Hand washing with soap and water together with behavioural recommendations prevents infections in common work environment: an open cluster-randomized trial

Abstract

Background: Hand hygiene is considered as an important means of infection control. We explored whether guided hand hygiene together with transmission-limiting behaviour reduces infection episodes and lost days of work in a common work environment in an open cluster-randomized 3-arm intervention trial.

Methods: A total of 21 clusters (683 persons) were randomized to implement hand hygiene with soap and water (257 persons), with alcohol-based hand rub (202 persons), or to serve as a control (224 persons). Participants in both intervention arms also received standardized instructions on how to limit the transmission of infections. The intervention period (16 months) included the emergence of the 2009 influenza pandemic and the subsequent national hand hygiene campaign influencing also the control arm.

Results: In the total follow-up period there was a 6.7% reduction of infection episodes in the soap-and water arm (p = 0.04). Before the onset of the anti-pandemic campaign, a statistically significant (p = 0.002) difference in the mean occurrence of infection episodes was observed between the control (6.0 per year) and the soap-and-water arm (5.0 per year) but not between the control and the alcohol-rub arm (5.6 per year). Neither intervention had a decreasing effect on absence from work.

Conclusions: We conclude that intensified hand hygiene using water and soap together with behavioural recommendations can reduce the occurrence of self-reported acute illnesses in common work environment. Surprisingly, the occurrence of reported sick leaves also increased in the soap-and water-arm.

Trial registration: ClinicalTrials.gov: NCT00981877

Source of funding: The Finnish Work Environment Fund and the National Institute for Health and Welfare.

Figure 1

Trial design, recruitment and reporting.

Figure 2

Reporting coverage in the study arms.

Figure 3

a) Temporal distribution of all infection episodes/weekly reports in different intervention arms during the study. C, control arm; IR1, soap and water using arm; IR2, alcohol-based hand rub using arm. b) Respiratory viruses detected in the study between January 2009-May 2010. Influenza detections during November-December 2009 consist of pandemic influenza A/H1N1. Other viruses includes adenovirus (N = 1), respiratory syncytial virus (N = 1) and parainfluenzaviruses (N = 7), c) Respiratory virus findings reported to the National Infectious Disease Registry in Finland. Other virus includes adenovirus (N = 872), respiratory syncytial virus (N = 4048) and parainfluenzaviruses (N = 608).

Figure 4

Results of the survey of behavioral habits. C, control arm; IR1, soap and water using arm; IR2, alcohol-based hand rub using arm. Results of January 2009 (yellow) represent baseline before any of the recruited office work employees had received guidance on hand hygiene.