Swine Flu Q&A

ADVANCE: How is the World Health Organization doing as far as pandemic flu preparations with regard to the H1N1 virus?

Schmidt: It's really not so much an issue of how they're doing because they're reacting as the virus emerges. The World Health Organization, as a consequence of getting ready for an avian pandemic, has forced many nations to prepare. It's that preparation that took place over probably the last 4 or 5 years in many countries that has really served us well. If you think about it, we were quick to pick up on the emergence of the virus. This virus is behaving like a pandemic. It's moved around the globe relatively quickly. If you look back, it looks like it started in late March or early April.

The virus has an RNA polymerase that is error prone; that is, it makes mistakes or results in antigenic drift, and it is also capable of antigenic shift -- the transfer of genes from flu viruses grown in another species like pigs, chickens, ducks, humans (even your pets can combine with the another virus) -- resulting in a very different virus from the ones that initially co-infected the cell. In other words, the progeny virus infecting your cell has an opportunity to acquire new genes from other viruses getting together and having a party where they exchange, sort of like trading club partners, one gene from virus number one to virus number two. Because these things grow so quickly, they can really change how virulent they are.

Do you agree with the steps World Health Organization (WHO) officials have taken and the time frame in which they have taken them?

In terms to how quickly they have alerted us to the issues, yes. Whether or not they're calling it an epidemic or a pandemic, that's really an "inside baseball" issue where it's really for the epidemiologists to distinguish one from the other. From the general public's perspective and from the nation's perspective, the question is whether or not [individuals] are at risk of getting sick. With their timely warnings and testing, the WHO and CDC (Centers for Disease Control and Prevention) have helped the healthcare providers and laboratorians react to this emerging situation. The right folks are taking the lead, providing government leaders the facts they need to make informed decisions ordering vaccines. So I think that's why the director general, Dr. Margaret Chen, declared it a pandemic -- because it has satisfied the definition of pandemic, and we don't yet know what's going to happen to the virulence of this virus as it moves around the globe. Preparation is priceless.  

Can you talk briefly about the new H1N1 virus, how it is transmitted and steps to minimize spread?

The virus is transmitted identically to all common flu viruses that we have seen since man has been living in a domesticated sense. It's transmitted by fomites. That means it's a rather larger particle or droplet when you consider the size of the virus. So it comes in contact with surfaces, and then you acquire the virus off of the surface. Or should someone sneeze or cough on you, and you actually encounter it or inhale it, you become infected. The rule of thumb to protect yourself is if you keep everyone at arm's length and be diligent and rigorous with respect to hand, cough and sneeze hygiene, you will be well-served in protecting yourself. So if you follow the simple rules of hand hygiene -- washing your hands with soap and water or one of these alcohol-based gels before you interact with your mucous membranes, you will lessen your likelihood of contracting the virus.

Can you talk about screening for the virus? I read on the FDA's site that it had approved the rRT-PCR Swine Flu Panel diagnostic test for emergency use, but has placed three manufacturers on its "Fraudulent H1N1 Influenza Products List" for marketing their tests without FDA approval.

The issue is about resources. If you're one of those individuals in a risk group -- principally diabetics seem to be at higher risk of developing severe disease, you want to be aware that you have the disease sooner. And the best way of typically diagnosing the flu is through clinical parameters. Influenza-like illness -- fever, aches and pains and mild nausea -- seem to be the best clinical indicators for rapid diagnosis from which you would then obtain a prescription from your healthcare provider to control the amplification of the virus, thereby limiting the severity and length of disease. The antivirals -- either zanamivir (Relenza) or oseltamivir (Tamiflu) -- are neuraminidase inhibitors, which limit the release of the viral progeny from the cell, thereby limiting the amplification of the virus, preventing it from taking over your lungs.

More and more, providers are relying on clinical indicators to prescribe these medications to the patient because of limited resources and time for the neuraminidase inhibitors (which need to be taken within in a limited window if they are going to be effective). The great thing about molecular diagnosis is that it's fast, but it's not as fast as good clinical judgment when it comes to effectively prescribing the use of antivirals. Thus, by the time the clinician would get the answer, it would be too late to prescribe [the antivirals] to the patient if a positive molecular test was their sole indicator for prescribing the antiviral therapy.  The sooner you take those antivirals, the better off you'll be.