"It seems that the influenza virus' ability to survive and be transmitted person-to-person is greatly affected by how dry or wet the air is," says Jeffrey Shaman, Ph.D., an atmospheric scientist at Oregon State University in Corvallis, who specializes in ties between climate and disease transmission, and a co-author of the new study.
This introduces a whole new world of research possibilities that are just fresh out of the gate. I encourage any of you or your students to investigate, including:
(1) Cross-referencing spread of the H1N1 outbreak with April daily humidity data in Mexico, New York, Texas and California: what patterns or indications might this reveal?
(2) Comparing that data to climate norms: Was it more or less humid than normal at onset? Could this have influenced the March-to-April outbreak phase in Mexico?
(3) Real-time tracking of current humidity and temperature data as compared to spread of the virus in the Maryland or the eastern U.S. Has our recent washout slowed progress of the virus?
(4) Historical analysis of temp/humidity data in the fall of 1918: Did this influence velocity of the lethal second wave that swept the globe in two months (when trans-Atlantic travel alone took a week or more?) For a glimpse at early research on this very idea, review a 1923 report by the Canadian Medical Association Journal. Now that's what I call back in the day.
The organizing question going forward would be: Could weather data be used to predict how a reassorted virus might spread in a second wave this fall? Things that make you go hmmm....
TUE 5 MAY - 10:00 pm. A sigh of relief is heard across the country as the CDC issues updated interim guidance on K-12 school closures. It would appear that while the virus remains high transmissible, it has a low infectivity rate, which is the technical way of saying: "Not everyone who gets exposed will get sick." There is much good news from this development, but health officials at the CDC and WHO remain very cautious about what may come this fall. It's just as important to recognize that Mother Nature has given the entire world a full dress rehearsal for how we might react in a severe pandemic. This is not to suggest the suffering of those whom lost loved ones is merely a statistic in order to better our lives through their pain.
On the contrary, all societies will stand to benefit from the volumes of knowledge disease researchers have gained the past few weeks. That knowledge will go on to save and improve lives this fall and beyond should H1N1 reassort in the southern hemisphere or elsewhere. All those who fell ill or passed away in this outbreak did not do so in vain. Their "involuntary participation" in an startlingly-fast influenza epidemic will serve the greater good of all humanity for a long time to come. The unfortunate news is that for public health professionals and governments alike, the real surveillance period has just begun. We're still at WHO Phase 5, signaling that a pandemic is imminent, and it may be some time before that backs down. In preparation for that day, the gathering of research continues.
Over the next week, the majority of flu monitoring links on this site will be transferred to a new website titled "Foot's Flucast" complete with it's own URL. From there you will continue to have quick glance access to the latest auto-updating features in order to track the H1N1 situation in the US and around the world. On-going research about this virus and the mitigation strategies for a secondary outbreaks will remain priority topics on that site.
To the many faithful readers, please accept my thanks and appreciation for your patience during this whip-lash of a topic shift from weather to influenza. I'm sure many of you are suffering from "flu fatigue" by now, and would welcome back the good old days of simply tracking hurricanes. That time will be here soon enough my friend, soon enough.
SAT MAY 2 - 7:00 AM. (Updated 5/3/09) Whether this virus produces a pandemic occurs or not, the genetic material of 2009 H1N1 will eventually join the flu cocktails that routinely traverse the globe during seasonal influenza. While it may be good news in the short term that this flu causes just "mild cases," some infectious disease experts such as Dr. Michael Osterholm from the University of Minnesota view that data in a different light. Consider listening to this 4/30/09 interiew with him conducted by Minnesota Public Radio.
The unnerving part of how this virus performs is very similar to what happened in the spring and summer of 1918. You might cry foul with that idea, claiming: "What about technology and advances in modern medicine, surely we can do better than relying on data almost a century old?" To that I would respond by echoing what epidemiologists have said for years: The key to to understanding the next influenza pandemic is to study every available aspect of past ones. The situation now closely resembles that of the Spanish Flu and the Hong Kong Flu of 1968: A "herald wave" of a highly transmissible virus with low lethality. This enabled those viruses to spread quickly, infect a high number of hosts, and provide astronomical opportunities for antigenic shift, or reassortment of the recombinant DNA into another new novel strain.
What disease researchers hope will not happen is H1N1 infects a host (whether human, pig or bird) which has or may catch a pre-existing virus such as season human influenza A, (H3N2) or avian influenza subtypes (H5N1, H6N1 or H9N2). Update: Canadian farmer infects swine flock with H1N1. (Source: UK Times Online article - 5/4/09). This is why every health agencies around the world are working around the clock to glean as much data from this virus. Now the CDC has begun that drumbeat of concern for what may come this fall. (Source: Bloomberg article - 5/3/09)
Why would that be a problem? A long-studied theory is the idea of reassortment. Let's say today's virus reaches a host in Southeast Asia who has just been exposed to the bird flu, a virus with a 50% case fatality rate (421 confirmed cases, over 200 deaths). Inside that person's cells, both viruses exchange RNA and reassort into a completely new pathogen which retains the worse elements of both parents: Easily transmissible, highly lethal to certain populations. That is a snapshot of what may have happened in 1918: an entirely new strain that was so unusual, it even "tricked" the host's immune system into turning against itself. This describes the much-theorized "cytokine storm." (Source: Dr. Osterholm in Washington Post, 11/9/2005)
Since we're on the cusp of WHO declaring a full-blown pandemic, it's time you come face-to-face with what it means. No doubt the parents and school community of Milford Mill Academy in Baltimore County are quickly finding out what it means to "shelter-in-place" or implement "social distancing." The best part about a mild case of pandemic influenza is those individuals might have a better shot at overcoming the virus should it reassort prior to a second wave this fall. I am not making this up, it is based on volumes of research into what happened with the three previous major global epidemics. Nature and science have given us fair warning, because this changes everything.
Balancing caution with consistency