ABSTRACT
The use of alcohol-based hand sanitizer that contains at least 60% alcohol prevents the spread of infections and thus prevents the spread of antimicrobial resistance. Due to continuing worldwide COVID-19 pandemic, the demand for hand sanitizers remains at a very high level. The aim of this study was to evaluate the antimicrobial efficacy of different brands of hand sanitizers sold in Nigeria. Antimicrobial efficacy of eleven popular brands of alcohol-based hand sanitizers sold in Nigeria was evaluated and comparatively analyzed using a combination of Agar well diffusion (Mueller-Hinton Agar for bacteria and Sabouraud Dextrose Agar for fungi), Broth dilution (Nutrient broth) and In vivo Viable Microbial count reduction techniques. A total of 330 clinical isolates comprising 55 each of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris and Candida albicans obtained from culture collection were used as test organisms. The organisms were chosen because they are commonly implicated in community transmission of infectious diseases. The test organisms were standardized using McFarland standards. This study revealed a very high significant difference (P<0.001) on the Susceptibility pattern of the test organisms against the various hand sanitizers used. The study showed a very high significant difference between the activity of the various hand sanitizers and the positive control (P<0.001). All hand Sanitizers used in this study apart from Purit are less active against Proteus vulgaris but are more active against Staphylococcus epidermidis. The findings in this study showed that isopropyl alcohol based-gel form Hand sanitizer has 82.2% efficacy while ethanol-based gel form hand sanitizers has 76.9% efficacy. This study revealed Significant difference (P<0.001) on Minimum Inhibitory Concentration (MIC) of all Hand Sanitizers used against test organisms except for Evree Hand Sanitizer which showed no significant difference (P>0.05) on Minimum Inhibitory concentration against test organisms. Of all the hand sanitizers used in this study only Purit has bactericidal activity against Proteus vulgaris not lower than 95% concentration. Lifebuoy, Dettol, Sanitol, Seed, Tribute and Evree have bactericidal effects not lower than 100% concentration on other test organisms. Carex, Temosol, 2Sure and Wind hand Sanitizers have no bactericidal effect on test organisms and that Purit, Lifebuoy, Tetmosol and Evree have fungicidal effects on Candida albicans at concentration not lower than 100%. Dettol, Carex, Sanitol, 2Sure, Wind, Seed and Tribute hand Sanitizers sold in Nigeria, used in this study did not have fungicidal effect on test organism. The mean percentage in vivo reduction of viable bacteria and fungi counts observed in this study is lower than 99.9% claim by manufacturers of hand sanitizers. This study revealed that Purit hand Sanitizer is more active against bacteria than fungi in in-vivo reduction of viable microbial count on the hands of Volunteers not lower than 82% bacteria counts, Evree has equal in-vivo reduction of viable bacteria and fungi on the hands of subjects not lower than 76% while lifebuoy has in-vivo reduction of bacteria on hands of subjects not lower than 41% but more potent in in-vivo reduction of fungi on the hands of subjects not lower than 64%. The results of this study suggest high significant difference in the antimicrobial efficacy of various hand sanitizers sold in Nigeria.
