How Swine Flu Works

Staying Healthy Image Gallery In some countries, face masks have become the ultimate back-to-school accessory. Get health tips with staying healthy pictures.
Associated Press/Vincent Thian

The weeks before heading back to school can be stressful for children. Will they like their new teachers and classmates? Do they have the right backpack or lunch box to fit in with the cool kids? How can they be expected to endure a long day of learning after a leisurely summer? And this year, kids and their parents have an additional worry: a possible spike in the rate of H1N1/2009 influenza, which is known by a variety of aliases but hasn't yet completely thrown off its original moniker of swine flu.

Worries about swine flu are nothing new; people have been concerned since the first case was found in a small town in Mexico in the spring of 2009. The fact that the rates of infection and death have held steady throughout the summer, a time in which cases of the flu usually drop off, is new, however. In June 2009, the World Health Organization (WHO) announced that the disease had reached global pandemic level, a distinction that refers to the spread of the condition, not its severity.


Kids have lived with the specter of swine flu throughout their time off at summer camps and swimming pools, but it's the return to school that has some public health officials worried. Not only are children well-known agents of infection when it comes to colds and flu, the timing coincides with the regular cold and flu season. In July 2009, the Centers for Disease Control and Prevention projected that 40 percent of Americans could contract swine flu in the next year, perhaps resulting in several hundred thousand deaths if a swine flu vaccine wasn't made available [source: Stobbe].

But to some, the fuss over swine flu is just much ado about nothing. Those who have had the disease report that it's nothing more than a mild flu, and while deaths have been reported, the casualties pale in comparison to the 36,000 Americans who die each year after suffering from seasonal flu [source: Ellenberg]. Sure, this strain of influenza may have a knockout combination of swine, avian and human influenza viruses that has never been seen before in humans, but the first wave didn't yield the damage that was once predicted. What's the big deal?

To understand why reactions to the 2009 H1N1 virus vary so widely, it's helpful to cast our eyes toward pandemics of years past.


Swine Flu History

When the first cases of a mysterious flu came to light in 2009, the disease was dubbed "swine flu." Now, researchers understand that we're dealing with a completely new monster of a virus, and historic instances of pandemic flu loom large in public health officials' minds. The scenario that no one wants to repeat is the deadly 1918 flu, sometimes called Spanish flu. This disease was also originally attributed to swine, though now the birds get the blame. Within a year, more than 50 million people died; 500,000 of those fatalities were in the United States alone [source: Beck].

It's still possible that the current H1N1 virus, though mild now, could mutate into a deadlier flu. However, just as the virus could develop into something much deadlier, it could also go the other way and become milder as it travels the world. If that happens, it would be something of a repeat of 1976, the last time swine flu broke out in the United States.


That year, two soldiers at Fort Dix came down with the flu, and one of the men died. Fearing another deadly epidemic, the government announced plans to vaccinate the entire country. However, the disease never spread beyond Fort Dix, and the vaccine, which was never explained well to the public, was linked to a paralyzing neuromuscular disorder known as Guillain-Barre syndrome [source: Di Justo]. It's understandable that people who remember the events of 1976 are wary of the panic surrounding the new pandemic. (Those who were vaccinated in 1976 should take note that they're not protected from the 2009 version of swine flu.)

Right now, no one knows whether the current virus will be immensely fatal or just a big fizzle. But there's one thing in particular about each of these outbreaks to note: In each case, the deaths occurred in people that we'd otherwise consider young and healthy. We tend to think of flu resulting in the deaths of the very old and the very young, and the pandemics did affect those age groups. But the soldier at Fort Dix was a young man likely in very good physical condition, and more than half of the serious cases of the 2009 swine flu have involved people aged 5 to 24. For that reason alone, we have reason to remain vigilant about H1N1. So what, exactly, are we supposed to be on the lookout for?


Swine Flu Symptoms and Diagnosis

A pregnant woman with swine flu symptoms receiving medical treatment in Argentina.
Associated Press/Pablo Barrera

Swine flu symptoms, which are very similar to seasonal flu symptoms, include fever, cough, sore throat, stuffy or runny nose, body aches, headache, chills and fatigue. Additionally, a bout of the swine flu is more likely to include gastrointestinal ills, such as diarrhea and vomiting, than a case of seasonal flu. Generally, most people who have had the swine flu recover in about a week without needing any hospitalization or medical treatment.

There are only a few laboratories in the world that can distinguish a case of swine flu from seasonal flu; doctors can send a throat or nose culture to the labs to confirm the virus but are only doing so for certain groups at high risk of complications. People with pre-existing conditions like asthma, diabetes and heart disease are at greater risk of requiring hospitalization, as these conditions can be exacerbated by swine flu. Children younger than 5 and adults older than 65 are a concern in any flu pandemic, but as we mentioned, the latter seem to be doing fairly well so far. Of most concern to doctors right now are pregnant women.


It's not risk to the fetus that's so troubling about pregnant women with H1N1 -- rather, women themselves are at risk as their pregnancy progresses. This may be because women have decreased lung capacity as their fetus grows, which makes it harder for them to breathe even without the respiratory attack brought on by swine flu [source: DeNoon]. Additionally, pregnant women might already be more susceptible to viral diseases thanks to changes in their immune systems. It's important for pregnant women to see their doctors as soon as they suspect a case of the swine flu; the cases that have ended in death so far have involved women who postponed treatment out of fear of starting medications during pregnancy [source: DeNoon].

While you don't need to see a doctor for a diagnosis of swine flu, there are a few complications to be on the lookout for, regardless of whether you belong to a high-risk group or not. You need urgent medical attention if you have trouble breathing, severe vomiting or pain in the chest or abdomen. Another red flag: if your symptoms abate only to come back more severely. Additionally, be on the lookout for potential neurological complications. In children, these complications may show up in the form of seizures, extreme irritability or memory problems; adults might experience sudden dizziness or confusion. These symptoms need immediate medical treatment. But what treatment can someone with swine flu expect, and how does one avoid getting infected in the first place?


How to Treat Swine Flu

Tamiflu, an antiviral medication that can reduce the duration and severity of swine flu, is in high demand.
Associated Press/Heribert Proepper

Any over-the-counter medication can be used to treat the symptoms of swine flu, but the true wonder drugs are the antivirals oseltamivir (also known as Tamiflu) and zanamivir (alias: Relenza). Oseltamivir and zanamivir have been shown to shorten the duration and severity of swine flu when taken within 48 hours after symptoms appear. These medications are only available by prescription, and due to limited supply, it's not a guarantee that everyone will have access to these drugs. If swine flu becomes extremely severe, doctors may have to save their doses for those most in need, a group that includes medical personnel, members of the military, children under 5 and pregnant women.

The antivirals are also 70 to 90 percent effective at preventing swine flu [source: Beam]. Pregnant women should talk to their doctors about taking antivirals to ward off swine flu, particularly if someone in their household becomes infected. In this scenario, the pregnant woman should not serve as the primary caregiver, nor should any other people at high risk for swine flu complications.


When one member of the family comes down with swine flu, he or she should essentially be quarantined to one room of the house, while everyone else should wash their hands religiously. Caregivers should be especially diligent with the hand-washing, and they may want to wear surgical face masks that fit tightly (as opposed to looser-fitting household cleaning masks). Caregivers should be careful when handling the sick person's laundry and not hug it to their bodies; surfaces in the home should be wiped down regularly with household disinfectants.

The seasonal flu vaccine will not provide protection from swine flu, but numerous drug companies are furiously at work on a swine flu vaccine that is expected to be available in the fall of 2009. As with the antivirals, doctors may need to prioritize who receives the vaccine at first. In the meantime, it's important to focus on prevention.


How to Prevent Swine Flu

A kindergartener in Hong Kong washes her hands before entering her classroom.
Associated Press/Kin Cheung

Swine flu is similar to seasonal flu in its method of transmission. It is spread from person to person (no swine is involved, so it's perfectly safe to eat pork) via the infected droplets from a cough or a sneeze. After an uncovered cough, the droplets of virus hang in the air, a phenomenon that happens more easily in winter, as a humid summer tends to weigh the droplets down so they fall. When the droplets do land, they are still infectious for up to eight hours [source: CDC].

To keep the infection from spreading, you should always cover your nose and mouth when you sneeze or cough, and throw any used tissues away immediately. Wash your hands with soap and water often; alcohol-based hand cleansers will also take care of the germs. Avoid touching your eyes, nose and mouth so that germy droplets left on objects and surfaces don't have a chance to get close. Most importantly, stay home if you're sick -- no work, no school, no errands, no trips other than the ones to your doctor. The CDC recommends staying home for seven days after your symptoms begin or until you have been symptom-free for 24 hours, whichever is longer.


While you may have only very mild symptoms, it's important to understand that the H1N1 virus might affect the people around you more intensely. You could go to work and infect a male co-worker; he might have mild symptoms as well, but the disease could be immensely dangerous to his pregnant wife. This is one of the reasons why swine flu parties, in which participants gather around someone with a mild form of the disease, are discouraged by public health organizations.

As we've mentioned, the 2009 H1N1 virus may remain mild, or it may become deadly. It's important to maintain a middle ground between panic and complacency. While no one needs to head to their underground bunker, use this as an opportunity to create or revise your family preparedness plan and readiness kit. Such a kit should contain a two-week supply of water, non-perishable food and health supplies.

For more on swine flu, see the links on the next page.


Lots More Information

Related HowStuffWorks Articles

  • Arnquist, Sarah. "Swine Flu May Cause Seizures in Children." New York Times. July 24, 2009. (Aug. 3, 2009)
  • Beam, Christopher. "Swine Flu FAQ." Slate. May 1, 2009. (Aug. 3, 2009)
  • Beck, Melinda. "Seeking Lessons From the Past to Fight Flu." Wall Street Journal. April 28, 2009. (Aug. 3, 2009)
  • Bradsher, Keith. "The Naming of Swine Flu, a Curious Matter." New York Times. April 29, 2009. (Aug. 3, 2009)
  • Centers for Disease Control and Prevention. "Novel H1N1 Flu (Swine Flu)." (Aug. 3, 2009)
  • Cohen, Jon. "Do Surgical Masks Stop Swine Flu?" Slate. April 27, 2009. (Aug. 3, 2009)
  • Davey, Monica. "Thousands Face a Balancing Act Over Flu Fears." New York Times. May 1, 2009. (Aug. 3, 2009)
  • DeNoon, Daniel J. "Pregnany Raises Swine Flu Death Risk." WebMD. July 29, 2009. (Aug. 3, 2009)
  • DeNoon, Daniel J. "Swine Flu Pandemic FAQ." WebMD. (Aug. 3, 2009)
  • DeNoon, Daniel J. "Swine Flu FAQ." WebMD. (Aug. 3, 2009)
  • DeNoon, Daniel J. "Swine Flu Less Severe for Over-50s?" WebMD. May 20, 2009. (Aug. 3, 2009)
  • DeNoon, Daniel J. "Swine Flu (H1N1) and Face Masks." WebMD. (Aug. 3, 2009)
  • DeNoon, Daniel J. "Swine Flu Vaccine: When?" July 20, 2009. (Aug. 3, 2009)
  • DeNoon, Daniel J. "WHO Declares Swine Flu Pandemic." June 11, 2009. (Aug. 3, 2009)
  • Di Justo, Patrick. "The Last Great Swine Flu Epidemic." Salon. April 28, 2009. (Aug. 3, 2009)
  • Ellenberg, Jordan. "Influenza Body Count." Slate. May 14, 2009. (Aug. 3, 2009)
  • "Flu Special Report: The Basics." LiveScience. April 26, 2009. (Aug. 3, 2009)
  • Goodier, Robert. "Innards of H1N1 Virus Resemble 'Flu Sausage.'" Live Science. May 21, 2009. (Aug. 3, 2009)
  • Grady, Denise. "Swine Flu Plan Would Put Some Ahead for Vaccine." New York Times. July 30, 2009. (Aug. 3, 2009)
  • "H1N1 Flu Virus (Swine Flu)." WebMD. (Aug. 3, 2009)
  • Hitti, Miranda. "Putting Swine Flu in Perspective." WebMD. May 1, 2009. (Aug. 3, 2009)
  • Hitti, Miranda. "Swine Flu: 10 Things Not to Do." WebMD. (Aug. 3, 2009)
  • Lloyd, Robin. "Is Swine Flu Pandemic Imminent?" LiveScience. April 28, 2009. (Aug. 3, 2009)
  • Lloyd, Robin. "Q&A: Swine Flu Myths and Mysteries." LiveScience. April 27, 2009. (Aug. 3, 2009)
  • MacKenzie, Debora. "Revealed: How pandemic swine flu kills." New Scientist. July 3, 2009. (Aug. 3, 2009)
  • MacKenzie, Debora. "Swine flu: Can science save us from the second wave?" New Scientist. May 6, 2009. (Aug. 3, 2009)
  • MacKenzie, Debora. "Swine flu: What you need to know." New Scientist. May 27, 2009. (Aug. 3, 2009)
  • McNeil, Donald G., Jr. "Debating the Wisdom of 'Swine Flu Parties.'" New York Times. May 7, 2009. (Aug. 3, 2009)
  • McNeil, Donald G., Jr. "Other Illnesses May Precede Worst Cases of Swine Flu." May 9, 2009. (Aug. 3, 2009)
  • McNeil, Donald G., Jr. "Swine Flu Expected to Return With Opening of School." New York Times. July 18, 2009. (Aug. 3, 2009)
  • McNeil, Donald G., Jr. "U.S. Declares Public Health Emergency Over Swine Flu." New York Times. April 27, 2009. (Aug. 3, 2009)
  • "Prioritize Pregnant Women to Get Swine Flu Shot, Experts Say." HealthDay. July 29, 2009. (Aug. 3, 2009)
  • Reinberg, Steven. "Why Swine Flu Differs from Seasonal Flu." HealthDay. July 2, 2009. (Aug. 3, 2009)
  • Stobbe, Mike. "Swine Flu Could Hit 40 Percent in United States." Time. July 25, 2009. (Aug. 3, 2009),8599,1912816,00.html
  • "Swine Flu (H1N1 Flu)." Mayo Clinic. July 31, 2009. (Aug. 3, 2009)
  • "Swine Flu More Severe than Seasonal Flu." LiveScience. July 14, 2009. (Aug. 3, 2009)
  • Walsh, Bryan. "How to Prepare for a Pandemic." Time. May 18, 2009. (Aug. 3, 2009),9171,1896728,00.html
  • Walsh, Bryan. "Think H1N1 is Bad Now? Wait Till Flu Season." Time. July 22, 2009. (Aug. 3, 2009),8599,1912087,00.html
  • Walsh, Bryan. "Top 5 Swine Flu Don'ts." Time. May 1, 2009. (Aug. 3, 2009),8599,1895216,00.html
  • World Health Organization. "Pandemic (H1N1) 2009." (Aug. 3, 2009)