Study: Healthcare providers may be at greater risk for exposure to flu

Some people infected with the flu may shed more of the airborne virus than others and current infection control recommendations may not be sufficient, according to a recent study.

Researchers at Wake Forest Baptist Medical Center screened 94 patients at the medical facility for flu-like symptoms during the 2010-2011 flu season. The authors of the study then took nasal swabs and obtained air samples from within one foot, three feet and six feet of patients during routine care, Medical News Today reports.

Of the 94 patients studied, 61 tested positive for the flu virus and 26 others released influenza into the air. Five of the patients shed up to 32 times more virus than others.

"One out of five influenza-emitting individuals released elevated amounts of virus into the environment, pointing to a highly infectious subgroup," Werner Bischoff, the lead author of the study, said, according to Medical News Today. "Additionally, the patients who emitted more virus also reported greater severity of illness."

Current infection control recommendations for providers of healthcare focus on preventing transmission by large particles, using fitting respirators only during aerosol-generating procedures.

"Our study provides new evidence that infectiousness may vary between influenza patients and questions the current medical understanding of how influenza spreads," Bischoff said, according to Medical News Today. "Based on our findings, doctors and nurses may need to wear a fitted respirator even for routine care of flu patients as opposed to just the non-fitted, surgical face mask currently recommended."

The researchers determined that the majority of influenza virus in the air samples tested was found in small particles up to six feet from the patient's head. The small particles can float in the air for hours, travel relatively long distances and readily penetrate the non-fitted protective masks.

Bischoff said that future studies are required to establish person-to-person transmission of influenza and determine if super emitters spread the flu to more people, Medical News Today reports.

The study was published online in the January 31 edition of The Journal of Infectious Disease.