Microbial load of indoor airborne bacteria and fungi in a teaching hospital in Ghana

The hospital, even though a place for the sick people, is inhabited by medical staff, administrative, security and patients who may share common microbes in the hospital environment. Some of these organisms may be pathogenic and may pose health hazard to humans through inhalation in the hospital atmosphere. Hence, the objective of this study was to investigate the microbial load of airborne microorganisms in some selected units of the Tamale Teaching Hospital and to suggest possible means to reduce the load. The microbial loads of nine units of the Tamale Teaching Hospital were estimated. Passive air sampling technique, applying open Petri-dishes containing different culture media, was employed to collect sample twice daily for the two seasons witnessed in Ghana. The concentrations of airborne microorganisms in the indoor environment of the wards ranged between 277.61 – 5395.14 CFU/m3. The statistical analysis showed that the highest bacterial and fungal loads, 5395.14 CFU/m3 and 2021.87 CFU/m3, respectively were recorded in outpatient department (OPD) and the least, 492.37 CFU/m3 and 277.61 CFU/m3, respectively observed in the theatre ward. Staphylococcus aureus, Escherichia coli and Bacillus subtilis were among the bacterial isolates. The fungal isolates include: Aspergillus spp., Alternaria spp., and Fusarium spp. Generally, all units of the hospital harbored very high concentrations of bioaerosols, except the theatre ward.