Sunday, August 03, 2008

EID Journal: Bacterial Pneumonia and Pandemic Planning


# 2201



This month's Journal of Emerging Infectious Diseases, from the CDC, has a good article on the need to plan for treating secondary bacterial pneumonia during a pandemic.


Here is the abstract, and then some discussion.  







Volume 14, Number 8–August 2008


Bacterial Pneumonia and Pandemic Influenza Planning


Ravindra K. Gupta,*  Robert George,† and Jonathan S. Nguyen-Van-Tam‡
*John Radcliffe Hospital, Oxford, UK; †Health Protection Agency, London, UK; and ‡University of Nottingham, Nottingham, UK




Abstract  (Reparagraphed for Readability)

Pandemic influenza planning is well under way across the globe. Antiviral drugs and vaccines have dominated the therapeutic agenda.


Far less work has been conducted on stockpiling and planning for deployment of antimicrobial drugs against secondary bacterial pneumonia, a cause of substantial illness and death in previous pandemics and epidemics.


In the event of a pandemic, effective antimicrobial drug measures are expected to substantially benefit public health. We address issues regarding use of antimicrobial drugs as stocks of individual agents are diminished and the role of resistance surveillance in informing such policy.


Furthermore, vaccination with polysaccharide and conjugate pneumococcal vaccines is considered as part of a pandemic strategy.


Most illness and death from influenza are likely to occur in developing countries, where neuraminidase inhibitors and vaccines may be neither affordable nor available; thus, compared with industrialized countries, the benefits of treating bacterial complications in developing countries may be substantially greater.


(Continue Reading . . . )



There is a good deal here to read, and is worth your time to follow the link.


This article is basically a companion piece to a historical review I blogged about on July 18th -   If you missed the comments section on that piece, there is a lengthy commentary left by a doctor that is well worth reading.



Brundage JF, Shanks GD. Deaths from bacterial pneumonia during 1918–19 influenza pandemic. Emerg Infect Dis. 2008 Aug; [Epub ahead of print]



The authors of today's article go on to recommend government stockpiling of specific antibiotics, and a vaccination strategy using the various pneumonia vaccines available.



        *            *          *          *         *          *






The last great pandemic (1918) occurred years before the virus theory had been accepted by the scientific community.   Bacteria, we knew about - but the existence of viruses had barely been recognized.  


It would take another 15 years before the influenza virus would be identified.  



While there are theories about a virus induced cytokine storm being responsible for many of the deaths during the Spanish Flu,  gradually that idea has been falling out of favor - or at least has been modified.   



Today, many scientists believe that a good deal of the excess mortality experienced in the 1918 pandemic was due, not so much to the viral infection itself, but to secondary bacterial pneumonia.   



Granted, with no knowledge of viruses, just about all of the contemporaneous accounts of complications due to the Spanish Flu were attributed to `influenzal pneumonia' or `purulent bronchitis'.  Both were believed to be of bacterial origin.



Here is how the Lancet described an outbreak of purulent bronchitis in Europe, the year before the Spanish Flu broke out.  It is very similar to other accounts from the 1918 pandemic:



Clinically, the prominent signs were the characteristic yellow purulent or mucopurulent sputum, tachycardia, and cyanosis.


The pathological findings were thick purulent material in the smaller bronchi from which frequently air was excluded; in some cases secondary broncho-pneumonia, edema, and emphysema. The lungs were almost always bulky.



And this does indeed sound like an aggressive bacterial infection.


Many of us carry, in our lungs or nasopharynx, colonies of bacteria that - under normal circumstances - remain dormant.   When we get a viral infection, we set up ideal conditions in our lungs for these bacteria to grow.  



When that happens, a secondary bacterial pneumonia can set up.



While the Cytokine Storm theory hasn't been completely abandoned, we do know that millions of people each year develop secondary bacterial pneumonia as a direct result of developing a viral infection.    Many of the `flu fatalities' each year are really the result of a secondary bacterial pneumonia.



This is an observable, and well documented, correlation.



The need for antibiotic stockpiles during a pandemic, therefore, is readily apparent.   Antivirals, alone, won't do the trick.  



The call for a vaccination strategy with with polysaccharide and conjugate pneumococcal vaccines  (23-valent and 9-valent pneumonia vaccines) also makes a good deal of sense.   Prevention is always preferable to trying to cure.



All of this proves that there are no easy solutions, no  one-pill-fixes-all treatment during a pandemic.   And while we can draw much value from looking at past pandemics, the old epidemiologist's lament holds true:



"If you've seen one pandemic . . . you've seen one pandemic"



Past performance is no guarantee of future results.  


We could very well find ourselves dealing with unforeseen problems during the next pandemic. 


Hopefully, those that go through the `pandemic-after-next'  will have a lot more hard science behind their preparedness efforts than we have behind ours.