A prospective study on factors influencing aspergillus spore load in the air during renovation works in a neonatal intensive care unit

The relationship between air contamination (cfu/m(3)) with fungal spores, e specially Aspergillus spp., in three renovation areas of a neonatal intensi ve care unit (NICU) and colonization and infection rates in a high care are a (HC) equipped with high efficiency particulate air (HEPA) filtration and a high pressure system, was evaluated. Data on the type and site of renovat ion works, outdoor meteorological conditions, patient crowding and nasophar yngeal colonization rate were collected. Factors not associated with Asperg illus spp. concentration were outdoor temperature, air pressure, wind speed , humidity, rainfall, patient density in the NICU, renovation works in the administrative area and in the isolation rooms. Multivariate analysis revea led that rt novation works and air concentration of Aspergillus spp. spores in the medium care area (MC) resulted in a significant increase of the con centration in the HC of the NICU. The use of a mobile HEPA air filtration s ystem (MedicCleanAir(R)Forte, Willebroek, Belgium) caused a significant dec rease in the Aspergillus spp. concentration. There was no relationship betw een Aspergillus spp. air concentration and nasopharyngeal colonization in t he neonates. Invasive aspergillosis did not occur during the renovation. Th is study highlights the importance of optimal physical barriers and air fil tration to decrease airborne fungal spores in high-risk units during renova tion works. The value of patient surveillance and environmental air samplin g is questionable since no relationship was found between air contamination and colonization in patients. (C) 2000 The Hospital Infection Society.