Pulmonary candidiasis in a heroin addict: some remarks on its aetiology and pathogenesis.

Summary We describe a case of pulmonary candidiasis in a 26-year old drug-addict who had been recently submitted to a porto-caval by pass operation. This opportunistic infection appeared after an injection of heroin. The same patient was also found to suffer from a severe cellular immune response defect. No opportunistic fungal infections were observed, despite the frequent use of intravenous heroin, in a group of 20 parenteral drug addicts. The latter patients, however, were showing only minor abnormalities of their immunological status. Although in this case the main cause of the disease may have been the injection of heroin contaminated with the infecting organism, other important factors contributing to the development of opportunistic mycoses seem to be a reduced microbicidal capacity of the polymorphonuclear leukocytes and an impaired cell-mediated immunity.