Is swine flu 'the big one' or a flu that fizzles?

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.

What is swine flu?
Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza viruses that causes regular outbreaks in pigs. People do not normally get swine flu, but human infections can and do happen. Swine flu viruses have been reported to spread from person-to-person, but in the past, this transmission was limited and not sustained beyond three people.

Are there human infections with swine flu in the U.S.?
In late March and early April 2009, cases of human infection with swine influenza A (H1N1) viruses were first reported in Southern California and near San Antonio, Texas. Other U.S. states have reported cases of swine flu infection in humans and cases have been reported internationally as well. An updated case count of confirmed swine flu infections in the United States is kept at http://www.cdc.gov/swineflu/investigation.htm CDC and local and state health agencies are working together to investigate this situation.

Is this swine flu virus contagious?
CDC has determined that this swine influenza A (H1N1) virus is contagious and is spreading from human to human. However, at this time, it not known how easily the virus spreads between people.

What are the signs and symptoms of swine flu in people?
The symptoms of swine flu in people are similar to the symptoms of regular human flu and include fever, cough, sore throat, body aches, headache, chills and fatigue. Some people have reported diarrhea and vomiting associated with swine flu. In the past, severe illness (pneumonia and respiratory failure) and deaths have been reported with swine flu infection in people. Like seasonal flu, swine flu may cause a worsening of underlying chronic medical conditions.

How does swine flu spread?
Spread of this swine influenza A (H1N1) virus is thought to be happening in the same way that seasonal flu spreads. Flu viruses are spread mainly from person to person through coughing or sneezing of people with influenza. Sometimes people may become infected by touching something with flu viruses on it and then touching their mouth or nose.

How can someone with the flu infect someone else?
Infected people may be able to infect others beginning 1 day before symptoms develop and up to 7 or more days after becoming sick. That means that you may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick.

What should I do to keep from getting the flu?
First and most important: wash your hands. Try to stay in good general health. Get plenty of sleep, be physically active, manage your stress, drink plenty of fluids, and eat nutritious food. Try not touch surfaces that may be contaminated with the flu virus. Avoid close contact with people who are sick.

Are there medicines to treat swine flu?
Yes. CDC recommends the use of oseltamivir or zanamivir for the treatment and/or prevention of infection with these swine influenza viruses. Antiviral drugs are prescription medicines (pills, liquid or an inhaler) that fight against the flu by keeping flu viruses from reproducing in your body. If you get sick, antiviral drugs can make your illness milder and make you feel better faster. They may also prevent serious flu complications. For treatment, antiviral drugs work best if started soon after getting sick (within 2 days of symptoms).

How long can an infected person spread swine flu to others?
People with swine influenza virus infection should be considered potentially contagious as long as they are symptomatic and possible for up to 7 days following illness onset. Children, especially younger children, might potentially be contagious for longer periods.

What surfaces are most likely to be sources of contamination?
Germs can be spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose, or mouth. Droplets from a cough or sneeze of an infected person move through the air. Germs can be spread when a person touches respiratory droplets from another person on a surface like a desk and then touches their own eyes, mouth or nose before washing their hands.

How long can viruses live outside the body?
We know that some viruses and bacteria can live 2 hours or longer on surfaces like cafeteria tables, doorknobs, and desks. Frequent handwashing will help you reduce the chance of getting contamination from these common surfaces.

What can I do to protect myself from getting sick?
There is no vaccine available right now to protect against swine flu. There are everyday actions that can help prevent the spread of germs that cause respiratory illnesses like influenza. Take these everyday steps to protect your health:

* Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
* Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hand cleaners are also effective.
* Avoid touching your eyes, nose or mouth. Germs spread this way.
* Try to avoid close contact with sick people.
* If you get sick with influenza, CDC recommends that you stay home from work or school and limit contact with others to keep from infecting them.

What is the best way to keep from spreading the virus through coughing or sneezing?
If you are sick, limit your contact with other people as much as possible. Do not go to work or school if ill. Cover your mouth and nose with a tissue when coughing or sneezing. It may prevent those around you from getting sick. Put your used tissue in the waste basket. Cover your cough or sneeze if you do not have a tissue. Then, clean your hands, and do so every time you cough or sneeze.

What is the best way to keep from spreading the virus through coughing or sneezing?
If you are sick, limit your contact with other people as much as possible. Do not go to work or school if ill. Cover your mouth and nose with a tissue when coughing or sneezing. It may prevent those around you from getting sick. Put your used tissue in the waste basket. Cover your cough or sneeze if you do not have a tissue. Then, clean your hands, and do so every time you cough or sneeze.

What is the best technique for washing my hands to avoid getting the flu?
Washing your hands often will help protect you from germs. Wash with soap and water. or clean with alcohol-based hand cleaner. we recommend that when you wash your hands -- with soap and warm water -- that you wash for 15 to 20 seconds. When soap and water are not available, alcohol-based disposable hand wipes or gel sanitizers may be used. You can find them in most supermarkets and drugstores. If using gel, rub your hands until the gel is dry. The gel doesn't need water to work; the alcohol in it kills the germs on your hands.

What should I do if I get sick?
If you live in areas where swine influenza cases have been identified and become ill with influenza-like symptoms, including fever, body aches, runny nose, sore throat, nausea, or vomiting or diarrhea, you may want to contact their health care provider, particularly if you are worried about your symptoms. Your health care provider will determine whether influenza testing or treatment is needed.

If you are sick, you should stay home and avoid contact with other people as much as possible to keep from spreading your illness to others.

If you become ill and experience any of the following warning signs, seek emergency medical care.

In children emergency warning signs that need urgent medical attention include:

* Fast breathing or trouble breathing
* Bluish skin color
* Not drinking enough fluids
* Not waking up or not interacting
* Being so irritable that the child does not want to be held
* Flu-like symptoms improve but then return with fever and worse cough
* Fever with a rash

In adults, emergency warning signs that need urgent medical attention include:

* Difficulty breathing or shortness of breath
* Pain or pressure in the chest or abdomen
* Sudden dizziness
* Confusion
* Severe or persistent vomiting

How serious is swine flu infection?
Like seasonal flu, swine flu in humans can vary in severity from mild to severe. Between 2005 until January 2009, 12 human cases of swine flu were detected in the U.S. with no deaths occurring. However, swine flu infection can be serious. In September 1988, a previously healthy 32-year-old pregnant woman in Wisconsin was hospitalized for pneumonia after being infected with swine flu and died 8 days later. A swine flu outbreak in Fort Dix, New Jersey occurred in 1976 that caused more than 200 cases with serious illness in several people and one death.

Can I get swine influenza from eating or preparing pork?
No. Swine influenza viruses are not spread by food. You cannot get swine influenza from eating pork or pork products. Eating properly handled and cooked pork products is safe.