INVESTIGATION OF BACTERIAL-INFECTIONS OF THE LOWER RESPIRATORY-TRACT

Conventional microbial methods can yield an aetiological diagnosis in almost all of the patients admitted with community-acquired pneumonia. Sputum examination, if accurately performed, is still one of the most important diagnostic tools, Antigen detection, especially for pneumoc occal antigen, is a valuable and rapid method for diagnosing pneumococ cal pneumonia even during antibiotic treatment, Because of the high fa tality rate in severe community-acquired pneumonia, invasive procedure s may be indicated and are useful; they are preferably performed befor e antibiotic treatment is initiated. Bronchoalveolar lavage has the ad vantage of sampling secretions from a relatively large part of the lob e, and this fulfils the requirements for appropriate specimens for all microbiological procedures. Polymerase chain reaction is the most pro mising new diagnostic technique in pulmonary infections, It can detect DNA or RNA of a low number of microorganisms with high accuracy in di fferent biological fluids, Larger studies are necessary to investigate the impact of this technique on the aetiology, treatment and outcome of community-acquired pneumonia. Although serology is useful for aetio logical and epidemiological studies, in the majority of cases the resu lts of serology are available only after completion of treatment, and therefore seldom influence the choice of specific antibiotic.