Hand hygiene is considered an effective intervention in the fight against the transmission of viruses and bacteria that cause respiratory infections. But which is better at preventing their ambulatory spread –disinfectantsor hand washing with soap and water? An Australian research team recently addressed this question in asystematic review with meta-analysis and dose-response analysis. For this purpose, a total of 18 randomised controlled trials were included: four of them directly compared disinfectants and soap with each other, 14 assessed disinfectants or soap in comparison to a control group. In addition, a closer look was taken at those studies that also considered the "dose" (i.e. the frequency of the intervention) to determine the relative risk of respiratory infection.
Head-to-head comparisons too heterogeneous to clearly favour disinfectant or soap
The four head-to-head studies that directly compared hand sanitisers with soap and water differed greatly in design. While a two-arm Swedish study in day-care centres found a 12% lower rate of absenteeism among those using disinfectants, children in a two-arm Spanish study had a 13% lower risk of respiratory infection in the disinfectant group. Both studies thus found an advantage of hand sanitizers compared to soap and water. In contrast, in a three-arm Kenyan study in primary schools, both disinfectants and water plus soap resulted in a 23% lower risk of infection in school children than the control without intervention. Therefore, the two interventions were to be considered equivalent here. The situation was different in a three-arm Finnish study in companies, where significantly fewer episodes of infection occurred in the soap group than in the control group (5 vs. 6 per year), but the difference between disinfectant group and control (5.6 vs. 6 per year) was not significant. Apart from this, however, the study could not find any difference between the two interventions in terms of absenteeism from work.
Differences in efficacy not explained by frequency of intervention
In the meta-analysis, three studies using soap and water compared to the control yielded a non-significant result, while six studies using disinfectants found a significant 20% reduction of respiratory infections (pooled data) compared to the control. Eleven of the total studies included provided sufficient information to estimate the frequency of hand hygiene events. However, they did not show a clear relationship between frequency and efficacy, so differences in efficacy between hand sanitizer and soap and water cannot be explained by this.
Properly used, both methods contribute to fewer respiratory illnesses
Overall, the research team concluded thathand hygienehas a moderate but important role in reducing respiratory disease transmission. Provided the interventions are carried out appropriately, both hand disinfection and hand washing with soap can reduce the risk of transmission. However, some evidence from the studies suggested that disinfectants may be more effective in practice.
While the use of hand disinfectant has its place in healthcare anyway according to the "5 Moments of Hand Hygiene", soap and water are usually sufficient in private settings or non-health-related facilities. However, if available,hand disinfectantsshould be used if communicable diseases are known in the environment. This also applies to possible contact with pathogens, when dealing with immunocompromised people and when there is no possibility to wash hands.
Join in and clean your hands thoroughly on a regular basis. Here, you will find information on how to wash and disinfect your hands properly. In doing so, you will help to prevent infections and protect your health and that of those around you!