Comparative Assessment of Antibacterial Efficacy of four popular hand sanitizers sold in Nigeria

Despite the increase in popularity of hand sanitizers (HS) in Nigeria, there is a dearth of literature on the efficacies of these products. This study assessed the efficacies of four popular brands of HS in Nigeria against some clinically important bacterial pathogens. Using the well variant of the agar dilution method to determine antimicrobial susceptibility and the broth dilution method to determine minimum inhibitory concentration, the activities of the HS (HSF, HSM, HDT, and HSK) were evaluated against Staphyl ococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumonia . Each of the products displayed varying activities against the test organisms. HSM had the highest inhibitory effect against all the test organisms, while HSF was the least effective. S. aureus was the most susceptible organism, with the highest susceptibility to HSM (12.0 mm). P. aeruginosa was the most resistant organism, with the highest resistance to HSM (9.0 mm). Each of the HS was bacteriostatic against all of the test bacteria and none displayed bactericidal activity. HSM and HDT reduced the mean colonyforming unit (cfu) counts of bacteria on the hands of subjects by 72% and 62%, respectively. A onetailed t-test showed that HSM was more effective than HDT in this regard. None of the products could reduce bacterial counts by 99.9%, as the manufacturers claim. Such claims need to be verified to ensure that these products contain the correct quantities of active ingredients, and sellers need to store such products according to the manufacturers’ instructions.