An Introduction to Influenza A (H1N1), or “Swine Flu”
from the Times Topics page on swine flu, as of April 30
An outbreak of swine flu in Mexico has raised concerns worldwide that the disease could be emerging as a global pandemic.
The World Health Organization raised the alert level of the fast-spreading virus on April 29, indicating that a "pandemic is
imminent." Experts say that the virus cannot be contained by closing borders or restricting travel.
The fallback position, experts said, is mitigation, the use of "nonpharmaceutical measures." They include personal ones like
washing hands and wearing a mask, occupational ones like working from home or arranging care for children who are sick
or whose schools close, neighborhood-level ones like closing theaters, museums or restaurants, and metropolitan-wide ones
like shutting a school system or canceling a major league ballgame.
The A (H1N1) swine flu, first diagnosed in Mexico, is believed to have killed 170 people and sickened about 2,500. Thus far,
the epidemic has resulted in mild illness in many of those infected, and claimed only a confirmed eight lives in Mexico. The
only death outside of Mexico has been a 22-month-old Mexican boy who died in Texas.
The Centers for Disease Control and Prevention on Thursday reported 109 confirmed cases from 11 states, up from 91
cases in 10 states on Wednesday. New York City added five new confirmed cases, bringing its total to 49. All of the cases in
New York have links to Mexico or St. Francis Preparatory School in Queens, where the virus first surfaced in New York, health
The number of confirmed cases nationwide was almost certain to grow as laboratories completed further tests on cases now
termed "likely" or "probable."
Worldwide, at least 13 countries have confirmed cases of swine flu.
Mexico's first known case, which was later confirmed, was from Perote, in Veracruz State, according to Health Minister José
Ángel Córdova. The case involved a 5-year-old boy, who recovered.
SWINE FLU QUESTIONS
History teaches that the influenza virus mutates to cause worldwide epidemic about twice a century, on average. But
scientists have yet to figure out what causes the mutations, when they will occur and what makes certain viruses more
lethal than others.
The new swine flu cases are caused by an influenza strain called H1N1, which appears to be easily passed from person to
person. The most common method of transmission is airborne, and it is also possible to become infected by touching a
surface with the virus on it and then touching one's mouth or nose. The Centers for Disease Control and Prevention is
advising people to wash their hands frequently, and also to avoid surfaces that might be contaminated.
With flu cases appearing around the world, it is clear the strain is easy to transmit; what remains to be seen is how many
more deaths will result. Most people will not have immunity to this new virus and, as it continues to spread, more cases,
more hospitalizations and more deaths are expected in the coming days and weeks.
Even a flu with a low percentage of lethality can cause a large number of deaths if vast swaths of populations are infected.
This outbreak has caused such concern because officials have never seen this particular strain of the flu passing among
humans before, said Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases. And as the
virus spreads, the likelihood that it could mutate to a potentially more lethal strain grows.
Flu experts are trying to determine if the 2009 flu shots, which contain H1N1 strain, offer any protection.
RESPONSE FROM PUBLIC HEALTH OFFICIALS
Health authorities around the world are taking extraordinary measures to combat the epidemic and mitigate its effects.
The W.H.O. raised its alert level on swine flu to Phase 5 on April 29, based on the flu's continuing spread in the United States
and Mexico. Phase 5, the next-to-highest level in the worldwide warning system W.H.O. alert system, has never been
declared since the system was introduced in 2005 in response to the avian influenza crisis. Phase 6 means a pandemic is
Global health officials have warned that it is not feasible for authorities to contain the disease by closing borders or
restricting travel. Instead, they are encouraging governments to focus on mitigating the disease's spread through public
health measures, a challenge governments are taking on with a spectrum of responses.
Experts on the global movement say the world must bow to the inevitable: closing borders would not only fail to stop the
virus, but would also cause economic collapse and possibly add to the death rate.
For the World Health Organization, mitigation is an about-face from the strategy that has contained the H5N1 avian flu,
which has caused fewer than 300 deaths. That flu's first appearance in 1997 was contained by killing every chicken in Hong
Many countries are still ignoring the advice against containment efforts. The globe is a confusing welter of bans, advisories
and alerts on some pork and some people.
Officials in Mexico shut down schools across the country and limited restaurant service in Mexico City in an effort to curb
transmission of the virus. Mexico City, one of the world's largest cities, has taken drastic preventative steps, shutting down
schools, gyms, swimming pools, restaurants, and movie theaters. Many people on the streets have donned masks in hopes
In a nationally televised speech on April 29, the Mexican president, Felipe Calderón, said that many public services would be
closed Friday through Tuesday, encompassing a long holiday weekend. Most government offices and many private
businesses will be ordered closed, restaurants, schools and museums will remain shuttered, and spectators will be barred
from all professional soccer matches.
On the American side of the border, authorities in Fort Worth, Texas announced Thursday the temporary closure of all district
schools, likely until May 12, after one confirmed case and three suspected cases of swine flu were discovered among the
On Tuesday April 28 President Obama asked Congress for $1.5 billion in supplemental funding to confront the outbreak. The
president also recommended that schools with confirmed or suspected cases of the disease "strongly consider temporarily
The United States has no plans to close international borders. Nonetheless, Customs and Border Protection agents have
stepped up efforts to spot sick travelers and are passing out travel health advisories.
As of April 29 at least 10 countries - including China, Russia, Ukraine and Ecuador - banned the importation of all pork
products. International health experts said the flu cannot be transmitted from pigs or from eating properly handled pork.
Federal officials said it would take until January, or late November at the earliest, to make enough vaccine to protect all
Americans from a possible epidemic of swine flu.
And beyond the United States and a few other countries that also make vaccines, some experts said it could take years to
produce enough swine flu vaccine to satisfy global demand.
Although production is much faster than would have been possible even a few years ago, it still may not be in time to avert
death and illness if the virus starts spreading widely and becomes more virulent, some experts said. In this country, the
biggest problem is that despite years of effort, the country is still relying on half-century-old technology to make the flu
Federal officials have not yet made a decision on whether the swine flu is enough of a threat to warrant vaccine production.
But they are taking the initial steps. A potential problem is that producing swine flu vaccine might interfere with production
of the seasonal flu vaccine for next winter.
The vaccine industry is in a much stronger position to respond now than it was five years ago, when the United States had
only two flu vaccine suppliers and was hit by a severe shortage.
Now there are five suppliers to the domestic market. And the vaccine industry, once a backwater of the pharmaceutical
industry, is attracting new investments, lured by government subsidies and higher prices for vaccines.
Shares of GlaxoSmithKline and Roche, makers of prescription flu treatments, have risen amid expectations that the swine
flu scare would lift demand for their products.
There were no immediate signs of shortages of flu drugs. Roche, the Swiss maker of the antiflu drug Tamiflu, said that day
that the W.H.O. has enough stockpiled to treat up to 5 million people, on top of millions more doses held by governments.
Tamiflu has been stockpiled for years by governments, companies and health authorities. Still, manufacturers were
increasing production and expressed anxiety that shortages could develop if governments placed huge orders.
Pharmacies in New York have reported runs on Tamiflu -- something that public health officials badly want to avoid because
the drug could eventually be needed for the truly ill.
from The Well Blog: “The Symptoms of Swine Flu” by Tara Parker-Pope (http://well.blogs.nytimes.com/2009/04/28/the-
How do I know if it’s swine flu? That’s the obvious question people around the country are asking themselves the moment
they experience a cough, sniffle or body ache.
Even under the best of circumstances, it can be tough to know if you really have the flu. I’d always thought I knew what flu
felt like until the day a few years ago that I really caught it. I was so sick, achy and bedridden that I realized all my other
bouts with “flu” were really just bad colds or upper respiratory infections. The real flu knocks you for a loop.
Swine flu can only be confirmed by a lab test. But I spoke with infectious disease expert Dr. Dan Hinthorn, director of the
division of infectious disease at the University of Kansas about what distinguishes the symptoms of swine flu from regular
“We’d all like to know the exact answer,’’ he explained. “The symptoms are quite similar between regular flu and swine flu.
Influenza ordinarily is a respiratory illness with fever, headache, sore throat, nasal stuffiness and cough. And body aches are
real common. You go to bed and feel terrible. The difference may be that some of the people who have had swine flu have
diarrhea or vomiting. That’s unusual except in children. Adults usually don’t have diarrhea with flu. It may well be that that
could be a marker, but it’s not clear yet.’’
The good news for people in the United States is that every case so far has been mild. But at what point do you call your
doctor? The very old and the very young should always see a doctor about flu. People with underlying medical conditions like
cancer, diabetes or heart disease should also check with their doctor when they develop flu symptoms. But given the
widespread fears about swine flu, even otherwise healthy people who develop symptoms should at least place a call to their