Friday, October 30, 2009

Swine Whine

Influenza is an epidemic. It always has been. Each year several strains sweep through the globe infecting millions and killing hundreds of thousands. And up until now, we thought we had a small handle on these viruses. But now we have the swine flu, or H1N1, and it has not behaved as the usual influenza viruses usually behave. Because of that, it will cause devastation on many levels.

As a little background, there are three classes of influenza—A, B, and C. Influenza viruses are then classified by two proteins they carry on their outer coat—hemagluttinin and neuraminidase, or H and N. These proteins vary from strain to strain. Thus, you can have an H5N1 influenza virus, an H2N2 virus, and so on and so on. Strains can then further be classified based on their location of origin and year of outbreak. Thus, you can have a B/New Jersey/1977/H2N2 influenza strain. That particular strain does not exist, but you get the point. Influenza viruses also tend to spread in waves over time, much as locusts and cicadas do. It is because of this that we are able to make educated predictions about the coming year’s influenza viruses and create vaccines against them. Thus, vaccines are only effective for the year they are administered, as the strains for the next year are different.

While the swine flu has gotten a tremendous amount of media coverage, which is good for awareness, it has also unfortunately become an epidemic of misunderstanding in itself. To start, the initial scare was the name “swine flu”. Ever since the close overlap of the deadly SARS and avian flu, people have become wary of any disease originating from animals. Now the media uses the correct term of H1N1, but far too late. The term “swine flu” is here to stay. There has also been very few attempts to educate people to the fact the H1N1 is in fact just another influenza virus, and that getting H1N1 is just like getting the flu. What has made people worried is that H1N1 behaves differently than the usual influenza viruses in that it came far earlier than “flu season”, likely will not have a “season” at all, and prefers to attack younger healthier people. But because of the preexisting heightened fear of “swine flu”, all the cases of it seem more extreme and deadly. For example, the regular flu typically attacks the elderly, and so seeing five seniors in the ICU on ventilators is not surprising. But because of the predilection of H1N1 for young people and pregnant women, seeing five pregnant women in the ICU on ventilators is very surprising. Not because it’s the “swine flu”, but because we are not used to seeing five pregnant women in the ICU on ventilators. We misplace our disturbance of the scenario on virulence of H1N1 instead of on the unexpected demographics of the scenario.

H1N1 also seems far deadlier than the regular flu because we are not vaccinated against it as we typically are for the regular flu. Given that “flu season” usually runs from October to February, the vast majority of vaccinations are carried out in October and November. What that does is prevent a substantial number of people from getting the flu, but more importantly, removes the subsequent transmission of the flu by the vaccinated should they have contracted the flu if they were not vaccinated. That is, of course, the true power of vaccination. The H1N1 flu, however, has no true “season”. Thus, there was no lead time for the production of vaccine. That also means that people who contract H1N1 can spread to many more susceptible unvaccinated people, who can then propagate the epidemic. This is also why H1N1 seems deadlier than the regular flu—it has had more lead time to spread exponentially.

But now we have a vaccine for H1N1. So can we still make headway in limiting the epidemic? The CDC hopes so, but it may be too little too late as some say. I believe it will stem the epidemic, but not enough to change the way H1N1 is remembered. There are two large limitations with the H1N1 vaccine. First, there is not enough to vaccine the millions that should still be vaccinated. If you cannot vaccinate people, you cannot slow the exponential exposure of people to the virus. Second, because of the recent unsubstantiated scare of autism and MMR vaccines, as well as the painful memory of Guillain-Barre Syndrome in old school flu vaccines, people have convinced themselves not to vaccinate even if the vaccine is available to them. (Guillain-Barre Syndrome is a paralyzing neurologic disorder which occurred because of an autoimmune reaction to the influenza vaccine due to its manufacturing method, which is no longer used to create influenza vaccines) These two problems destroy the very foundation by which vaccination works to prevent an epidemic—prevent the exponential cycle of contracting and spreading the virus.

It gets worse. Just as people believe washing their hands for six seconds is enough (must be fifteen seconds), they also believe that wearing a mask will protect them from H1N1. That mask is the N95 respirator mask. The short story is that the N95 mask was designed to filter the smallest of the smallest particulate matter, keeping harmful organisms from being inhaled by the wearer. It is most commonly used by healthcare workers during treatment of patients with pulmonary tuberculosis. It is now most commonly used during treatment of H1N1 patients to block contraction of the virus. The fact that the mask is able to filter out such small organisms is a credit to its material and construction. But that means a good seal of the mask on the face of the wearer is required to reap that protection. After all, if you put on the mask and it does not sit properly along your cheek, how protected are you then? Because of this, healthcare workers are tested for correct use and fitting of the N95 mask with a taste test. You put on the mask, and then a hood like apparatus. A solution of saccharin or bitter compound is then aerosolized into the hood (so the tester is not subjected to the taste). If you taste the compound, whether it be sweet or bitter, you do not have the N95 mask on correctly. That is how good the N95 mask is at filtering out particulate matter.

Now take this common hospital scenario. You have a patient with H1N1. They are sick enough to be in the hospital. They have lots of family members visiting all the time. And because of the severity of illness they are in the hospital for five to seven days. The questions that is begged is do all these people wear masks when they visit and are they putting the masks on correctly? The answers are yes and no, respectively. The likelihood is slim that they are wearing the masks correctly. After all, the fit test is a time and resource heavy process. Not many healthcare workers are fit tested, so you could count on your third hand how many visitors are fit tested. So they end up using lots of masks over the hospital course of the patient, each at almost two dollars a piece. With the number of H1N1 cases rising, that will be a tremendous cost the hospitals and the healthcare system. And that’s not even the concerning problem. The concerning part is that by donning their incorrectly fitted masks they believe that they are protected from H1N1. You might as well given them aluminum foil hats to keep the aliens from stealing their thoughts.

But vaccination is like a religion. It is resistant to scientific data and logic. You have little chance of convincing people to get vaccinated with fancy diagrams and scary numbers. You need a smooth talking charismatic icon like a celebrity they will follow. It worked for voting, and it would work for vaccination. I can see it now—Rock the Vaccine.