Investigating microbial transfer on desktop keyboard
Bacterial species wereisolated from computers located in different places in the University. This isolated 21 different bacterial species which were later disinfected to test on the efficacy of the disinfectants against the microbes commonly found on computer key boards. Of the 21 colonies identified, only a few were included in the write up as the rest were too few to count. The results show that key boards with multiple users such as those found in the microbiology laboratory, the learning resource centre, and those in the Perry library had high colony counts, and a total of twelve bacterial species were isolated from the samples. Potentially pathogenic bacteria such as Bacillus subtilis and Staphylococcus aureus were identified in the samples. In order to identify the colonies, different media were used, which tested positive for both the gram positive and negative bacteria, as shown in table 1. The total number of Colony Forming Unit / ml of the isolated microorganisms were calculated using the equation (30- 300 CFU/ml) X dilution X volume pipette on plate (0.1 ml X 10). The results show that the results of the isolates ranged between 1.2 X 104 – 7.8 x 103cfu/ml, as shown in Table 2.
Table 1: Identification of Isolates
|Isolate number||Media used||Media||Gram stain|
|1||Nutrient agar||Staphylococcus aureus||Gram positive|
|2||Nutrient agar||Bacillus subtilis||Gram positive|
|3||Malt agar||Yeast and mould|
This confirmed the presence of the bacteria in the samples obtained from the keyboards from different locations. Most of the computers sampled tested positive for pathogenic bacteria with limited occurrence of mould and yeast, as shown in table 1. It is important to note that S. aureus is a normal part of the microbiota found in the nasal passages and on the human skin, although it is also known to be linked to a number of diseases (Anderson and Palombo, 2009). B. subtilis are mostly found in the soil and vegetation (Dijl and Hecker, 2013) and indicate the presence of environmental contamination on these computers. Mould and yeast on the computers also indicate the presence of airborne fungi in the environment (Anderson and Palombo, 2009).
Table 2: Microbial load on keyboards in a variety of locations
|Location of keyboard||Number of keyboards swabbed||CFU/ml|
|Library X 101||1 2 3||2.5 x 103 6.2 x 103 6.8 x 104|
|Learning Resource X 103||1||7.6 x 105|
|Microbiology Laboratory X 101||3||1.2 x 104 3.2 x 103 8.2 x 103|
|Lecture room E7 X 102 Room FW10 X 101||1 1||6.0 x 104 7.8 x 103|
As shown in table 2, the number of potentially pathogenic bacteria was great on keyboards with multiple users, with the highest count at 8.2 x 103 found in computers in the microbiology laboratory and the lowest count at 1.2 x 104, also found in the microbiology lab, which was still higher than bacterial swabs of individual computers. The particular bacteria and contaminants present in each location are as shown it table 3.
Table 3: each of this location
|location||Number of swabs||1 Bacillus.s||Media isolated 2 Staph.aureus||3 Mould /yeast|
|B learning r||3||positive||negative||negative|
All the computers tested positive for B.subtilis and S. aureus apart from computers in the learning resource that tested negative for S.aureus. Only computer samples from the library tested positive for yeast and moulds. In order to determine the effectiveness of the common disinfectants against these commonly occurring microbes, they were used to disinfect the keyboards. The keyboards were sampled after disinfection and the bacterial count was taken to determine the effectiveness of the disinfection. Dettol and Disifin, the commercial brands of disinfectants that widely available and widely used, were used. Dettol wipes were used to disinfect computers in the microbiology lab, the lecture room and a personal computer while Disifin was only used for computers in the microbiology library, as shown in table 4.
Table 4: Dettol and Disifin Universal Cleaner
|Dettol universal wipes||Disifin universal cleaner|
|Micro biology lab||Microbiology|
|Castle lecture room|
After disinfection, the computers were swabbed and bacterial counts done. Table 5 shows that the disinfectants are effective in reducing the bacterial counts on the keyboards, but not in totally eliminating bacteria. In all the computers sampled, the level of B.subtilis and S. aureus was significantly reduced.
Table 5: Disinfectant effect on microbial growth
|Location||Before disinfecting 1 2||After disinfecting 1 2|
|Microbiology Laboratory||Both 1 and 2 staphy and bacilus||Reduced to staph. Aureus|
|Castle Lecture||Staph present||reduced|
In recent years, computers are found in almost all aspects of human life, including places of residence, work place, and even recreational facilities. In the Universities, computers are necessary tools that students, professors, and the administrators use for different learning, teaching, and research activities. It was previously thought that microbes are present only in the hospitals and clinics, or in an unhygienic environment such as the toilet or bathroom. However, recent studies carried out to determine the bacterial content of both personal and multi user computers disprove this theory, as it was found out that these gadgets are contaminated by various pathogenic microbes. It is important to note that most people are unaware of the germs present in computer parts, which necessitates awareness campaigns to make the public aware of the changing dynamics, as lack of knowledge on the occurrence of germs could lead to adverse health complications among some people (Ali et. al., 2013; Tagoe and Ansah, 2010).
Work done by previous authors has shown that inanimate objects such as money, door handles, phones and computers act as breeding grounds for the colonization by bacteria and play an important role in their transmission (Oluduro et. al., 2011). It is reported that 100% of University students have access to computers, with 92% using computers on a regular basis (Ali et. al., 2013). Multi user computers have been put in place on campus to accommodate this large use of computers, which means that they are handled by a number of users on a daily basis. Routine disinfection of computers as a practice has not set in and the computers hold great potential for transmitting potentially harmful pathogens (Enemuor, et. al., 2013).
The results of this study agree with previous work which shows that computer surfaces in a university setting may be contaminated by microbes due to a multi user environment where access to the computers is not restricted, and there is possibility for contamination by individuals who are carriers of the specific bacteria (Enemuor et. al., 2013). The major bacterial colonies isolated from the study (B.subtilis and S. aureus) are also consistent with bacterial isolates from other studies (Ali et. al., 2013, Anderson and Palombo, 2009, Alemu et. Al., 2015, Enemuor, et. al., 2013, Oluduro et. al., 2013). Bacillus bacteria are known to ubiquitous which gives it a greater ability to colonize the environment, and its spores have developed resistance to environmental changes and can withstand chemical disinfectants and dry heat (Ali et. al., 2013). As mentioned, S. aureus is commonly found on human skin and nostrils which makes it occur frequently as a contaminant. It is easily introduced into the environment through contact with the skin or through coughing and sneezing. It is also recognized as a causative agent in human diseases especially in pus forming infections (Enemuor, et. al., 2013).
The bacterial count in multi user computers has been found to be higher than in single user computers (Anderson and Palombo, 2009). For instance, the computers in the library, lecture rooms and microbial lab are accessed by a large number of people who may or may not comply with the standards of hygiene, and who may also be carriers of the identified bacteria. Areas in which multi user computers are located are also areas of high traffic, for instance in the library and lecture halls, where people are constantly moving up and down. In such an environment, it is possible that some people could be sick and eventually deposit some pathogens onto the computer keyboards, either by air or physical transmission (Ali et. al., 2013). In contrast, single user computers are limited to one person, which is a much lower risk of contamination. In such an environment, the risk of contamination from individual carriers of pathogenic bacteria is higher than in the individual computers. In a single user computer, it is also possible to maintain hygienic and sterilization techniques which may not be possible in a multi user computer, leading to a higher bacterial count.
Although this study did not carry out an investigation on the sterilization procedures employed by the staff, the isolation of bacteria from the keyboards shows that whatever procedures are employed are not effective. Sterilization using Dettol and Disifin was shown to be effective in reducing the microbial load, but the nature of multi user computers where access is not limited may make disinfection of computer surfaces only slightly effective in reducing the microbial load and transfer, unless applied on a regular basis (Anderson and Palombo, 2009).
Computer keyboards are an ideal reservoir and breeding ground for pathogens due to the presence of crevices and corners which make it difficult to reach during cleaning. The keyboards also become warm during use, and provide a suitable environment for bacteria to multiply in. In a multi- user computer environment, this greatly increases the chances of cross infection from one user to another. Some strategies should be put in place to reduce the bacterial load in multi- user computers. Microbe- inhibiting flexible keyboard covers could be useful in reducing microbial keyboard contamination. The covers are made of a polyutherane material that is molded to accurately fit the keyboard and protect the keyboard from dust, dirt, liquids and contaminants without inhibiting the use of the keyboard. It gives the keyboard a smooth surface with no corners in which the microbes can lodge in and multiply, thus reducing the microbial load. The keyboard cover is easier to keep clean and measures should be put in place to incorporate their use in a multi- user keyboard environment.
In order for materials such as flexible keyboard covers to be effective, simple hand hygiene procedures such as cleaning the hands with hand wash before and after using computers should be adopted to reduce the chances of cross infection (Ali et. al., 2013, Saleh, 2015). These practices should be encouraged and other practices such as eating and drinking near computers should be discouraged to reduce the risk of food particles spilling on the computer. A regular schedule for cleaning and disinfecting the keyboards should also be put in place. Keyboards should be covered where possible and cleaned and disinfected at least weekly to reduce the microbial load on the surfaces (Enemuor, et. al., 2013).
The presence of bacterial populations on surfaces such as computer keyboards in the university is an indication of the lack of awareness among the university population of the need to practice hand hygiene and to disinfect such surfaces (Alemu et. al., 2015). The university is responsible for adhering to public health standards and providing a safe environment for students and staff, and for reducing the chances of diseases spreading throughout the university community. Awareness programs should be put in place to pass information on the risks posed by computer keyboards and the measures that can be put in place. Efforts aimed at inculcating a culture of responsible health practices should be put in place (Kassem et. al., 2007). They should be made aware of bacteria containing fomites such as the skin and nostrils which can transmit Staphylococcus. This is important to reduce the incidences of hand- nose or hand- mouth contact when using keyboards (Kassem et. al., 2007). Awareness should also be made on the appropriate hygienic and decontamination procedures. In areas where multi- user computers are in use (lecture hall, library, microbiology laboratory), hand washes and hand sanitizers should be placed strategically and their use should be encouraged before and after handling computer keyboards. This will be effective in limiting the spread of the infection spreading microbes through- out the community. Regular cleaning and disinfection of computers should also be initiated and implemented throughout the university. It is important that these measures are put in place to promote the welfare of the population, since a disease outbreak will directly affect the students through poor performance, and the staff through low productivity in the university.
Limitations of the study
One of the major limitations of the study is that there was limited work done on personal computers, much of the research was focused on multi user computers. Although this has given useful results concerning multi user computer in the university setup, a comparison with bacterial counts would have been more useful in making inferences and recommendations. Future work should consider incorporating single user computers in such studies. The study swabbed three computers from each location and made inferences based on them, which is a small number when compared to the numbers used in previous studies. Eltablawy and Elhifnawi (2009) collected samples from 24 computers while other studies have collected data from an even higher number. This is a limitation of the study as it could have an effect on the numbers and range of the various microorganisms identified.
The key board surface is not flat and presented some difficulties on swabbing. The keyboard was swabbed by moving moistened swabs over the surface to be tested. This technique is similar to work done by other authors (Eltablawy and Elhifnawi, 2009; Malik and Naeem, 2014). The computers were swabbed on different keys, for instance those in the library were swabbed on the top keys from the escape key to the page break key while computers in the learning resource centre were swabbed from the ctrl key on the left to the ctrl key on the right. Though literature is scarce documenting this, there may be a possibility that the uneven swabbing may distort the data. This is therefore one limitation of the study. This study is also limited because computer mice were not included in the sampling process. Computer mice, like keyboards are also reservoirs of pathogenic bacteria as they are also in contact with a large number of people, and people routinely eat and drink near them (Awe et. al., 2013, Engelhert et. al., 2008, Haamzeh and Nawas, 2015, Hartmann et. al., 2004). In order to widen the scope of the study, computer mice should have been swabbed when the key boards were being swabbed.
Investigations were not made concerning the protocol followed by the university on cleaning the computer. This could have been useful to organize collecting the samples during the time when it is expected that the bacterial counts are at the highest and lowest levels and make inferences based on this. In some cases, the keyboards were aged while others were fairly new. In the older keyboard, the surface was not as smooth as in the newer keyboards. It may be possible that the bacteria thriving in the older keyboards maybe of a different species and population (may be higher in number), and this was not captured in the study. It would have been useful if when swabbing, the samples would have been marked to identify the samples from the old computers and those from the new ones and make conclusions based on this. As it is, the study may be limited due to the physical characteristics of the computers which are not accounted for in this study.
Conclusion and Recommendations
Computers and computer surfaces may act as agents of transmitting pathogenic bacteria. Measures such as washing the hands or using hand sanitizers before and after using computers have been suggested as strategies of reducing the bacterial count to an acceptable level (Ali et. al., 2013, Saleh, 2015). Although these measures may be effective, it may be difficult to enforce them and ensure compliance among the university population (Anderson and Palombo, 2009). The bacterial levels obtained from the computer surfaces shows that more can be done to reduce their levels to an acceptable range. The use of common disinfectants such as Dettol and Disifin has been shown to be effective in cleaning keyboards and other surfaces and reducing the bacterial load. Disinfectants should be used regularly to clean computer surfaces and mice to reduce bacterial loads to an acceptable level (Ali et. al., 2013, Enemuor, et. al., 2013; Messina et. al., 2013). It is also important that practices such as eating near the computer key board is avoided. Food particles may drop and become dislodged in the key board, making it difficult to clean and provide breeding ground for pathogens.