Background

Acute infectious diseases are major causes of short periods of days off from work, day care and school. These diseases are mainly caused by viruses and hands have a key role in their transmission. Thus, hypothetically, they can be controlled with means of intensified hand hygiene. In this study we aim to elucidate the effect of acute infectious diseases on the work contribution in common office work and study the influence of improved hand hygiene on possible reduction of infectious disease episodes and days off from work due to acute infectious diseases.

Design

The voluntary participants have been recruited from six companies in the Helsinki region. The designated 21 study clusters were identified as operationally distinct working units each containing at least 50 people. The clusters were matched and randomized based on results of a pre-trial contagion risk survey. Improved hand hygiene is being executed with guided hand-washing with soap and water in one intervention arm and with alcohol based hand rubbing disinfectant in the other. Participants in both arms have received guidance on how to avoid infections and how to implement contagion stopping habits. A control arm is acting as before regarding hand hygiene. Data collection for evaluation of the efficacy of the interventions is based on self-reporting through weekly electronic reports. The questionnaire is enquiring about possible respiratory or gastrointestinal symptoms during the preceding week, and requests a daily report of presence of symptoms and working capacity. Etiology of the symptoms is not searched for individually, but contribution of different viruses is evaluated by sentinel surveillance, where occupational health clinics located in the premises of the participating companies collect specimens from employees visiting the clinic. Common causative agents of the diseases are being searched for using real-time PCR techniques. The duration of the intervention will be 16 months. Primary endpoints of the study are the number of reported infection episodes in a cluster within a time frame of 100 reporting weeks and the number of reported sick leave episodes in a cluster within a time frame of 100 reporting weeks.

Trial Registration

ClinicalTrials.gov Identifier: NCT00821509