Don’t Worry, It’s Just Avian Affluenza
# 259
The article below is fairly typical of the flurry of reportage on the recently released Lancet Article: Estimation of potential global pandemic influenza mortality on the basis of vital registry data from the 1918–20 pandemic: a quantitative analysis
Experts Predict Avian Flu Pandemic Could Kill 62 Million People
By Jessica Berman Washington21 December 2006
A team of researchers predicts 62 million people could die if a long-feared avian-flu pandemic strikes, with the vast majority of the fatalities occurring in the developing world. VOA's Jessica Berman reports.
Kenneth Hill and colleagues of Harvard School of Public Health in Massachusetts came up with the mortality estimate by studying the death records of 27 countries from the 1918 Spanish flu pandemic, and applying the formula to the world's population of more than six billion people in 2004.
Hill says the model predicts that 96 percent of those who would lose their lives in a modern-day disaster live in the developing world.
http://tinyurl.com/y88dlh
Similar articles have appeared all over the media, although in some, the anticipated death toll is listed at 81 million, instead of 62 million. The actual number range given in the article is between 51 million and 81 million, with 62 million deaths being the median.
No matter. What really counts in all of this is the curious notion that were an avian flu pandemic to strike, the death toll would likely run about 62 million worldwide, and 96% of all deaths would occur in developing countries.
In other words, according to these numbers, only 2.48 million people would be expected to die from a pandemic in all of the United States, Canada, Europe, Japan, Australia, and the rest of the developed world. The remaining 59.52 million deaths would be absorbed by developing countries.
Obviously, something was missing in the mainstream reporting of this story, and so I went to the source, the Lancet Article, and poured over the charts, graphs, and accompanying text; squandering 2 hours of my life that I’ll never get back again.
The complete article can be found at:
http://tinyurl.com/tse7m
Admittedly, I’m not a scientist, nor did I go to Harvard, and so my qualifications to comment on this research are limited to a modicum of audacity on my part, my healthy sense of self-appreciation, and that fact that this is my blog.
Still, I’m going to go out on a limb, and call into question some of these findings.
The stated purpose of this study was to see if their theory: that the level of economic development of a country affected the mortality rates of the Spanish Influenza, could be proven statistically.
Setting aside the fact that you can prove almost anything statistically, I’ll grant that they have made a case that some lesser developed countries (India in particular) suffered fatality rates as much as 30 fold greater than more developed countries, like Denmark.
This, by the way, hardly falls under the category of `breaking news’. We’ve known all along that some countries fared far worse in 1918 than others. The idea that people who live in squalid, over crowded, and unsanitary conditions, bereft of medical services, and coincidentally lower on the socioeconomic scale, should fare worse during a pandemic is hardly groundbreaking.
Where I take exception to this report, and the conclusions of the esteemed authors, is when they attempt to take data from the 1918 pandemic and apply it to the next pandemic.
Using due diligence, and buried within the body of the report, the authors have listed a number of reasons why their forecasts might not be valid. The most telling of which follows:
In most discussions of influenza, the 1918–20 pandemic sets the upper limit, in terms of mortality, on what might occur in future pandemics. However, there is no logical or biological reason why that pandemic—albeit very severe— should represent the maximum possible mortality in a future pandemic.
Basically, this little disclaimer says that the death toll estimates in this report may, or may not; reflect that which we might see in the next pandemic.
Fair enough. The 62 million deaths is based on the Spanish Flu were it to occur in our modern world. Not, as widely reported, based on an Avian Flu pandemic. Different pathogen, ergo, producing different results.
But by looking closely at the charts and graphs, some interesting `adjustments’ to the 1918 mortality figures have been utilized in the updated figures.
In Table 3: Estimated number of deaths caused by the emergence of a pandemic influenza strain in 2004, the authors set the mean number of deaths in the United States at 383,881 (114,483–744,226).
This number is slightly more than half what we experienced in 1918, despite a 3 fold increase in population. The authors are apparently anticipating the death rate to be 1/5th of what we saw during the Spanish Influenza.
The authors explain this little anomaly away by stating . . .
. . .there are many cogent reasons to expect that the emergence today of a pandemic strain much the same as that which caused the 1918–20 pandemic strain would lead to much lower mortality than estimated here. First, symptomatic medical management is better now than in 1918–20.
However, although individuals with access to health care in high-income and middle-income countries might benefit, health-care systems could become overwhelmed, which would attenuate this effect. Second, antivirals such as zanamivir and oseltamivir phosphate might have a positive effect on the reduction of transmission and case-fatality rates.
Because we have not yet seen the next pandemic virus, the magnitude of this effect cannot be quantified. Third, vaccination with a lag of 4–6 months from the onset of a pandemic could reach a large fraction of the high-income populations.
. . . Fourth, in 1918–20, a large proportion of deaths was due to secondary bacterial pneumonia after primary viral pneumonitis. Antibiotics for pneumonia could have a substantial effect on case-fatality rates.
Affluent societies, according to these authors, due to better medical systems, anti-viral meds, antibiotics, and vaccinations, are likely to suffer far less during the next pandemic. Avian Affluenza, if this report is to be believed, is apparently not the problem we thought it would be.
I’ll grant, without reservation, that developing countries would be hit harder by the virus than economically developed countries. There does seem to be strong evidence that this was so in 1918, and I would expect to see that again in the next pandemic.
Where I take exception is the assumption that the mortality rates in the United States and other developed countries would be as little as 1/5th of what we saw in 1918, due to advances in medical care, antivirals, and vaccines.
According to the report card issued by the non-partisan Trust for America's Health, during a moderate pandemic, the majority of our hospitals would be overrun in 2 weeks. We currently have only a few million doses of a poorly matched vaccine, and the notion that we would have enough in a quantity to inoculate the nation in a matter of months is wildly optimistic. And as far as antivirals are concerned, if they are effective at all, we have enough for about 6% of the nation.
We may enter into the next pandemic with a medical advantage, but for most Americans, and residents of developed countries, the availability of advanced medical services will likely evaporate within weeks.
Two areas where we might carry some advantage are the availability of antibiotics for secondary bacterial pneumonias, and the relatively large percentage of our population that has received the pneumovax vaccination. Yet to date, even with the application of antibiotics and antivirals, the mortality rate of the H5N1 bird flu virus has exceeded 60%, so the effects of these medical interventions are as yet, uncertain.
The bottom line here is, that while this report provides us with some interesting insights into the 1918 pandemic, and a plausible explanation for why some countries fared better or worse than others, using this data to try to extrapolate the outcome of the next pandemic would seem to me to be more speculation than science.
The underlying message in this report is that developed nations are less at risk than developing nations, and therefore our resources should be directed at interventions in poorer nations, which will suffer disproportionately during the next pandemic.
This is a humane, and altruistic view that I share, but also temper with the knowledge that we do ourselves, and the world, no favor if we ignore our own vulnerabilities in favor of those of the developing world. Should a pandemic emerge, a crippled developed world would be unable to help in the recovery of developing nations, and in the end, that could cost even more lives.
I know how that sounds. But it in no way makes it any less true. We need to ensure that our own house is in order, while doing what we can reasonably do for other countries.
Assuming that our relative wealth and prosperity conveys some sort of immunity against a pathogen like the H5N1 virus is a leap of faith that I, for one, am not willing to take.
But, on the plus side, this report has sparked dozens of news articles with headlines screaming `62 million deaths from the next pandemic’.
And if that catches a few people’s attention, I’ll consider it worthwhile.
