Airborne microflora in the atmosphere of an hospital environment of University of Benin Teaching Hospital (UBTH), Benin City, Nigeria.

Abstract

A study was undertaken to determine typical concentrations of airborne bacteria and fungi (microflora) in Teaching Hospital environment in Benin City in the tropical rainforest environment of Nigeria. Aerial sampling was conducted at various hospital wards each day. The air samples were collected thrice daily. Concentrations of airborne microflora exceeded available local guidelines for indoor quality in the accident and emergency ward, female ward, male ward, pediatric ward and the maternity ward, but not in the restricted wards like the theatre, intensive care unit and bacteriological laboratory. The occupant density was the key factor influencing the levels of airborne microflora, while humidity was also observed as a factor, depending on the particular location with the hospital. The concentration of airborne bacteria and fungi in the nine different hospital units varied from wards to wards. The bacterial population ranges from 3.0 cfu/m to 76.0 cfu/m , with 33 the highest bacterial population recorded in the accident and emergency ward. The fungal population ranges from 6.0 cfu/m to 44.7 cfu/m , while the highest fungal population was recorded in the accident and 33 emergency ward. The microflora characterized and identified, were representative of the normal microflora of the human body (skin, gastrointestinal tracts, respiratory tract) and the opportunistic pathogens. The microbial isolates included six bacterial genera, among which are, Staphylococcus aureus, Staphylococcus epidermis, Escherichia coli, Bacillus sp. and Proteus mirabilis, the fugal isolates included, Aspergillus sp, Penicillium sp., Mucor sp., Candida sp and Verticillium sp. The concentrations of airborne microflora recorded in the hospital environment, specifically in the accident and emergency ward was significantly different from other wards