Clinical aspects of anaerobic infection

Abstract

Summary This paper is a review of clinical aspects of anaerobic infections considered in the light of current anaerobic cultural techniques. Three themes recur from clinical observations, first, that certain conditions predispose to anaerobic suppuration—compromised blood supply, tissue destruction or antecedent infection with aerobic bacteria or viruses. These conditions produce low oxidation-reduction potential (Eh) favourable for growth of anaerobes. Second, that anaerobes are secondary invaders in which the inaugural event is spread of normal flora beyond the confines of mucocutaneous barriers. The third observation is that at the infected site there is, in many anaerobic infections, a complex bacteriological flora. The classical idea of, ‘one organism, one disease’ is no longer tenable in these situations. Clinical clues to the possible presence of anaerobes as a cause of infection include, site of infection (on or close to mucosal surfaces), presence of foul-smelling discharge, severe tissue necrosis, gas in tissues, failure to culture aerobes where sepsis is obvious, and failure of chemotherapy when drugs inactive against anaerobes are used. Anaerobic infections in the head and neck, chest, abdominal cavity, female pelvis and soft tissues are described in detail, relating clinical features, site of- infection and bacterial pathogens—emphasising the role of anaerobes.