MICROBIOLOGICAL ASSESSMENT OF INDOOR AND OUTDOOR AIR
ABSTRACT
This study was aimed at investigating the microbial load and the quality of indoor air at Faith Mediplex Centre, Benin City, to ascertain their contribution to infection rate in the hospital. Air samples were assessed for three (3) months (June-August, 2015) using the settled plate methods. The study sites were divided into five (5) units; male medical ward, female medical ward, treatment room, operating theatre and outside the hospital gate. The result obtained reveal the isolation of six (6) bacterial isolates and four (4) fungal isolates which include Staphylococcus aureus, Staphylococcus epidermidis, Bacillus spp., Serrantia mercescen, Klebsiella spp., and Micrococcus spp. for the bacterial isolates, while the four (4) fungal isolates include Aspergillus niger, Aspergillus flavus, Penicillium spp.and Candida albicans. The highest bacterial load and fungal load of 95.5cfu/min and 43.5cfu/min respectively were recorded outside the hospital gate, and the lowest bacterial and fungal load of 45cfu/min and 26.5cfu/mins respectively were recorded in the male medical ward for both bacterial and fungal. The most frequently occurring bacterial and fungal isolates wereStaphylococcus aureus and Aspergillus nigerrespestively, occurring at 100%. All units that were included in the study were contaminated with bacteria and fungi. The bacteria and fungi concentrations of air obtained in this study might be potential risk factors for spread of nosocomial infection in the Hospital hence a high level of hygiene must be practiced by both patients and health care providers.
CHAPTER ONE
1.0 INTRODUCTION
Air supplies us with oxygen which is essential for our bodies to live. Pure air is a mixture of gases that are invisible, colorless and odorless consisting of 78% nitrogen, 21% oxygen and other gases as well as varying amounts of water vapor (Murray et al., 1995). This pure air can become contaminated in various ways affecting humans, plants and animals. Air pollution is the introduction into the atmosphere of chemicals, particulate matter or biological materials that causes discomfort, disease or death to humans, damage to other living organisms including food crops. Both indoor air and outdoor air can become polluted by pesticides. These pesticides contain active and inert substances such as cyclodiene which is associated with symptoms such as dizziness, headaches, weakness, muscle twitching and nausea (Hays et al., 1995).
Good indoor air quality (IAQ) is important for all of us; most people spend 90 % or more of their time indoors. Most of this time consists of the hours spent at home or at work, while school age children spend 20 % of their time in schools (Clench-Aas et al., 1999). Good IAQ consists of many aspects; it is an interaction of a functioning and efficient ventilation and the lowest achievable amount of chemical, inorganic or organic and microbial compounds which should not evoke symptoms in the occupants (Spengler et al., 2001).
Microorganisms such as bacterial and fungal spores are almost always present in the air. The quality of indoor environment, however, is not easily defined or readily controlled, and can potentially place human occupants at risk (Jaffal, et al., 1997a). Airborne transmission is one of the routes of spreading disease that is responsible for several nosocomial infections (Claudete et al., 2006).
Exposure to bio-aerosols, containing airborne microorganisms and their by-products, can result in respiratory disorders and other adverse health effects such as infections, hypersensitivity pneumonitis and toxic reactions (Gorny et al., 2002; Fracchia et al., 2006).
Indoor air quality is a term which refers to the air quality within and around buildings and structures especially as it relates to the health and comfort of its occupants. Indoor air can be polluted by various compounds such as carbon monoxide, volatile organic compounds (VOCs), particulate matter and microbial contaminants (moulds, bacteria, viruses) and any action that introduces harmful contaminants into the air within the building. The concern for quality indoor air is necessary especially in institutionalized settings that accommodate a large number of people such as hospitals, nursing homes, prisons, schools, family because contaminated air can cause both mild and severely irritating health conditions (Tambeker et al., 2007). The quality of air in hospitals in relation to microbial contamination at a given time period is determined by the quality of air entering into the building, the number of occupants in the building, their physical activities and resultant aerosol generation, human traffic and the efficiency of ventilation (Adebolu and Vhirterhre, 2002).
Indoor air quality in hospitals is a concern due to presence of airborne microorganisms that may cause nosocomial infections (Beggs CB, 2003). Few published reports have studied the seasonal fluctuations in microbial loads over time in hospital environment (Augustowska and Dutkiewicz, 2006). While studies in developing countries have documented presence of nosocomially significant bacteria and fungi in indoor air of healthcare facilities (Sudharsanam et al., 2008; Ekhaise et al., 2008), these studies were not performed over extended time periods to ascertain the influence of seasonal changes on airborne microbial loads.
Nosocomial infection also known as hospital acquired infection is an infection acquired in a hospital environment, which was not present in the patient at the time of admission (Beggs, 2003). Hospitals are potentially conducive for antimicrobial resistant and virulent pathogens to proliferate. Large numbers of microorganisms are found in indoor air and it is of great importance to carry out regular survey as a yardstick of determining standard of cleanliness in hospitals (Williams et al., 1956). The sources of hospital airborne infection or contamination could be traced to a variety of factors. These include the patient’s own normal flora, linens, bed sheets, staff clothes, visitors and the materials such as flowers. Activity of patients (sneezing, coughing, talking, yawning) and the number of patients per room may likewise be sources of hospital infection (Jaffal et al., 1997a; Ekhaise et al., 2008; 2010). It has also been reported that microbiological pollutants such as animal droplets, plants, building materials and air conditioning system have played significant role in the spread of airborne micro-flora. Materials such as files kept close to bedside in surgical wards have been implicated as a viable source (Burge et al., 2000).
1.1 AIMS AND OBJECTIVES
This study was aimed at investigating the microbial load and the quality of indoor air of four difference wards/units and outside the hospital gate of Faith Mediplex Centre, Benin City.
To isolate and characterize the airborne micro-flora from hospital environment and to ascertain their contribution to infection rate in the hospital.
