This is a response to the letter to the editor by J Silver entitled: ‘Re: Case report: a fatal metastasis of Klebsiella pneumonia of the lungs’, Spinal Cord (2009) 47, 901–902; doi:10.1038/sc.2009.96.

Dr Silver has expanded the discussion of pulmonary involvement in septic conditions by pointing out reports of septic pulmonary emboli in the preantibiotic era.1, 2 At the same time Austin Flint wrote: ‘The [infectious] embolus brings with it some poison which acts as an intense inflammatory irritant… It is [also] probable that the poison may be carried by the blood in a finely molecular form.’3 Dr Silver's work supports these mechanisms of pulmonary infection by pointing out the frequency of clinically unsuspected bacteremia in spinal cord injury patients with a septic source.4 Such a progression of infectious disease has been described in the fatality reported here, shown by the sequential culture of the same organism from the urinary tract and bronchial tissue.5

Because of the central location of the lungs, their filtration of the entire circulation and the predominance of pulmonary failure as a cause of death in the SCI population,6 it can be suspected that bacterial seeding of the lungs is greatly underestimated. The various pulmonary pathologies encountered—bronchitis, atelectasis, pleural effusions, pneumonia, and pulmonary infarctions—may often have an infectious basis carried from a remote source. Aspiration pneumonia is a common label applied to pulmonary pathology. However, blood cultures as suggested by Dr Silver and a search for a primary source as suggested by the case reported might very well expand our understanding of the mechanism of pulmonary disease in this population.