Invasiv aspergillose : En oversikt over muggsoppfunn i autopsier ved Oslo Universitetssykehus, Rikshospitalet

Abstract

OBJECTIVE This study was conducted as a part of an ongoing fungal study project at the Microbiological Department at Oslo University Hospital, Rikshospitalet. The aim was to answer two questions: 1 What is the current knowledge of invasive aspergillosis (IA)? 2 How can we interpret the findings of mold in autopsy material?

BACKGROUND Invasive fungal infections are an increasing challenge. More than 80 % of the invasive mycoses are caused by either Aspergillus or Candida spp. Patients suspectible to IA usually suffer from bone marrow failure or are otherwise severely immunocompromised due to their underlying disease or treatment, e.g. patients with hematologic malignancies, congenital or acquired immunodeficiency, transplant recipients, patients with malignant tumors and those with severe autoimmune disorders. There are approximately 20 different species of Aspergillus pathogenic to humans, fumigatus being the most important. Early diagnosis is crucial for successful treatment. Diagnostic gold standard is direct detection by cultivation, staining and microscopy, but often clinicians must rely on indirect methods such as radiology or detection of fungal enzymes, metabolites and DNA. Treatment of IA consists of a combination of antifungal therapy and reversal of the immunosuppression. There are several effective drugs among polyens, azoles and echinocandins. For certain patient groups the prophylactic anti mold treatment is recommended.

METHOD In the first part of this paper the basic issues of invasive mold infections with emphasis on and illustrated by aspergillosis are discussed. The overview is based on a variety of research, reviews and textbook articles found by specific search through PubMed in the current databases Medline and the Cochrane Library, and by following relevant references listed in relevant scinetific articles. In the second part, data from autopsies and clinical records at OUS-RH over a period of three years 2008-2011 is presented and discussed.

RESULTS There were 36 unique cases where the cultivation and/ or autopsy detected mold. The lists from the Pathological and Microbiological departments were not identical. 26 out of 36 (72%) of cases appeared to be contamination, leaving 10 out of 36 (28%) to be concidered real infections. The incidence was steady – 2 to 4 per year. 7 out of 10 infections were located to lungs. The age of the patient population ranged from 24 to 67, with median of 58.5 years. 7 out of 10 were treated for hematologic malignancies. In 6 out of 10 cases the invasive mold infection was not suspected ante mortem. 7 out of 10 patients were treated with antifungals effective against mold. 3 out of 10 patients where the autopsy diagnosed inasive mold infection were neither suspected to have one or treated for such.

DISCUSSION The figures calculated here are not statistically significant due to limited sample size. The patient population is special and the diagnosis itself rare. An extensive under-reporting is suspected. The sample of ten cases in this study was congruent with the general knowledge about such infections. In all the cases there was an underlying impairment of the immune system, the majority had hematologic malignancy, most of them had pulmonary involvement. Most infections were due to Aspergillus, predominantly fumigatus.