From: senaey fethi (firstname.lastname@example.org)
Date: Mon Apr 27 2009 - 04:19:11 EDT
Swine Flu: Who is at risk? What are the symptoms?
April 27, 2009
By Jeremy Laurance
Q: What is swine flu?
A: Much the same as human flu – but in pigs. The worry is that pigs are excellent hosts for the virus. And because they are genetically close to humans, they can pass the virus to us more easily than birds can. The great fear over the past decade has been that the avian flu virus, H5N1, would infect pigs which would act as a reservoir for its transmission to humans. Luckily for the world, apart from a few isolated outbreaks, this did not happen.
Q: How worried should we be?
A: At this stage, no one knows. The virus that has caused the outbreak is a strain of the H1N1 type that contains bird, pig and human genes in a combination never seen before. Immunity to it will thus be limited. Scientists are working to establish the precise nature of the virus, the symptoms it causes and its capacity to cause disease and death.
Q Has swine flu infected humans before?
A: Yes. There have been rare cases since the 1950s, mostly in people such as farmers who work directly with pigs. In Europe, 17 cases have been reported since 1958. In the US, an outbreak at a military camp in New Jersey in 1976, infected over 200 soldiers, of which 12 were hospitalised and one died.
Q What are the symptoms of swine flu?
A: Similar to ordinary human flu – cough, sudden fever, headache, muscle pains. In severe cases, it may lead to pneumonia, multi-organ failure, and death. The incubation period for ordinary human flu is two to five days.
Q: Can it be treated?
A: Yes – up to a point. Early indications are that patients in Mexico and the US have been successfully treated with the antiviral drugs Tamiflu and Relenza. These drugs cannot prevent flu but they can limit its severity, and thus save lives, if taken as soon as symptoms develop. However, the swine flu has proved resistant to older anti-virals such as amantadine.
Q: Is Britain prepared for a pandemic?
A: Better than it was five years ago. A pandemic plan has been prepared detailing action by everyone from pharmacists, who will hand out anti-viral drugs, to hospitals handling the seriously ill, to mortuaries which may have to be temporarily expanded. Over 14 million courses of Tamiflu have been stockpiled and the Government announced last year it was doubling the amount to provide enough for half the population.
Q: How bad might a pandemic be?
A: At its worst, it could have a devastating global impact, greater than a terrorist attack, nuclear accident or environmental disaster. The World Health Organisation estimates that a mild pandemic could cause up to 7.5 million deaths. In the UK, Sir Liam Donaldson, the Government's Chief Medical Officer, has said that in the worst case scenario the country could face up to 750,000 deaths. However, in the flu pandemics of 1957 and 1968 most victims recovered. There was no panic, cities did not empty, travel did not come to a halt and economies weren't devastated. Each of those pandemics killed 50,000 people in the UK and around one million worldwide. In a normal year, flu kills 12,000 to 20,000 mainly elderly people in Britain and 250,000 around the world.
Q: Who is at greatest risk?
A: In Mexico, the virus appears to be targeting those aged 20 to 40. This is not unusual – the same occurred during the worst pandemic of the last century, in 1918, when 20 to 40 million people died. Young healthy people with strong immune systems react most powerfully to the virus but the very strength of their reaction produces inflammation and secretions in the lungs which can be overwhelming. In the US, the virus appears to be targeting children who are suffering only mild illness. The difference in the two countries is so far unexplained. One hypothesis is that a second virus may be circulating in Mexico which is interacting with the swine flu virus to produce more severe symptoms.
Q: How can I protect my family?
A: By acquiring a stock of anti-viral drugs such as Tamiflu or Relenza, available only on prescription at an NHS cost of around £20 for a course of 10 doses (enough for one person). Otherwise, the best defence is strict personal hygiene. It is hard to better the advice printed by the 'News Of the World' on 3 November 1918: "Wash inside nose with soap and water night and morning; force yourself to sneeze night and morning, then breathe deeply. Do not wear a muffler, take sharp walks regularly and walk home from work; eat plenty of porridge." Porridge is, of course, a known cure-all – but the rest of the advice holds as true today as it did then.
Q: Is there a vaccine against it?
ANot in humans (there is in pigs). Ordinary seasonal flu vaccine for humans might offer some protection because there are similarities between the H1N1 human flu viruses and the new H1N1 pig flu virus. Investigations are under way to see if the seasonal vaccine would have a protective effect but those will "take some time".
Q: Why has this outbreak started in Mexico and the US?
A: No one knows, but it is certainly a surprise. The next threat was expected to come from the Far East. Avian flu has spread through poultry populations, and 400 humans have been infected, 250 of whom have died. Health experts warned that a small mutation to the virus could turn a rare but lethal disease into one which could threaten the entire planet. Now, the threat has emerged – but on the other side of the world.
Q: Is it safe to eat pork?
A: Yes. Cooking destroys the virus.
By MIKE STOBBE, AP Medical Writer Mike Stobbe, Ap Medical Writer Sun Apr 26,
ATLANTA – As reports of a unique form of swine flu erupt around the world, the inevitable question arises: Is this the big one?
Is this the next big global flu epidemic that public health experts have long anticipated and worried about? Is this the novel virus that will kill millions around the world, as pandemics did in 1918, 1957 and 1968?
The short answer is it's too soon to tell.
"What makes this so difficult is we may be somewhere between an important but yet still uneventful public health occurrence here — with something that could literally die out over the next couple of weeks and never show up again — or this could be the opening act of a full-fledged influenza pandemic," said Michael Osterholm, a prominent expert on global flu outbreaks with the University of Minnesota.
"We have no clue right now where we are between those two extremes. That's the problem," he said.
Health officials want to take every step to prevent an outbreak from spiraling into mass casualties. Predicting influenza is a dicey endeavor, with the U.S. government famously guessing wrong in 1976 about a swine flu pandemic that never materialized.
"The first lesson is anyone who tries to predict influenza often goes down in flames," said Dr. Richard Wenzel, the immediate past president of the International Society for Infectious Diseases.
But health officials are being asked to make such predictions, as panic began to set in over the weekend.
The epicenter was Mexico, where the virus is blamed for 86 deaths and an estimated 1,400 cases in the country since April 13. Schools were closed, church services canceled and Mexican President Felipe Calderon assumed new powers to isolate people infected with the swine flu virus.
International concern magnified as health officials across the world on Sunday said they were investigating suspected cases in people who traveled to Mexico and come back with flu-like illnesses. Among the nations reporting confirmed cases or investigations were Canada, France, Israel and New Zealand.
Meanwhile, in the United States, there were no deaths and all patients had either recovered or were recovering. But the confirmed cases around the nation rose from eight on Saturday morning to 20 by Sunday afternoon, including eight high school kids in New York City — a national media center. The New York Post's front page headline on Sunday was "Pig Flu Panic."
The concern level rose even more when federal officials on Sunday declared a public health emergency — a procedural step, they said, to mobilize antiviral medicine and other resources and be ready if the U.S. situation gets worse.
U.S. Centers for Disease Control and Prevention officials say that so far swine flu cases in this country have been mild. But they also say more cases are likely to be reported, at least partly because doctors and health officials across the country are looking intensively for suspicious cases.
And, troublingly, more severe cases are also likely, said Dr. Richard Besser, the CDC's acting director, in a Sunday news conference.
"As we continue to look for cases, we are going to see a broader spectrum of disease," he predicted. "We're going to see more severe disease in this country."
Besser also repeated what health officials have said since the beginning — they don't understand why the illnesses in Mexico have been more numerous and severe than in the United States. In fact, it's not even certain that new infections are occurring. The numbers could be rising simply because everyone's on the lookout.
He also said comparison to past pandemics are difficult.
"Every outbreak is unique," Besser said.
The new virus is called a swine flu, though it contains genetic segments from humans and birds viruses as well as from pigs from North America, Europe and Asia. Health officials had seen combinations of bird, pig and human virus before — but never such an intercontinental mix, including more than one pig virus.
More disturbing, this virus seems to spread among people more easily than past swine flus that have sometimes jumped from pigs to people.
There's a historical cause for people to worry.
Flu pandemics have been occurring with some regularity since at least the 1500s, but the frame of reference for health officials is the catastrophe of 1918-19. That one killed an estimated 20 to 50 million people worldwide.
Disease testing and tracking were far less sophisticated then, but the virus appeared in humans and pigs at about the same time and it was known as both Spanish flu and swine flu. Experts since then have said the deadly germ actually originated in birds.
But pigs may have made it worse. That pandemic began with a wave of mild illness that hit in the spring of 1918, followed by a far deadlier wave in the fall which was most lethal to young, healthy adults. Scientists have speculated that something happened to the virus after the first wave — one theory held that it infected pigs or other animals and mutated there — before revisiting humans in a deadlier form.
Pigs are considered particularly susceptible to both bird and human viruses and a likely place where the kind of genetic reassortment can take place that might lead to a new form of deadly, easily spread flu, scientists believe.
Such concern triggered public health alarm in 1976, when soldiers at Fort Dix, N.J., became sick with an unusual form of swine flu.
Federal officials vaccinated 40 million Americans. The pandemic never materialized, but thousands who got the shots filed injury claims, saying they suffered a paralyzing condition and other side effects from the vaccinations.
To this day, health officials don't know why the 1976 virus petered out.
Flu shots have been offered in the United States since the 1940s, but new types of flu viruses have remained a threat. Global outbreaks occurred again in 1957 and 1968, though the main victims were the elderly and chronically ill.
In the last several years, experts have been focused on a form of bird flu that was first reported in Asia. It's a highly deadly strain that has killed more than 250 people worldwide since 2003. Health officials around the world have taken steps to prepare for the possibility of that becoming a global outbreak, but to date that virus has not gained the ability to spread easily from person to person.