A New Look at an Old Disease

This fall marks the 90^th anniversary of the 1918-1919 Influenza Pandemic. For those of us with an interest in the history of medicine, two recent articles from the professional literature are of interest. But first, a bit of history will serve to demonstrate the significance of these reports.

Although the mortality rate will never be accurately known, it has been hypothesized that between the fall of1918 and the summer of 1920 the influenza pandemic caused anywhere between 50 to 100 million deaths worldwide and between 700 thousand to 1.5 million deaths in the United States alone.

A hallmark of this pandemic was that it was reported to have killed a disproportionate number of otherwise healthy young adults. The majority of these victims succumbed to a rapidly-progressing variant of what is now called Acute Respiratory Distress Syndrome (ARDS) which may have resulted from the virus causing an over-reactive response from the body's immune system, a condition known as "cytokine storm."

Although the public image of the 1918-1920 pandemic is usually one of large numbers of people rapidly succumbing to the virus, recent research indicates that a majority of deaths during that period came several weeks after the viral illness had subsided and were due to bacterial pneumonia rather that the direct effects of the virus itself.

In "Deaths from bacterial pneumonia during 1918-19 influenza pandemic" Brundage and Shanks examined historical records from both the United States and Australia and found that less than 5% of deaths occurred within 3 days of the onset of symptoms and that the "median time from illness onset to death was 7-10 days, and significant numbers of deaths occurred >2 weeks." Had a "hyper-virulent" virus itself been the primary cause of death, they observe, the greatest number of deaths should have occurred early in the course of illness rather later. Using published descriptions of the disease dating from the height of the pandemic as well as hospital records they demonstrate that the initial viral illness predisposed the victims to a later infection from bacteria normally found in the respiratory tract (such as pneumococcus, Group A strep, and staphylococcus).

These findings are confirmed by Morens et al in "Predominant Role of Bacterial Pneumonia as a Cause of Death in Pandemic Influenza: Implications for Pandemic Influenza Preparedness." By conducting an independent historical review of the medical literature from the period, as well as reexamining lung specimens taken from victims at autopsy and preserved in paraffin, the authors confirm that only about 4% of the deaths did not show evidence of bacterial pneumonia

In light of these findings, the authors then consider the overall direction of national pandemic contingency planning in the United States.

As the authors note, recent contingency planning has emphasized both routine and crisis immunization programs as measures to both prevent, and if all else fails, to contain a pandemic involving a new strain of influenza virus such as the 2004 H5N1 "Bird Flu." In the light of their findings the authors suggest that such costly, and resource-consuming, investigations targeted at identifying potentially pandemic viruses in order to develop vaccines might be better spent on national stockpiles of antibiotics and expanded research on immunizations against more common disease organisms.

Comment

In an editorial accompanying the report by Morens, Jonathan McCullers of the Department of Infectious Diseases at St. Jude's Children's Hospital in Memphis notes that "this information

Dr. McCullers is correct in his assessment, but he fails to mention the role of political pressures on funding agencies (tead "the United States Government") in response to "scare headlines" generated by the media.

During the fall of 2004 it was almost impossible to avoid hearing the near-incessant charges that the Bush Administration "was turning a deaf ear" to the "demands of the public" that it do more to "prepare" for the guaranteed-to-occur "global pandemic" that would occur once the "Bird Flu" escaped China. The same charges were leveled against the Clinton Administration 6 years earlier, when it was charged that he was "too preoccupied" with his upcoming impeachment to appreciate the "danger" posed by yet another virus that was deadly only if you happened to be, literally, a chicken.

One need only recall the near-disastrous response of the Ford Administration to the non-existent "Swine Flu Crisis" of the 1970s as an example of what can happen when political expediency replaces scientific reasoning. For those who do not recall the details of this bureaucratic fiasco, or are simply too young to be aware of those events, this link will be of particular benefit.

It isn't often that I get the opportunity, or have a reason, to praise scientific research as having a potential immediate application. The reports discussed above represent the results of science in its truest sense. It remains to be seen whether good science will be able to influence the actions of a self-serving bureaucracy.