Maîtrise du risque fongique environnemental dans les établissements de santé

Abstract

In the attempt of chemoprophylaxis that has been proved to be effective, prevention of hospital-acquired fungal infection is currently based on air-control measures with monitoring of environmental fungal contamination. It is the most important way to significantly reduce the incidence of nosocomial aspergillosis in particular. High-risk patients should thus benefit from air treatment such as high-efficiency particulate air (HEPA) filtration, laminar airflow systems, and high rates of room-air changes, positive pressure, and well-sealed rooms. Prevention strategies should also fight contamination from the many other sources of spore transmission, food, water etc. Monitoring of environmental fungal contamination detects increases in conidia density and assesses the efficiency of air filtration. Monitoring of air and surface fungal loads is highly recommended (i) in hospital units, which benefit from air control measures, and (ii) during specific investigations in the case of Aspergillus infection. We describe the current French regulatory procedures on hospital environmental surveillance. The French Afnor recommendation (NF S 90 351) specifies different tests to evaluate the effectiveness of protective measures during installation of the system and once it is up and running. These tests include specific biocontamination controls. The French hospital guidelines specify that each hospital is responsible for the air and the water they provide to the patient, and that air-control efficiency must be monitored. Optimal environmental monitoring requires efficient and specific methodologies to detect fungal spores in addition to bacteria.