Abstract
We investigated mold colonization of air handling units (AHUs) of heating, ventilating, and air conditioning (HVAC) systems and its effects, including invasive pulmonary mycoses and febrile neutropenia, in patients with hematological malignancies. Sample collection with transparent adhesive tape and culture swabs revealed that AHUs were heavily colonized with molds, including thermotolerant, variously distributed Penicillium spp. Cases of nosocomial invasive pulmonary mycosis were not clustered in specific patient rooms but did occur frequently when the HVAC systems were not in use, prior to intervention (i.e., sealing and disuse of AHUs in private room), and during construction of a new hospital building. Multivariate logistic regression analysis of initial episodes of febrile neutropenia showed that the rate of febrile neutropenia was significantly associated with the duration of neutropenia (odds ratio [OR]: 1.16; 95% confidence interval [CI]: 1.07–1.27) and with sex (OR: 0.469; CI: 0.239–0.902). An evaluation of private rooms showed that female patients also had a lower rate of fever after intervention (OR: 0.0016; 95% CI: 0.000–0.209). The reduced rate of febrile neutropenia after intervention suggests that mold colonization of AHUs had adverse effects on patients with hematological malignancies.
Acknowledgement
We thank Takashi Yanagawa for helpful advice in statistical analyses.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
This paper was first published online on Early Online on 2 September 2010.