[Ip-health] Poverty, death, and a future influenza pandemic

[Ira Glazer]

This is the editorial comment by Niall Ferguson in the Lancet, on the
mortality estimates for a global flu pandemic.

['the stark fact that health inequity is scarcely less now than in 1918,
and the medical advances of the past 90 years are unlikely to benefit
much of the developing world in any future pandemic....so long as
pandemic vaccine manufacturing capacity is restricted to a small
fraction of the 350 million doses of seasonal influenza vaccine produced
annually, the extent of the developed world's commitment to a
global-health agenda for influenza pandemic preparedness will always be
questioned.]

The Lancet 2006; 368:2187-2188

DOI:10.1016/S0140-6736(06)69870-X


Poverty, death, and a future influenza pandemic
Neil Ferguson

History tells us that poor populations always endure a disproportionate
burden of disease and death from infectious diseases. This fact is as
true for pandemic influenza as for any other disease, as demonstrated by
contemporary studies after the influenza pandemic of 1918.
Internationally, the death toll from the 1918 pandemic was far higher in
poor countries, such as India and Iran, than in Europe and North
America. In today's Lancet, Chris Murray and colleagues present a
statistical analysis of the correlation between income and mortality in
the 1918 pandemic, and ask what might we expect now from a rerun of this
pandemic? They forecast that in today's world, a novel 1918-like virus
would cause a death toll of 62 million people worldwide, 96% of whom
would be in the developing world. In one respect, this conclusion is
academic since we will never see a precise rerun of the 1918 pandemic.
But it highlights the stark fact that health inequity is scarcely less
now than in 1918, and the medical advances of the past 90 years are
unlikely to benefit much of the developing world in any future pandemic.

Further work needs to be done to unravel the mechanisms by which poverty
affected mortality in the 1918 pandemic. Nutrition and
comorbidities=97such as a high prevalence of malaria=97have both been
implicated in the very high mortality seen in regions of Iran and other
areas. Malaria and malnutrition are still very much with us, but new
cofactors mean that Murray and colleagues=92 projections might be
optimistic. Of particular concern is the effect that a new lethal
influenza pandemic would have on the approximately 35 million people
currently infected with HIV, many of whom would be immunodeficient.
Furthermore, the log-linear relation assumed by Murray between mortality
and income per person means that future pandemic mortality in the
developed world is predicted to be at least threefold less than that
seen in 1918=97perhaps a rather optimistic conclusion.

The effect of antibiotics and modern medical treatment on pandemic
survival is unclear; for countries with stocks of antibiotics, mortality
in a rerun of 1918 might be substantially reduced. However, whether most
deaths in the 1918 pandemic were from viral or bacterial pneumonia is
still a point of contention. Certainly, mortality in human cases of H5N1
infection directly results from the viral infection. So long as
resistance does not become a major issue, prompt use of antiviral drugs,
such as neuraminidase inhibitors, should substantially reduce mortality.
However, large stocks of antibiotics or antivirals are unlikely to be
available in most resource-poor countries during a pandemic. Therefore,
perhaps the best estimate of mortality in a possible 2007 pandemic is
that from 1918=97a rather damning indictment of global equity in health car=
e.

So what can be done to mitigate the depressingly familiar wealth-related
distribution of disease burden predicted by Murray and colleagues?
Access to vaccines, antivirals, and antibiotics for the most vulnerable
populations is clearly part of the solution. New international health
regulations oblige countries to report suspicious clusters of novel
diseases. The socioeconomic effect of doing so has to be ameliorated by
the expectation that the reporting country will receive real help from
the international community. Even if the chances that a pandemic might
be contained at source remain slim in many areas of the world, detailed
planning for delivery of antiviral stockpiles to the first-affected
countries is in everyone's interest, both for the chance to at least
slow spread and for the implicit message of global solidarity. More
effort is needed though: so long as pandemic vaccine manufacturing
capacity is restricted to a small fraction of the 350 million doses of
seasonal influenza vaccine produced annually, the extent of the
developed world's commitment to a global-health agenda for influenza
pandemic preparedness will always be questioned.

Lastly, at the top of the pandemic preparedness agenda in the USA
currently is the enticing question of whether public-health
measures(such as school closure, household quarantine, or mask-wearing)
could substantially delay or reduce the effect of a pandemic. This idea
perhaps offers the most hope to countries without access to medical
interventions. The conclusions of an ongoing Institute of Medicine
inquiry looking at the evidence for non-medical interventions will be
eagerly awaited by many people in both the developed and developing world.
**