Publication:

Is fumigation enough for air conditioning units in operation theatres and Intensive care units?

Background Strict asepsis is necessary in operating theatres (OT) and intensive care units (ICU) as the patients undergo invasive procedures. The filters of contaminated air conditioning (AC) units provide a niche for proliferation of fungi and production of fungal spores.

Methods The routine procedure for maintenance of sterile atmosphere in our hospital, i.e. fumigation and mopping walls with disinfectants often fail to address these fungal spores of the AC filters. We therefore carried out a surveillance of the ACs in ICUs and OTs to find the level of contamination with fungal spores and also to improvise on intervention strategies to tackle the problem. Over 3 months period, 34 ACs from 7 OTs and 2 ICUs were screened by taking 2 swabs from each AC which were then tested for the presence of fungal spores as per standard methods.

Results The contamination rate was 88.2% before fumigation and 76.9% after fumigation. The fungal spore contamination rate was reduced to 20% (1 out of 5 ACs) after servicing of the ACs was done. Aspergillus spp. was the most common fungal isolate.

Conclusion Based on the observations, we recommend regular servicing of the ACs as well as wet mopping of the ducts with sporicidal solution at regular intervals.