out the true implications.
A similar thing was happening in San Diego, where scientists from the Naval Health Research Center there were conducting a trial for a new diagnostic test for influenza. During the first week in April, the center collected two samples, from a 10-year-old boy and 9-year-old girl, that turned out to be neither a known seasonal flu virus, or a bird flu. Both samples were sent to the Centers for Disease Control for further testing, on April 14 and 17.
Pinpointing the disease's origin is proving to be tricky. The fact that some people have gotten sick without needing hospitalization suggests the virus may have floated around undetected before late March.
Well before scientists were solidly on its trail, the A/H1N1 virus claimed its first known victim. Adela Maria Gutierrez was a 39-year-old accountant and mother of three who worked as a census taker for Mexico's tax office, a job that sent her knocking door to door, contacting hundreds of people. None appear to have gotten sick, say local health officials.
She got sick on April 1. A few days later, she showed up at the emergency room of an Oaxaca City hospital on April 9 -- turning blue from a lack of oxygen. Her heart was racing abnormally quickly as well.
Doctors struggled to figure out what was wrong. One test showed up positive for coronavirus, a rare bug that can cause respiratory distress and which was responsible for the SARS outbreak. But the next test was negative.
"It was an unusual case. When we thought it was avian flu, we went on alert," said Gerardo Pérez Lescas, head of intensive care at the Oaxaca hospital.
Ms. Gutierrez's condition deteriorated rapidly. She died April 13, leaving her doctors "completely in the dark," says Alejandro López Ruiz, chief of epidemiology. The next morning he got on a plane to Mexico City, carrying vials of Ms. Gutierrez's lung samples for further testing.
That same day, April 14, Miguel Angel Lezana, Mexico's top government epidemiologist, was sitting at his desk when he got a call from the director of the National Institute for Respiratory Diseases, a specialized hospital in Mexico City. The hospital had noticed an unusual number of severe pneumonia cases. Adding to the mystery, most appeared in otherwise healthy adults. And flu season was already over.
"That was the first point in which I got a little worried," says Dr. Lezana. Two days later, given the flu outbreaks in Veracruz, Oaxaca and now Mexico City, he issued a national health alert for influenza, notifying the regional office of the World Health Organization.
Still, health officials in Mexico suspected it was merely a particularly nasty regular flu. "Our hypothesis was that we were faced with an ordinary influenza that for some reason was extending beyond the normal time," says Dr. Lezana.
Not so in the U.S. That same day, CDC officials roped in Michele Ginsberg, chief of community epidemiology in San Diego's Health & Human Services Agency. The CDC told her that both California children had been infected with what may be a new type of swine flu. Most worrying, the children lived 160 miles apart, and neither had been around pigs.
The implication: They may have contracted the virus from other humans.
"This could be the big one," Dr. Ginsberg told her co-workers, referring to a flu pandemic that has long been predicted by public-health experts.
Dr. Ginsberg moved swiftly. She and her colleagues obtained blood samples and nasal swabs from the infected boy's family and sent them to the CDC. They put in 18-hour days.
On April 17, the CDC -- by then aware of Mexico's health alert -- talked to Dr. Lezana in Mexico to describe their suspicions. "This time of year influenza is supposed to be dying down," said Michael Shaw of the CDC's influenza division. "That's one of the first alarm bells -- they were detecting influenza, they couldn't tell what it was, and the number of cases was increasing."
On Saturday morning, April 18, Eduardo Sada, a respected epidemiologist, was playing tennis when he was interrupted by a phone call from a colleague at Mexico's health ministry summoning him to the office for an emergency. Dr. Sada said he needed to go home first to take a shower. "Forget the shower, come right away," the ministry official responded.
One hour later, Dr. Sada was at the epidemiology center in the south of the city with 60 grim-faced colleagues, grappling with the surge of pneumonia cases. The symptoms were strikingly similar: a high fever, bone-rattling body aches and pounding headaches. Acute respiratory problems, and death, could follow quickly.
Dr. Sada and his colleagues worked into the night to create a questionnaire to determine the scope of the problem. On Sunday morning, they fanned out, questionnaires in hand, to visit the city's largest hospitals.
By 6 p.m., they had the data in hand: In the previous 24 hours, 120 people had been admitted with A-type influenza. Six had died.
"We knew then we were in the middle of an influenza outbreak," says Dr. Sada.
Early that week, Dr. Lezana sent 51 samples from people with flu-like symptoms to Canada's National Microbiology lab in Winnipeg. After more than a day of testing, the lab called with the grim news. "My heart sank," he says. "We not only had 17 positive samples, but the cases were in the capital and three states."
On Friday, after treating ill and dying patients from dawn to dusk, Dr. Sada went home, hugged his 2-year-old son and his wife, broke down and cried. "I told my wife it was the saddest day in my life," says Dr. Sada. "I had treated a young person who I thought was going to die, and I knew that many other people were going to die."
hat-tip Monotreme
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