Abstract:
Background: Contaminated hands are the major mode of transmission of microorganisms from
one person to another. Hand washing or hand rubbing is normally practised to remove microbes
from the hands. If the hands are not visibly soiled, a handrub can be used as an effective
substitute for handwashing. With the pandemic of COVID-19, a large number of different hand
sanitizers were appeared at the market. The use of sub-standard hand sanitizers could give poor
assurance leading to disease transmissions.
Objectives: To determine the antibacterial efficacy of five different commercially available
Alcohol-Based Hand Sanitizers (ABHS) in Sri Lanka.
Methods: Samples of five different commercially available ABHSs, labelled as ‘A’, ‘B’, ‘C’,
‘D’ and ‘E’, and 70% in-house prepared alcohol solution were used for this study. Antibacterial
activity of each sample was determined using three methods. The phenol coefficient was
determined against Staphylococcus aureus (ATCC 25923) while the well diffusion method was
used to evaluate the antibacterial activity of the products against S. aureus (ATCC 25923) and
Escherichia coli (ATCC 25922). Activity indexes were calculated for each ABHSs in well
diffusion method. Each ABHS was used to determine the reduction of colony counts in hands
by hand hygiene with different hand sanitizers.
Results: Among the tested hand sanitizers, only the hand sanitizer ‘A’ exhibited a phenol
coefficient of 2.86. Others had phenol coefficient less than one. Activity indices of hand
sanitizers ‘A’ and ‘E’ were 2.75, 2.00 (against S. aureus) and 1.75, 1.44 (against E. coli),
respectively. ‘B’ and ‘C’ had 0.98, 0.81 against S. aureus and 0.79, 0.75 against E. coli,
respectively. Activity indices of ‘D’ had 0.00 against both organisms. All tested ABHSs and
70% in-house prepared alcohol solution significantly (p<0.05) reduced the colony counts in
hands as observed by the hand hygiene test.
Conclusions: Only the hand sanitizer ‘A’ was more efficient than the standard phenol solution.
Only the sanitizers ‘A’ and ‘E’ had better activity indices when compared with in-house
prepared 70% alcohol. Interestingly, all the tested ABHS were effective in significantly
reducing the colony counts in hands.
