Navigation Links
Size of airborne flu virus impacts risk, Virginia Tech researchers say

A parent's wise advice to never go to a hospital unless you want to get sick may be gaining support from scientific studies on a specific airborne virus.

The results of a Virginia Tech study by environmental engineers and a virologist on the risk of airborne infection in public places from concentrations of influenza A viruses is appearing today in the on-line, Feb. 2 issue of the United Kingdom's Journal of the Royal Society Interface.

Linsey Marr, associate professor of civil and environmental engineering at Virginia Tech, and her colleagues, Wan Yang, of Blacksburg, Va., one of her graduate students, and Elankumaran Subbiah, a virologist in the biomedical sciences and pathobiology department of the Virginia-Maryland Regional College of Veterinary Medicine, conducted their research in a health center, a daycare facility, and onboard airplanes.

"The relative importance of the airborne route in influenza transmissionin which tiny respiratory droplets from infected individuals are inhaled by othersis not known," Marr, who received a National Science Foundation CAREER Award to pinpoint sources of unhealthy air pollutants, said.

What is known is that influenza A viruses are "transmitted through direct contact, indirect contact, large respiratory droplets, and aerosols that are left behind by the evaporation of larger droplets," they reported in the journal. "The aerosol transmission route is particularly controversial since there is scant proof of infection mediated by virus-laden aerosols, partly due to the difficulties in studies involving human subjects and partly due to the challenges in detecting influenza A viruses in ambient air."

What happens is an infected person might cough or sneeze or just be engaged in conversation, and release the viruses into the air. However, these aerosols are quickly diluted to very low concentrations by the surrounding air.

Marr said, "Few studies have measured actual concentrations of influenza A viruses in air and determined the size of influenza-laden particles. Size is important because it determines how long the particles will remain suspended in the air before being removed due to the forces of gravity or other processes."

To conduct their studies, the Virginia Tech researchers collected samples from a waiting room of a health care center, two toddlers' rooms and one babies' area of a daycare center, as well as three cross-country flights between Roanoke, Va., and San Francisco, Ca. They collected 16 samples between Dec. 10, 2009 and Apr. 22, 2010.

"Half of the samples were confirmed to contain aerosolized influenza A viruses," Marr said. "In the others, it is possible that no infected individuals were present."

Marr added, "The average concentration was 16,000 viruses per cubic meter of air, and the majority of the viruses were associated with fine particles, less than 2.5 micrometers, which can remain suspended for hours. Given these concentrations, the amount of viruses a person would inhale over one hour would be adequate to induce infection."

Subbiah indicated that most studies of airborne transmission of influenza viruses in animals examined the ability of infected animals to transmit the infection to susceptible in-contact animals. How the ambient environment affects the virus after release from the infected host until it reaches the recipient host is relatively unknown. Results of the study show that under defined conditions of humidity and temperature, viruses may remain suspended in air.

Incorporating the concentrations of influenza A viruses and breathing rates, Marr and her colleagues estimated the inhalation dose incurred by someone in the same room and concluded that it was sufficient to induce infection.

"As a whole," the three authors concluded in the Journal of the Royal Society Interface, "our results provide quantitative support for the possibility of airborne transmission of influenza in indoor environments."


Contact: Lynn Nystrom
Virginia Tech

Related biology technology :

1. Tiny sensors tucked into cell phones could map airborne toxins in real time
2. Researchers visualize herpes virus tactical maneuver
3. NOVAVAX and University of Massachusetts Medical School Publish Preclinical Safety and Efficacy Study of a Respiratory Syncytial Virus (RSV) Virus-like Particle (VLP) Vaccine Candidate
4. USDA scientists discover how foot-and-mouth disease virus begins infection in cattle
5. Bad Virus Put to Good Use: Breakthrough Batteries
6. Chimerix Presents Update on CMX001 Development to the World Health Organization Advisory Committee on Variola Virus Research
7. New Finding of Rise in H5N1 Virus (Avian Flu) Replikin Count
8. First Duplex Test for Parvovirus B19 and Hepatitis A Virus Increases Safety of Human Plasma and Plasma Products
9. Researchers sequence genome of mosquito that spreads West Nile virus
10. Santaris Pharma A/S Advances miravirsen, the First microRNA-Targeted Drug to Enter Clinical Trials, Into Phase 2 to Treat Patients Infected With Hepatitis C Virus
11. STEMCELL Technologies is Proud to Announce STEMcircles™, a Virus-Free Technology for Reprogramming Cells
Post Your Comments:
Related Image:
Size of airborne flu virus impacts risk, Virginia Tech researchers say
(Date:11/24/2015)... -- SHPG ) announced today that Jeff Poulton ... th Annual Healthcare Conference in New York City ... EST (1:30 p.m. GMT). --> SHPG ) announced today ... the Piper Jaffray 27 th Annual Healthcare Conference in ... 2015, at 8:30 a.m. EST (1:30 p.m. GMT). --> ...
(Date:11/24/2015)... CITY , Nov. 24, 2015 /PRNewswire/ - ... "Company") announced today that the remaining 11,000 post-share ... Share Purchase Warrants (the "Series B Warrants") subject ... were exercised on November 23, 2015, which will ... Shares.  After giving effect to the issuance of ...
(Date:11/24/2015)... ... 24, 2015 , ... InSphero AG, the leading supplier of easy-to-use solutions for ... Aregger to serve as Chief Operating Officer. , Having joined InSphero in ... and was promoted to Head of InSphero Diagnostics in 2014. There she ...
(Date:11/24/2015)... Capricor Therapeutics, Inc. (NASDAQ: ... development and commercialization of first-in-class therapeutics, today announced that ... scheduled to present at the 2015 Piper Jaffray Healthcare ... at The Lotte New York Palace Hotel in ... . --> . ...
Breaking Biology Technology:
(Date:10/29/2015)... Oct. 29, 2015   MedNet Solutions , an ... spectrum of clinical research, is pleased to announce that ... Association (MHTA) as one of only three finalists for ... – Small and Growing" category. The Tekne Awards honor ... shown superior technology innovation and leadership. ...
(Date:10/29/2015)... NXTD ) ("NXT-ID" or ... the growing mobile commerce market and creator of ... leading marketplace to discover and buy innovative technology ... on StackSocial for this holiday season.   ... a biometric authentication company focused on the growing ...
(Date:10/26/2015)... India , October 26, 2015 ... --> adds ... 2015 to 2021 as well as ... 2015-2019 research reports to its collection ... . --> ...
Breaking Biology News(10 mins):