Featured Research

from universities, journals, and other organizations

Human Nose Too Cold For Bird Flu, Says New Study

Date:
May 15, 2009
Source:
Imperial College London
Summary:
Avian influenza viruses do not thrive in humans because the temperature inside a person's nose is too low, according to new research. The authors of the study say this may be one of the reasons why bird flu viruses do not cause pandemics in humans easily.

Avian influenza viruses do not thrive in humans because the temperature inside a person's nose is too low, according to research published May 14 in the journal PLoS Pathogens. The authors of the study, from Imperial College London and the University of North Carolina, say this may be one of the reasons why bird flu viruses do not cause pandemics in humans easily.

There are 16 subtypes of avian influenza and some can mutate into forms that can infect humans, by swapping proteins on their surface with proteins from human influenza viruses.

Today's study shows that normal avian influenza viruses do not spread extensively in cells at 32 degrees Celsius, the temperature inside the human nose. The researchers say this is probably because the viruses usually infect the guts of birds, which are warmer, at 40 degrees Celsius. This means that avian flu viruses that have not mutated are less likely to infect people, because the first site of infection in humans is usually the nose. If a normal avian flu virus infected a human nose, the virus would not be able to grow and spread between cells, so it would be less likely to damage cells and cause respiratory illness.

The researchers also found that when they created a mutated human influenza virus by adding a protein from the surface of an avian influenza virus, this mutated virus struggled to thrive at 32 degrees Celsius. This suggests that if a new human influenza strain evolved by adopting proteins from an avian influenza virus, this would need to undergo further changes in order to adapt to the conditions in the human body.

The researchers reached their conclusions by growing cells from the human airway and infecting them with different human and avian influenza viruses, including H5N1, to see how well the viruses grew and spread. The human influenza viruses grew equally well in the cells whether they were maintained at 37 degrees Celsius, our core body temperature, or at 32 degrees Celsius, the temperature of the nose. In contrast, the four avian influenza viruses tested grew well at 37 degrees Celsius but grew very slowly at 32 degrees Celsius.

When the researchers added proteins from an avian influenza virus to a human influenza virus, the human influenza virus also grew slowly and struggled to replicate at 32 degrees Celsius.

As viruses kill the cells they infect, the researchers also measured the extent of cell death in the model. This showed that at 32 degrees Celsius, far fewer cells died as a result of infection with avian influenza compared with human influenza, supporting the idea that the avian virus could not thrive at that temperature.

Professor Wendy Barclay, one of the authors of the study from the Division of Investigative Science at Imperial College London, said: "Bird viruses are out there all the time but they can only cause pandemics when they undergo certain changes. Our study gives vital clues about what kinds of changes would be needed in order for them to mutate and infect humans, potentially helping us to identify which viruses could lead to a pandemic.

"It would be impossible to develop vaccines against all 16 subtypes of avian flu, so we need to prioritise. By studying a range of different viruses in systems like this one we can look for warnings that they are already beginning to make the kinds of genetic changes in nature that mean they could be poised to jump into humans; animal viruses that spread well at low temperatures in these cultures could be more likely to cause the next pandemic than those which are restricted," added Professor Barclay.

The research was funded by the Medical Research Council in the UK and by the NIH in the USA.


Story Source:

The above story is based on materials provided by Imperial College London. Note: Materials may be edited for content and length.


Cite This Page:

Imperial College London. "Human Nose Too Cold For Bird Flu, Says New Study." ScienceDaily. ScienceDaily, 15 May 2009. <www.sciencedaily.com/releases/2009/05/090514222019.htm>.
Imperial College London. (2009, May 15). Human Nose Too Cold For Bird Flu, Says New Study. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2009/05/090514222019.htm
Imperial College London. "Human Nose Too Cold For Bird Flu, Says New Study." ScienceDaily. www.sciencedaily.com/releases/2009/05/090514222019.htm (accessed July 25, 2014).

Share This




More Health & Medicine News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins