Silent No More

Has the world gone crazy? Is Swine Flu the pandemic we've all been anticipating, dreading and shoring our defenses against? Have public officials far and wide lost their collective marbles, closing schools and making off the cuff remarks about keeping out of crowded, confined spaces? What DO we know? Perhaps more importantly, what do we NOT know?

I ain't nobody and we all know that. I'm just a girl with a long history of collecting information to explain and predict disease occurrence in populations. I have no public health authority but I do have what I've always had: a strong ability to seperate facts from conjecture, a bias toward science tempered with a respect for the responsibilities of the elected public officials who are responsible for the security of their communities.

This has been a ridiculous week in the media. In my estimation, its also been a bit ridiculous in public health circles but I understand the differing motivations operating there and I can live with it. I've heard "medical authorities", "licensed physicians" say that this epidemic of flu is nothing more than typical seasonal flu. Not true---its a novel human pathogen having "jumped" from piggies to their very intimate human friends. It is also occurring in mid- to late-Spring which is explicitly atypical in this hemisphere and may in fact be the most important feature to focus on in controlling the outbreak. Finally, WHO has escalated its pandemic potential by asserting that the virus can be transmitted from person to person. These are things we know.

I don't think there has been enough time for science to answer some critical questions:
1. What precisely is the severity of illness---what, exactly, is the Case-Fatality Ratio? Does the severity of illness and of outcome vary between persons who have been infected from sick piggies and those who have contracted the illness from another human...etc through each generation of disease transmission.
2. Has WHO's assertion of person to person transmission been made persuasively or have they been pushed to escalate because of circumstances and a lack of science rather than having conclusive evidence?

Just a few years ago we found ourselves handed the challenge of avian influenza. Our public health resources were mobilized and readied for action should cases emerge in this hemisphere...the epidemic cycle ramping up on the other side of the world gave us the benefit of much learning time. We knew with reasonable certainty there was no person to person transmission going on which is to be greatly hoped for in this instance. We knew that infected individuals had very specific travel histories and very specific contacts. That virus also had a very high fatality ratio. In terms of pandemic potential, it was of moderate concern: it represented an entirely new human pathogen meaning that our immune systems (and vaccines) would be quite ineffectual. The very interesting characteristic of the 1918 pandemic which is always referred to is its mechanism of death: the findings in all available samples indicate that the persons most likely to suffer most were those people with the most aggressive (healthy) immune response---this is very much what we must be wary of with all novel pathogens: that it will decimate the young and healthy; inverting classical mortality curves. This has not been seen, neither with H5N1 several years ago or with the currently circulating strain.

If I were asked to advise my Health Officer as I have often been called upon to do I would tell her:

• 1. The epicenter of the outbreak is very well defined outside of our jurisdiction. Officials there have made all the appropriate control measures and are working with vigilance and exceptionally qualified scientists and health officials of all kinds.
• 2. The surveillance potential for illnesses coming into our jurisdiction is high: flu cases in non-flu season will be easily recognized and should be singled out for greater clinical and epidemiologic study. We have the resources for these operations prepared and in place.
  
• 3. The risk of sporadic cases turning up here is close to nil but in fact, its not nil: we've several cases that appear related on our plates.
• 4. Public concern is high. Partly becuase we've asked the public to be very concerned about the potential for an influenza emergency and this is a very important objective to be maintained.
• 5. In my fairly well qualified opinion, this is not the flu outbreak that we've been fearing.
• 6. Public health officials and elected officials must balance the fear of the public against the need for continuity of operations. Some action is, in fact, required. I think that response would vary depending upon proximity to the epicenter, travel patterns of residents, etc.

For my friends and family, I will be watchful and perhaps a teeny bit more cautious about sniffles accompanied by fever. I will hope we all practice appropriate cough/sneeze containment. And for the time being, I'm thinking I'll avoid any non-professional travel to Mexico City. I shall continue to refrain from kissing pigs and/or chickens.