Sleep debt, defined as the gap between sleep need and actual sleep duration, increased infection risk in a dose-dependent manner. The risk of pneumonia/bronchitis was 129 per cent higher for nurses with moderate sleep debt and 288 per cent for severe sleep debt. Night work was linked with an increased risk of the common cold, but was not associated with any of the other infections examined. The study emphasises the importance of adequate sleep and shift management in reducing susceptibility to infection, according to researchers from the Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen. The findings highlight the need for tailored interventions to reduce infection risks among healthcare workers, said Siri Waage, from the Norway Competence Centre for Sleep disorders, in a press statement on Monday. The research, published in the journal Chronobiology International, examined the effects of sleep patterns and shift work on the immune system among 1,335 nurses from Norway. It was carried out by researchers at Haukelands University Hospital in Bergen and the Norwegian Sleep Disorders Center in Oslo.