Fungal Outbreaks and Infection Prevention During Demolition: Influence of High-Efficiency Particulate Air Filtration.

TO THE EDITOR—We read with interest the article by Kanamori et al [1] who reviewed fungal outbreaks linked to construction and renovation of healthcare settings. The authors selected 49 studies that reported cases of fungal outbreaks related to hospital construction, renovation, or demolition. The authors found that construction-related fungal cases seem to be in decline as only 3 published studies were conducted from 2010 to 2014 [2–4]. This may be explained by the introduction of guidelines regarding fungal infection prevention during construction [5, 6] and introduction of protective measures such as wet cleaning and air filtration. However, there is little evidence that specific control measures contribute to the prevention of fungal infections during construction and renovation. Indeed, guidelines and studies [7] recommend high-efficiency particulate air (HEPA) filtration for high-risk patients such as those with hematological malignancies. However, the metaanalysis by Eckmanns et al [8] revealed no significant improvement in the prevention of fungal infection among these patients with the use of HEPA filtration. In May 2015, we conducted a prospective study to determine the efficiency of HEPA filtration during demolition of a building that abutted 12 patient rooms of the department of clinical hematology. The rooms were equipped with HEPA filtration, and the beds were located under laminar airflow. The demolition work took place from 27 April 2015 to 12 May 2015. A laboratory technician took environmental samples from the patient rooms. Air samples were taken with the MAS-100 biocollector (Merck, Darmstadt, Germany) using Sabouraud chloramphenicol plates in the rooms (under the laminar airflow) and in the bathroom. Surface samples were taken using a biocontact applicator (Oxoid, Dardilly, France) in 5 locations in rooms and in 2 locations in the bathroom. Environmental samples were taken in the corridors of the hematology department to assess fungal contamination where there was no HEPA filtration. We collected 199 samples: 90 under laminar airflow from the rooms, 45 from bathrooms, and 64 from the corridors of the hematology department (Table 1). No air samples taken under laminar airflow were contaminated. Only 1 air sample taken from a bathroom retrieved Aspergillus versicolor and another unidentified filamentous fungus. At the same time, 16 environmental samples taken in the corridors retrieved fungus such as Aspergillus fumigatus and A. versicolor. Demolition work contaminated the hematology department but not the rooms equipped with HEPA filtration. Over the study period, no patient had fungal contamination or infection. Even if the metaanalysis by Eckmanns et al revealed no significant improvement in the prevention of death with HEPA filtration, our study highlights the efficiency of such filtration, notably under laminar airflow, in the prevention of fungal infection among patients with hematological malignancies during demolition work. We can reasonably presume that without this protection, some of the exposed patients would have been infected. We agree with Kanamori et al that further research is required to evaluate the risk of infection linked to fungal contamination during construction work and the real efficiency of protective measures such as HEPA filtration.