"Superspreaders" May Trigger Infectious Outbreaks in Hospitals

Healthcare workers (HCWs) who roam from patient to patient in a hospital ward may play a disproportionate role in spreading pathogens. Laura Temime and colleagues at France's National Institute of Health and Medical Research (INSERM) used a mathematical model of a hypothetical intensive care unit to determine how easily common hospital-based infections, including antibiotic-resistant Enterococci or Staphylococcus aureus, spread. The work appears in the current issue of Proceedings of the National Academy of Sciences (PNAS).

The researchers separated HCWs into three groups: a "nurse-like" group, which made frequent visits to a small number of assigned patients; a "physician-like" group, which made infrequent visits to a larger number of patients; and a "peripatetic" group, which, like a physical therapist or radiologist, visited all patients daily.

The authors found that infection outbreaks increased when HCWs failed to follow standard handwashing procedures. However, the infection rates increased by up to three times more when a peripatetic HCW failed to wash his or her hands compared with a HCW from the other groups.

The infection rate from a single peripatetic HCW failing to wash their hands was equivalent to the infection rate when 23 percent of all HCWs on the ward failed to hand wash. The researchers suggest that the unusual profile of peripatetic HCWs makes them potential "superspreaders," indicating that hygiene measures in hospitals may need to be done individually rather than globally.