SUPER INFECTION

Super infection may be defined as the emergence of bacteriological and clinical evidence of a new infection during the chemotherapy of primary one.

This phenomenon is very common and potentially dangerous b/c eradication of microorganisms responsible for super infection is very difficult with available anti microbial. Among the various adverse effects of antibiotics, alteration in the normal microbial population of skin, respiratory tract, GIT and gastro-urinary tract is of special importance b/c it leads to the development of the super infection. The normal flora play a vital role in the maintenance of health and causation of disease by the following ways:

The normal flora can cause disease especially in immuno-compromised and deliberated (weak) individuals. Although these microorganisms are non-pathogens in their usual anatomic location, they can be pathogen of other parts of body.

They constitute protective host defense mechanisms. The non-pathogenic bacteria occupy ecologic niches (place of organism with in its community) and so pathogens have difficulty in multiplying efficiently. If the normal flora is suppressed, pathogens may grow and cause disease.

They may serve the neutral function. The intestinal flora may produce several vitamins B and vitamin K. Poorly nourished may suffer vitamin deficiency when being treated with antibiotic due to reduction in normal flora.

Many member of normal flora appear to produce antibacterial substances (Bacteriocins). They also compete with pathogens for essential nutrients.

Thus broader the effect of antibiotic against microorganisms, greater the attraction of normal flora and hence greater the possibility that a single microorganism may become predominantly invade the host and produce infection.

The incidence of super infection is least with penicillin G and higher with chloramphenicol, tetracycline and highest with combination of broad-spectrum antibiotics and expanded with 3^rd generation Cephalosporins.

The prolonged use of anti microbial also increases the incidence of super infection. In fact the after effects (harmful) of prophylactic or therapeutic use of anti microbial must never defer the physician from its administration in a situation where they are definitely needed. Utmost care should be taken in employing anti microbial for their right use. Other wise irrational use may convert a simple benign disease into a serious or even a fatal one.