Comparison of Total Bacteria Concentration on Computer Keyboards with Different Clean Methods

Abstract

Public computer keyboards can be contaminated with total bacteria because this equipment is handled by multiple-user computers who are in various hygienic behavior. Consequently, contaminating hands of the users can contact to the computer keyboards. Using inappropriate clean method for the computer keyboards, this cause the opportunity for the transmission of contaminating microorganisms. The study of total bacteria concentration on the computer keyboards with different clean methods was quasi-experimental study in order to compare total bacteria concentration on the computer keyboards between cleaning the computer keyboards with a feather duster and alcohol. Samples were aseptically collected from each computer keyboard by swab test for 31 samples with duplicated sampling. Total bacteria concentration was investigated by using spread plate method. In addition, the questionnaires and the record forms were used to collect data of computer using from 60 student-users. The results of analysis with independent sample t-test at 95 % confidence interval showed that total bacteria on the computer keyboard with maximum using-frequency was significantly higher than the computer keyboard with minimum using-frequency which were 17.23 and 12.43 CFU/50 cm2, respectively (p-value = 0.0005). Furthermore, total bacteria on computer keyboard cleaning with a feather duster present in 14.75 CFU/50 cm2 which was significantly higher than cleaning with alcohol present in 1.21 CFU/50 cm2 (p-value<0.001). Moreover, the total bacteria concentration after cleaning by alcohol was reduced by 93.74% compared to before cleaning. Whereas the total bacteria concentration after cleaning by a feather duster was decreased by 23.69% compared to before cleaning.
The results indicate that using different clean methods including the number of users and different hygienic behavior of public computer using can affect the total bacteria concentration and might be pathogenic reservoir which may cause adverse health effect of contacted users. Therefore, computer keyboard with high using-frequency should be cleaned with chemical substance such as 70% alcohol. This method could decrease bacteria better than cleaning with a feather duster method. Moreover, raising awareness on cleaning of such surfaces and adequate hand hygiene should be addressed for cleaning workers and users.