My kid's pediatrician just sent me this. It makes the ridiculousness of all this news coverage very plain:
For those of you who were around in 1976, it must feel like deja vu all over again - the swine flu is back! But is it really such a big deal?
SEASONAL INFLUENZA
OK, let's lay down some foundation information first. Influenza is a virus. It is a common cause of acute respiratory infections, mostly in the fall, winter, and early spring. Typical symptoms of influenza include fever, cough, body aches, sore throat, headache, chills, and fatigue. While most people recover without harm, influenza does lead to many hospitalizations for pneumonia and dehydration. Severe infections, hospitalizations, and deaths occur most commonly in young children, the elderly, and those with weakened immune systems. Influenza causes more than 35,000 deaths in the US every year, about 100 of those in previously healthy kids (3 in Michigan in 2009). Let's call this "seasonal influenza".
TRANSMISSIBILITY/INFECTIVITY AND VIRULENCE
Each influenza virus has a level of ability to be transmitted from host to host (tranmissibility) and to infect a host (infectivity). Each virus also has a certain level of ability to cause severe symptoms and complications (virulence). For brevity sake, I'll call it TIV when I lump these three together.
GOOD YEARS AND NOT SO GOOD YEARS
Seasonal influenza occurs every year. Very tiny changes in the genetics of the influenza virus determine whether we perceive the season as a "good year" or a "not so good year". However, the rate of infection and severe complications (pneumonia, hospitalization, death) stay within a relatively narrow frequency because the TIV do not change much.
BAD YEARS
About every 5-10 years, a more significant genetic change occurs, increasing the TIV of the "seasonal influenza" a little more. Thus, there will be more total infections and they will seem longer and more severe and there will be a modest increase in episodes of severe complications. But you ain't seen nothing yet!
WHERE ARE THE SWINE?
Typically, influenza viruses are only able to infect certain species of animals. Influenza viruses are quite picky. Some strains of influenza infect only humans. Some infect only birds (think avian flu). And some only pigs (there's the swine!). Other mammals may get influenza but at a much lower frequency and severity. So let's focus on the big three - humans, birds, and pigs.
SWAPPING DNA AND VACCINES
An influenza virus specific to one of the big three species typically can not be transmitted to an animal of any other species. And if it is, it may not cause any infection or symptoms.
However, influenza viruses routinely swap their DNA. Busy little buggars, they are! That's why we have to make a new influenza vaccine every year, to try to make sure it matches the expected new strains. Sometimes we guess the right strains and sometimes we don't. Even if we don't guess correctly, there is still often significant protection from the vaccine because the genetic changes are minor (see GOOD YEARS, NOT SO GOOD YEARS, and BAD YEARS above).
EPIDEMICS
Now here's where things get a little dicey! If a human influenza virus happens to swap DNA with an avian (bird) virus or a swine (pig) virus, the genetic change is much more significant. The resulting virus still has the ability to infect humans easily but also has the virulence to cause much more severe infections because our immune systems have never seen the avian or swine DNA before. Therefore, our immune response will be slower and weaker in attacking the new strain. These swaps are not common, happening about 3-4 times per century. The last one to occur was the Hong Kong flu in 1968. The virulence was rather low, though, so there was not an increase in the number of deaths. The one before that, the Asian flu in 1957, was more potent and the death number was about doubled. These infections were more spotty in the US and did not spread significantly throughout the world. These are called epidemics.
PANDEMICS
The big, bad granddaddy of influenza seasons that we all fear (and rightly so) was the Spanish flu in 1917-1918. That strain killed more than 700,000 in the US alone in one year. That's more deaths than for all countries in World War I combined. And the worldwide estimate was 50-100 million deaths. That's right, millions! An epidemic like this that sweeps throughout the world is called a pandemic.
ON THE LOOKOUT
Some people say that we are "overdue" for a pandemic. Not really. What has happened is that improved sanitation and improved health care in the past 90 years has made an epidemic or pandemic much less likely to occur. However, the ease of international travel has started to reverse that trend. That's why there has been such a concern with the avian flu strains from southeast Asia since 2001 (so far all strains have shown very low transmissibility and infectivity in humans) and now the Mexican swine strain. In two weeks from the first diagnosed and confirmed case in Mexico City, the virus has spread to six countries all across the globe.
TIME TO PANIC?!?!?!?!?
No, it is not time to panic! It is time to be concerned. It is time to let the experts around the world that follow influenza closely do their job. And it may be time to watch less sensationalized television and go play with your kids more! Although the Mexican swine strain has shown strong human-to-human transmissibility and infectivity, it has not yet shown significant virulence. All cases outside Mexico have been reported as milder than our average seasonal influenza case. And most of the deaths in Mexico have not been confirmed as being truly caused by the swine flu strain.
WHAT CAN WE DO!!!!
The best way to contain the Mexican swine flu outbreak is to use the same hygiene and common sense needed to contain the seasonal influenza.
1) If you have a fever or other symptoms of an acute respiratory infection that seem like more than a mild cold (cough, headache, sore throat, chills, body aches), DO NOT PASS GO! DO NOT COLLECT YOUR $200! What I really mean is STAY HOME. Don't go to work. Don't go to school. Don't go to church, or the mall, or to a friend's house, or a family reunion.
2) Avoid prolonged and/or close contact with people with the above symptoms.
3) Avoid touching your eyes, nose, or mouth.
4) Wash your hands frequently with soap and water. And, in between, use hand gel sanitizer. And clean all of those items and surfaces that you touch frequently (door knobs, faucets, phones, etc).
5) Cover you mouth when you cough and sneeze. If you use a tissue or handkerchief, wash your hands afterwards. Otherwise, cough and sneeze onto your forearm or elbow.
6) If you have the above symptoms, call your doctor.
AN HISTORICAL PERSPECTIVE
Swine Flu 1976: An Epidemic that wasn't; The treatment was worse than the disease.
So, OK, back to the swine flu "epidemic" of 1976. The US was developing a vaccine against that swine flu strain. The US government fast-tracked the development of the vaccine and ordered it's release and use against the recommendation of the researchers and medical community, who were not satisfied with its safety. The result - the swine flu strain was too weak to cause anything close to an epidemic (we had a very "routine" flu season) but many who received the vaccine were sickened severely and some died. This is why many people today still believe that the flu vaccine can cause flu symptoms or may be dangerous. Only true for this one vaccine.
That same fast track and release too early process occurred with the smallpox vaccine after 9/11. Fortunately, less people were sickened and there were only a handful of suspected deaths from the vaccine.
Point of interest - in both situations, the man who approved the premature release of the vaccine was the same person, Dick Cheney.