The Microbial Load of Indoor Airborne Bacteria and Fungi in a Teaching Hospital in Ghana

  • Enoch Kwaku Larrey COMSATS University Islamabad
  • Jacob Laryea University for Development Studies – Ghana
  • Stephen Kpordze University for Development Studies
  • Courage Saba University for Development Studies
Keywords: Indoor air, Microbial load, Sedimentation technique, Open-plate technique, Hospital environment, Bacteria, Fungi.


Background and Objective: The hospital as a healthcare institution with highly trained medicinal and nursing staff rendering patient treatment can also be a potential source and reservoir for pathogenic microorganisms. Hence, the objective of this study to investigate the microbial load of airborne microorganisms in some selected units of the Tamale Teaching Hospital and to suggest possible means to keep the load at the barest minimum. 

Methods: The microbial load of nine units of the Tamale Teaching Hospital was 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 (dry and wet).

Results: The concentrations of bacteria and fungi aerosols in the indoor environment of the wards ranged between 277.61 – 5395.14 CFU/m3. The statistical analysis showed that the concentrations of both bacteria and fungi that were measured in all studied units were significantly different from each other (p-value < 0.001). Moreover, the concentrations of bacteria that were measured at different sampling time (morning and afternoon) were significantly different (p-value =0.001). Also, seasonal variation had a significant impact on the concentration of bacteria and fungi in the various units. The p-values for bacteria and fungi were < 0.001 and 0.001 respectively for seasonal influence on microbial concentration. Time on the other hand did not have a significant effect on the microbial concentration.

Conclusion: Generally, all units that were included in the study were heavily contaminated with bacteria and fungi except theatre ward. Thus, immediate interventions are needed to control those environmental factors which favor the growth and multiplication of microbes. It is vital to control visitors’ access to the wards. Moreover, it is imperative that efficient measures be adopted to keep the microbial load in the hospital environment on the low.


Adams, R. I., Bhangar, S., Pasut, W., Arens, E. A., Taylor, J. W., Lindow, S. E., Bruns, T. D. (2015). Chamber Bioaerosol Study: Outdoor Air and Human Occupants as Sources of Indoor Airborne Microbes. PLOS ONE, 10(5), e0128022.

Adebolu, T. T., & Vhriterhire, K. J. (2002). Survey of the microbial flora of the Ondo State Specialist Hospital Environment, Akure, Nigeria. Niger J Microbiol, 16(112), 91–94.

Bhatia, L., & Vishwakarma, S. R. (2010). Hospital indoor airborne microflora in private and government-owned hospitals in Sagar City, India. World J Med S, 5(3), 65–70.

Ekhaise, F O, Ighosewe, O. U., & Ajakpovi, O. D. (2008). Hospital Indoor Airborne Microflora in Private and Government Owned Hospitals in Benin City , Nigeria. Journal of Medical Sciences, 3(1), 19–23.

Ekhaise, F O, Isitor, E. E., & Idehen, O. (2010). Airborne microflora in the atmosphere of an hospital environment of University of Benin Teaching Hospital (UBTH), Benin City, Nigeria. World J Agric Sci, 6(2), 166–170.

Ekhaise, Fred O., & Ogboghodo, B. I. (2011). Microbiological Indoor and Outdoor Air Quality of Two Major Hospitals in Benin City , Nigeria. Sierra Leone Journal of Biomedical Research, 3(3), 169–174.

Fanger, P. O. (2000). Indoor air quality in the 21st century: search for excellence. Indoor Air, 10(2), 68–73.

Fekadu, S., & Getachewu, B. (2015). Microbiological assessment of indoor air of teaching hospital wards: A case of Jimma University Specialized Hospital. Ethiopian Journal of Health Sciences, 25(2), 117.

Fracchia, L., Pietronave, S., Rinaldi, M., & Martinotti, M. G. (2006). The assessment of airborne bacterial contamination in three composting plants revealed site-related biological hazard and seasonal variations. Journal of Applied Microbiology, 100(5), 973–984.

Hänninen, O. O. (2011). WHO guidelines for indoor air quality: dampness and mold. In Fundamentals of mold growth in indoor environments and strategies for healthy living (pp. 277–302).

Hyvärinen, A., Vahteristo, M., Meklin, T., Jantunen, M., Nevalainen, A., & Moschandreas, D. (2001). Temporal and Spatial Variation of Fungal Concentrations in Indoor Air. Aerosol Science and Technology, 35(2), 688–695.

Jaffal, A. A., Banat, I. M., El Mogheth, A. A., Nsanze, H., Bener, A., & Ameen, A. S. (1997). Residential indoor airborne microbial populations in the United Arab Emirates. Environment International, 23(4), 529–533.

Leech, J. A., Nelson, W. C., Burnett, R. T., Aaron, S., & Raizenne, M. E. (2002). It’s about time: A comparison of Canadian and American time–activity patterns. Journal of Exposure Science & Environmental Epidemiology, 12(6), 427–432.

Nazaroff, W. W. (2016). Indoor bioaerosol dynamics. Indoor Air, 26(1), 61–78.

Obbard, J. P., & Fang, L. S. (2003). Airborne concentrations of bacteria in a hospital environment in Singapore. Water, Air, and Soil Pollution, 144(1–4), 333–341.

Owusu, K., & Waylen, P. R. (2013). The changing rainy season climatology of mid-Ghana. Theoretical and Applied Climatology, 112(3–4), 419–430.

Pasquarella, C., Pitzurra, O., & Savino, A. (2000). The index of microbial air contamination. Journal of Hospital Infection, 46(4), 241–256.

Rainer, J., Peintner, U., & Pöder, R. (2001). Biodiversity and concentration of airborne fungi in a hospital environment. Mycopathologia, 149(2), 87–97.

Rintala, H., Pitkaranta, M., Toivola, M., Paulin, L., & Nevalainen, A. (2008). Diversity and seasonal dynamics of bacterial community in indoor environment. BMC Microbiology, 8(1), 56.

Weiss, K. D., Osborne, S. F., & Callahan-Lyon, P. (2010). Prevention of surgical-site infections. The New England Journal of Medicine, 362(16), 1541–1542; author reply 1543-4.