En-suite bathrooms in protected haematology wards: a source of filamentous fungal contamination?

Abstract

In spite of 25 recently built high-risk haematology rooms with a protected environment and fitted with en-suite bathrooms in our university hospital centre in 2008, sporadic cases of hospital-acquired invasive aspergillosis remained in these wards. This study aimed to identify unsuspected environmental sources of filamentous fungal contamination in these rooms. Over two months, environmental fungal flora in the air (150 samples) as well as air particle counting and physical environmental parameters (airspeed, temperature, humidity, pressure) were prospectively monitored twice on the sampling day in all 25 protected rooms and en-suite bathrooms in use, and on bathroom surfaces (150 samples). In rooms under laminar airflow, in the presence of patients during sampling sessions, fungi were isolated in two samples (4%, 2/50) with a maximum value of 2cfu/500L (none was Aspergillus sp.). However, 88% of the air samples (44/50) in the bathroom were contaminated with a median range and maximum value of 2 and 16cfu/500L. Aspergillus spp. were involved in 24% of contaminated samples (12/44) and A.fumigatus in 6% (3/44). Bathroom surfaces were contaminated by filamentous fungi in 5% of samples (8/150). This study highlighted that en-suite bathrooms in protected wards are likely to be a source of fungi. Before considering specific treatment of air in bathrooms, technicians have first corrected the identified deficiencies: replacement of high-efficiency particulate air filters, improvement of air control automation, and restoration of initial technical specifications. Assessment of measure effectiveness is planned.