A leak in compliance with ventilation system maintenance instructions resulted in an aspergillosis outbreak

Gulcin Dizman, Gokhan Metan, Dolunay Gülmez, Zeynep Bastug, Ömer Dizdar, Sevtap Arikan-Akdagli, Serhat Unal

Author address: 

Hacettepe Üniversitesi Tıp Fakültesi, Ankara, Turkey


Background: Invasive aspergillosis (IA) is an important cause of morbidity and mortality in patients with hematologic malignancies. Here, we shared our experience for an aspergillosis outbreak in an oncology hospital in November 2017.

Materials/methods: Detection of four consecutive patients with IA who were hospitalized in the same ward triggered an outbreak investigation. A case was defined as any patient with clinical symptoms that could be related to IA after at least 1 week of hospitalization and Aspergillus spp isolation from culture. Possible causes of the outbreak were questioned. Samples for fungal culture were taken from the ventilation system outlets in the patient rooms.

Results: Although there were no cases that matched with the case definition in October, four cases were detected in November. All patients with IA had neutrophil count <500 mm3 , Aspergillus fumigatus or Aspergillus flavus were isolated from respiratory samples of three patients and sinus biopsy culture of one patient. Three patients were diagnosed as probable pulmonary IA and one patient was diagnosed as Aspergillus sinusitis according to EORTC/MSG definitions for invasive mold diseases.

The investigation revealed that the filters of the ventilation system were changed in all patient rooms without compliance with the institutional instructions for maintenance and repair for air conditioning and ventilation system. Patients were kept in their rooms without any air protection during the filter change and all further steps such as; use of hepafiltered cleaner, cleaning and disinfection of the room and change of curtains and sheets were missed. Aspergillus spp (Aspergillus fumigatus, Aspergillus niger, Aspergillus spp),Paecilomyces spp Chrysonilia spp and unspecified mold growth were detected in environment cultures. N95 masks were recommended for all the neutropenic patients in the ward and they were quickly transferred to other wards. New patient admissions were stopped. After then, the air conditioning filters were changed according to the instructions, ventilation system and the rooms were cleaned and disinfected. After the intervention, no fungal infection (pneumonia or sinusitis) was detected in the first quarter of 2018 (Figure 1).

Conclusions: Any leak for infection control precautions can lead to severe consequences. Continuous education and surveillance are crucial. 

Presenter email address: [email protected]


abstract No: 


Full conference title: 

European Congress of Clinical Microbiology and Infectious Diseases 2020
    • ECCMID 30th (2020)