Microbial Causes Of Apparently Non Infectious Diseases

*Associate Professor,Unit of Clinical Microbiology,**Principal lecturer,Unit of Pathology,School of Medicine,AIMST University,Semeling,08100,Kedah darul aman,(Malaysia).

Dear Editor,

Microbial causes of diseases previously believed to be noninfectious in origin, are increasingly being recognized (1). Even though the association of Streptococcus pyogenes with rheumatic heart disease is well known, it was the discovery of Helicobacter pylori as a cause of peptic ulcer disease that revolutionized the significance of the hypothesis that microbial agents may contribute to the pathogenesis of apparently non infectious diseases. Establishment of the aetiology of human infections has traditionally relied on cultivation of microorganisms and a demonstration of infection in animal models, i.e., Koch's postulates. However, the advent of molecular biology techniques has made the association of these agents simpler. Another example includes the identification of Chlamydia pneumoniae in atherosclerotic plaques, thereby associating the agent with
myocardial infarction(2). Few other examples are tabulated in (Table/Fig 1).

Apart from the few examples cited above, there are a host of articles associating microbes with diseases ranging from psychiatric conditions to cancers. A few already established microbial causes of chronic diseases with their possible mechanism of causation have been tabulated in (Table/Fig 2)

Most importantly, the significance of the hypothesis that certain infectious agents contribute to chronic disease process, is related to the possibility that interventions such as vaccines or antimicrobial therapy may be effective in the primary or secondary prevention of these conditions. For instance, azithromycin is a prophylactic for atherosclerosis (11).