Nurses more prone to infections during night shifts: study

By Stephen Beech

Nurses are more vulnerable to common infections such as colds due to working night shifts, warns new research.

Scientists examining the effects of sleep patterns and shift work on the immune system found that sleep "debt" and night shifts increase the risk of several infections in nurses.

While essential in sectors such as healthcare, growing evidence suggests that shift patterns can have a negative impact on workers' well-being.

The new study, which analyzed self-reported data from 1,335 Norwegian nurses, found that shift work – particularly night shifts – was associated with a higher risk of several infections, including the common cold.

The findings, published in the journal Chronobiology International, emphasize the importance of adequate sleep and shift management in reducing susceptibility to infection.

Study senior author Dr. Siri Waage, coordinator at the Norwegian Competence Center for Sleep Disorders, said: “These findings highlight the need for tailored interventions to reduce infection risks among healthcare workers.

“Sleep debt and irregular shift patterns, including night work, not only compromise nurses’ immune health but could also impact their ability to provide high-quality patient care.”

The participants, mostly female nurses with an average age of 41.9, reported their sleep duration, sleep needs, shift work patterns, and how often they had experienced specific infections over the previous three months.

Statistical analyses, adjusted for factors such as age, gender, marital status, and childcare responsibilities, revealed a "clear link" between sleep debt, night work and infection risk.

The study found that sleep debt, defined as the gap between sleep need and actual sleep duration, increased infection risk in a "dose-dependent" manner:

Nurses with moderate sleep debt - less than two hours of sleep needed - had a 33% higher risk of the common cold, while those with severe sleep debt - over two hours - had more than double compared to those with no sleep debt.

The risk of pneumonia or bronchitis was 129% higher for moderate sleep debt, and 288% for severe sleep debt.

Both sinusitis and gastrointestinal infections also showed higher risks with increasing levels of sleep debt.

The analysis further revealed that night work was linked with an increased risk of the common cold, but was not associated with any of the other infections examined.

In contrast, sleep duration and "quick returns" - short intervals between consecutive shifts - were not associated with infection risk.

The research team says their findings suggest that ensuring sufficient sleep may help prevent infections, although further studies are needed to determine cause-and-effect relationships.

The team put forward several methods that might help reduce sleep debt and potentially lower infection risks among nurses in the future.

Study co-author Dr. Ståle Pallesen, of the University of Bergen, Norway, said: “Nurses could benefit from optimized shift patterns, such as limiting consecutive night shifts and allowing adequate recovery time between shifts."

He added: “Raising awareness about the importance of sleep for immune health and encouraging regular health screening and vaccinations for healthcare workers may also be helpful.”