Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Patients can emit small, influenza-containing particles into the air during routine care

31.01.2013
A new study suggests that patients with influenza can emit small virus-containing particles into the surrounding air during routine patient care, potentially exposing health care providers to influenza.

Published in The Journal of Infectious Diseases, the findings raise the possibility that current influenza infection control recommendations may not always be adequate to protect providers from influenza during routine patient care in hospitals.

Werner E. Bischoff, MD, PhD, and colleagues from the Wake Forest School of Medicine in North Carolina screened 94 patients for flu-like symptoms during the 2010-2011 influenza season. Study participants had been admitted to the emergency department (52 patients) or an inpatient care unit (42 patients) of Wake Forest Baptist Medical Center, where vaccination for influenza is mandatory for health care providers.

Nasopharyngeal swabs were collected from each patient. Samples were analyzed by rapid testing and by PCR analysis. Air samples were obtained by placing three six-stage air samplers from within 1 foot, 3 feet, and 6 feet of patients. No aerosol-generating procedures—such as bronchoscopy, sputum induction, intubation, or cardiopulmonary resuscitation—were conducted while air sampling took place. During air sampling, the number of patients' coughs and sneezes were counted and assessed for severity. Patients also completed a questionnaire at admission to report symptoms and the number of days they were sick.

Of the 94 patients enrolled, 61 patients (65 percent) tested positive for influenza virus. Twenty-six (43 percent) released influenza virus into the air. Five patients (19 percent) emitted up to 32 times more virus than others. This group of patients with influenza, described by the researchers as "super-emitters," suggested that some patients may be more likely to transmit influenza than others. High concentration of influenza virus released into the air was associated with high viral loads in nasopharyngeal samples. Patients who emitted more virus also reported greater severity of illness.

The current belief is that influenza virus is spread primarily by large particles traveling up to a maximum of 3 to 6 feet from an infected person. Recommended precautions for health providers focus on preventing transmission by large droplets and following special instructions during aerosol-generating procedures. In this study, Dr. Bischoff and his team discovered that the majority of influenza virus in the air samples analyzed was found in small particles during non-aerosol-generating activities up to a 6-foot distance from the patient's head, and that concentrations of virus decreased with distance. The study addressed only the presence of influenza-containing particles near patients during routine care, not the actual transmission of influenza infection to others.

Fitted respirators are currently required for health care providers during aerosol-generating procedures with patients. During routine, non-aerosol-generating patient care, the current precautions recommend that providers wear a non-fitted face mask. Based on their findings, Dr. Bischoff and investigators are concerned that providers may still be exposed to infectious dosages of influenza virus up to 6 feet from patients with small wide-spreading particles potentially exceeding the current suggested exposure zones.

These findings suggest that current infection control recommendations may need to be reevaluated, the study authors concluded. The detection of "super-emitters" raises concerns about how individuals with high viral load may impact the spread of influenza, they noted. "Our study offers new evidence of the natural emission of influenza and may provide a better understanding of how to best protect health care providers during routine care activities," the study authors wrote. However, studies of influenza virus transmission will be necessary before the role of super-emitters can be firmly established, they noted.

In an accompanying editorial, Caroline Breese Hall, MD, from the University of Rochester School of Medicine and Dentistry in New York, highlighted the importance of a better understanding of influenza transmission as global travel has increased the likelihood of a rapid worldwide influenza outbreak. Although the study did not show that influenza transmission actually occurred, Dr. Hall noted, the findings "question the traditional belief that influenza is primarily spread by close contact with an infected person or by direct contact with infectious secretions."

While the study adds to the current understanding of the risks of influenza infection among patients and health providers, the findings also help define questions that still need to be answered, Dr. Hall noted. (Editor's Note: Dr. Hall died on Dec. 10, 2012, at the age of 73, shortly after completion of the editorial accompanying this study.)

Whatever protective equipment or infection control practices are used for preventing influenza transmission, vaccination of health providers remains a fundamental and key part of protecting them from influenza, noted Dr. William Schaffner, professor medicine and chair of the department of preventive medicine at Vanderbilt University School of Medicine in Nashville, Tenn., who was not involved with the study. "Influenza vaccination, although not perfect, is the best tool we have to protect health care workers—and their patients—from influenza illness."

Fast Facts:

1) Researchers found that patients with influenza can emit small, influenza virus-containing particles into the surrounding air during routine patient care, potentially exposing health care providers to influenza virus up to 6 feet away from infected patients.

2) Five patients (19 percent) in study were "super-emitters" who emitted up to 32 times more virus than others. Patients who emit a higher concentration of influenza virus also reported greater severity of illness.

3) The findings suggest that more research on how influenza is transmitted is needed and that current influenza infection control recommendations for health providers may need to be reevaluated.

The study and the accompanying editorial are available online. They are embargoed until 12:01 a.m. EST on Thursday, Jan. 31, 2013:

Published continuously since 1904, The Journal of Infectious Diseases is the premier global journal for original research on infectious diseases. The editors welcome major articles and brief reports describing research results on microbiology, immunology, epidemiology, and related disciplines, on the pathogenesis, diagnosis, and treatment of infectious diseases; on the microbes that cause them; and on disorders of host immune responses. The journal is an official publication of the Infectious Diseases Society of America (IDSA). Based in Arlington, Va., IDSA is a professional society representing nearly 10,000 physicians and scientists who specialize in infectious diseases.

Jerica Pitts | EurekAlert!
Further information:
http://www.idsociety.org

More articles from Health and Medicine:

nachricht New evidence: How amino acid cysteine combats Huntington's disease
27.07.2016 | Johns Hopkins Medicine

nachricht Cord blood outperforms matched, unrelated donor in bone marrow transplant
27.07.2016 | University of Colorado Anschutz Medical Campus

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Self-assembling nano inks form conductive and transparent grids during imprint

Transparent electronics devices are present in today’s thin film displays, solar cells, and touchscreens. The future will bring flexible versions of such devices. Their production requires printable materials that are transparent and remain highly conductive even when deformed. Researchers at INM – Leibniz Institute for New Materials have combined a new self-assembling nano ink with an imprint process to create flexible conductive grids with a resolution below one micrometer.

To print the grids, an ink of gold nanowires is applied to a substrate. A structured stamp is pressed on the substrate and forces the ink into a pattern. “The...

Im Focus: The Glowing Brain

A new Fraunhofer MEVIS method conveys medical interrelationships quickly and intuitively with innovative visualization technology

On the monitor, a brain spins slowly and can be examined from every angle. Suddenly, some sections start glowing, first on the side and then the entire back of...

Im Focus: Newly discovered material property may lead to high temp superconductivity

Researchers at the U.S. Department of Energy's (DOE) Ames Laboratory have discovered an unusual property of purple bronze that may point to new ways to achieve high temperature superconductivity.

While studying purple bronze, a molybdenum oxide, researchers discovered an unconventional charge density wave on its surface.

Im Focus: Mapping electromagnetic waveforms

Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.

Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...

Im Focus: Continental tug-of-war - until the rope snaps

Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases

Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

GROWING IN CITIES - Interdisciplinary Perspectives on Urban Gardening

15.07.2016 | Event News

SIGGRAPH2016 Computer Graphics Interactive Techniques, 24-28 July, Anaheim, California

15.07.2016 | Event News

Partner countries of FAIR accelerator meet in Darmstadt and approve developments

11.07.2016 | Event News

 
Latest News

New study reveals where MH370 debris more likely to be found

27.07.2016 | Earth Sciences

Dirty to drinkable

27.07.2016 | Materials Sciences

Exploring one of the largest salt flats in the world

27.07.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>