I thought it might be a good idea to write my weekly post early this week since there is so much anxiety about swine flu.

The media and officials in many countries have contributed to much fear and misunderstanding which may turn out to be more harmful than swine flu itself.  Let me try to shed some light without raising the heat.

The swine flu virus has been around for a long time as a cause of respiratory illness in pigs.  Sporadically, it has caused illness in humans who had a lot of contacts with pigs.  What’s unusual now and causing concern is that the swine flu virus for the first time has recently evolved the ability to be transmitted from person to person.  (By the way, though unfortunate, this is a beautiful demonstration of evolution happening before our eyes.  Yay, Darwin!)  The swine flu that is currently infecting humans is a blend of genes from the avian flu, the human flu and the swine flu.  Not surprisingly, given its makeup, it causes an illness in humans just like the flu.  Meaning (human) patients with the swine flu have fever, muscle aches, a cough and sore throat, just like a regular flu.

At this point the attentive reader is asking “But the swine flu must be worse than the regular flu, otherwise, why the big kerfuffle?”  Nope.  There is no reason to believe that the swine flu causes an illness worse than the regular flu.  As of today, 40 cases have been identified in the US.  There have been no fatalities and only one hospitalization.  All of the patients have recovered.

“So why the hubbub?”

Well, what makes this unusual and to public health officials potentially worrisome is that there is a new virus that can spread from human to human and it has about 6.7 billion potential hosts to infect that don’t have immunity for it.  Old viruses, like measles or chicken pox, can cause a little outbreak here or there, but most people are immune either due to vaccination or because they already had the disease.  Other old viruses like the regular flu or cold viruses constantly change, so they can infect new people all the time, but there’s still only a limited population that hasn’t been exposed to the current strain.  What’s different now is that, depending on the rate of spread of this virus, we might all catch it at about the same time.  That’s not a big deal for most of us.  Again, the illness won’t be worse than a regular flu.  But imagine if even a quarter of the 3.8 million people in Los Angeles had the flu at the same time.  The consequences for the vast majority of individuals would be just a major inconvenience, but for the frailest among us, and for public health and safety services, it would be catastrophic.

“But what about all the fatalities in Mexico?  Those numbers sound a lot worse than a regular flu.”

There have been some fatalities from respiratory illnesses in Mexico.  Some of them have not been confirmed to be from the swine flu, but some have.  Some of the apparent difference in severity between the cases in the US and the cases in Mexico has to do with the very aggressive surveillance and tracking being done by the CDC in the US.  The CDC is aggressively trying to find as many cases as possible in the US, so the 40 cases that we know about are the result of those efforts.  In Mexico there’s no way to know how many cases there have been.  Some of the cases only came to the attention of public health officials because they were fatalities.  So Mexico may have had thousands or tens of thousands of undiagnosed cases which recovered without treatment, and dozens of fatalities which were noticed.  Just like a regular flu season.  (Statisticians call this a sampling error – an apparent difference between two groups when no actual difference exists caused by sampling the two groups differently.)

“But won’t the swine flu get more lethal as it mutates?”

There’s no way to tell how the swine flu will change in the future, but what we know about previous epidemics suggests that it won’t get more lethal.  A mutation that makes the virus more quickly incapacitating and lethal is unlikely to be passed on to other hosts.  On the other hand a mutation that makes the disease milder so that the host goes to work, doesn’t feel so bad, and coughs all over his coworkers for the next two weeks before recovering will infect a lot more people.  That’s why in general epidemics get milder as time goes on, not more severe.

“I’ve been avoiding eating pork.”

That might be good for your cholesterol, but you can’t get swine flu from eating pork.  It’s transmitted from person to person, like the regular flu.

“What do I do if I get sick?”

If you develop flu symptoms, don’t go to work.  Cover your cough.  Call or see your doctor right away, since the same anti-viral medicines that shorten the duration of the regular flu work for the swine flu also.

“So I should call my doctor now, and demand a prescription for anti-viral medicine just to have around in case I get sick later?”

No.  You should not get anti-viral medicine unless you are sick.  We will not run out of anti-viral medicine.  By the way, what happened to that Cipro you forced me to prescribe for you back in 2001 because you were worried about anthrax?

“I still have that.  It’s got cobwebs on it.  Is there anything I can do to avoid getting sick?”

Avoid sick people.  Wash your hands frequently.

“So we’re not all doomed?”

No.  The world will not end because of the swine flu.

“But what about the coming zombie apocalypse?”

Well!  Look at the time!  Gotta go.

Learn more:

The Centers for Disease Control and Prevention swine flu information page

Today’s press briefing from the Centers for Disease Control and Prevention

Do your homework about zombies before it’s too late