Featured Research

from universities, journals, and other organizations

Major Mid-century Influenza Epidemics Caused By Novel Hybrid Viruses

Date:
March 3, 2008
Source:
Public Library of Science
Summary:
Reassortment of the influenza A virus occurs frequently throughout its evolutionary history, according to a new study in PLoS Pathogens. The researchers found that the severe influenza epidemics of 1947 and 1951 were caused by genetic reassortment events in which two human influenza viruses of the same H1N1 strain exchanged genetic material, producing a new hybrid virus in both cases.

This transmission electron micrograph (TEM) of an ultra-thin specimen revealed some of the ultrastructural morphologic features seen in 1918 influenza virus virions.
Credit: Cynthia Goldsmith

Reassortment of the influenza A virus occurs frequently throughout its evolutionary history. Researchers at Pennsylvania State University and the National Institute of Health used an evolutionary analysis of influenza viruses sampled from 1918 -- 2005 to investigate the influenza viruses that cause seasonal epidemics in humans, particularly those where mortality was unusually high.

Specifically, the researchers found that the severe influenza epidemics of 1947 and 1951 were caused by genetic reassortment events in which two human influenza viruses of the same H1N1 strain exchanged genetic material, producing a new hybrid virus in both cases.

It has been a mystery why unusually severe epidemics of influenza occur from time to time, such as in 1947 and 1951, when illness and mortality rates exceeded standard epidemic levels. The standard model of human influenza virus evolution holds that major influenza pandemics, the largest of which occurred in 1918, are caused by reassortment between human and avian influenza viruses. But seasonal influenza epidemics, which occur each winter in the United States, do not involve the reassortment of genetic material.

These new findings suggest that the evolution of seasonal influenza is more complex than previously thought, and that multiple forms of the same strain co-circulate and re-assort within a single population, rapidly generating genetically novel viruses with the potential to ignite major epidemics. It is therefore critical that intensive surveillance is undertaken to capture the full extent of influenza genetic diversity that co-circulates at a given time, particularly as an aid to vaccine design.

Journal reference: Nelson MI, Viboud C, Simonsen L, Bennett RT, Griesemer SB, et al. (2008) Multiple Reassortment Events in the Evolutionary History of H1N1 Influenza A Virus Since 1918. PLoS Pathog 4(2): e1000012. doi:10.1371/journal.ppat.1000012 http://www.plospathogens.org/doi/ppat.1000012


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Cite This Page:

Public Library of Science. "Major Mid-century Influenza Epidemics Caused By Novel Hybrid Viruses." ScienceDaily. ScienceDaily, 3 March 2008. <www.sciencedaily.com/releases/2008/02/080229075244.htm>.
Public Library of Science. (2008, March 3). Major Mid-century Influenza Epidemics Caused By Novel Hybrid Viruses. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2008/02/080229075244.htm
Public Library of Science. "Major Mid-century Influenza Epidemics Caused By Novel Hybrid Viruses." ScienceDaily. www.sciencedaily.com/releases/2008/02/080229075244.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
WHO: Ebola Vaccine Trials to Start a in January

WHO: Ebola Vaccine Trials to Start a in January

AP (Oct. 21, 2014) Tens of thousands of doses of experimental Ebola vaccines could be available for "real-world" testing in West Africa as soon as January as long as they are deemed safe in soon to start trials, the World Health Organization said Tuesday. (Oct. 21) Video provided by AP
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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