Featured Research

from universities, journals, and other organizations

Borne on the wing: Avian influenza risk in US wild songbirds mapped

Date:
July 11, 2010
Source:
National Science Foundation
Summary:
Scientists have discovered that 22 species of passerines -- songbirds and perching birds -- in the contiguous U.S. are carriers of low-pathogenicity avian influenza. Pathogenicity is the ability of a germ to produce an infectious disease in an organism. The prevalence of influenza in waterfowl has long been known. But the researchers' analysis indicates that the number of songbird species with low-pathogenicity avian influenza is greater than the number in eight other avian orders, including waterfowl.

Predicted number of cases of avian influenza in wild birds in the U.S. at the state scale.
Credit: Thomas B. Smith

Scientists have discovered that 22 species of passerines--songbirds and perching birds--in the contiguous U.S. are carriers of low-pathogenicity avian influenza. Pathogenicity is the ability of a germ to produce an infectious disease in an organism.

The researchers report their results in the journal BMC Infectious Diseases.

The research is supported by the joint National Institutes of Health (NIH)-National Science Foundation (NSF) Ecology of Infectious Diseases (EID) Program. At NSF, EID is co-funded by the Directorates for Biological Sciences and Geosciences.

The prevalence of influenza in waterfowl has long been known.

But the researchers' analysis of samples taken from 225 passerine species in 41 U.S. states indicates that the number of songbird species with low-pathogenicity avian influenza is greater than the number in eight other avian orders, including waterfowl.

"Avian influenza virus [AIV] is an important public health issue because pandemic influenza viruses in people have contained genes from viruses that infect birds," says Trevon Fuller, lead author of the paper and a biologist at the Center for Tropical Research at UCLA.

"Some AIV subtypes have periodically mutated from low pathogenicity to high pathogenicity forms that are lethal, for example, to poultry."

Since passerines share the same habitat as poultry, they may be more effective transmitters of this disease than aquatic birds to humans, Fuller says.

Analysis of the geographic distribution of AIV, says Thomas Smith, also a biologist at the Center for Tropical Research at UCLA and a co-author of the paper, "can identify areas where such 'reassortment' events might occur, and how high pathogenicity might travel if it enters wild bird populations in the U.S."

Modelling the number of AIV cases is important, says Sam Scheiner, NSF program director for EID, "because the rate of co-infection with multiple AIV subtypes increases with the number of cases."

Hotspots in the contiguous U.S. for AIV cases include the Mississippi River basin, with its shallow pools of water and wetlands conducive to the spread of the virus.

On a state scale, Minnesota is predicted to have the most cases of AIV. The virus has been introduced to Minnesota turkey farms by wild birds--some 135 times since 1968.

Emily Curd, a graduate student at the UCLA Center for Tropical Research, developed a technique to detect short fragments of influenza. It proved crucial to the research, says Smith.

Her efforts, he says, "made it possible to find the virus in the many samples collected by volunteer bird-banders."

The scientists also investigated the association between AIV cases in wild birds and 12 predictor variables--some of which measured agricultural and commercial activity--and climate.

Significant predictors of the number of AIV cases in wild birds per county were thaw date in spring; the percent of the county that is harvested cropland; and minimum temperature.

Thaw date explains the number of AIV cases because if a site thaws earlier, waterfowl may occupy an area sooner. More opportunities exist for adults to infect juveniles than if the site were covered by snow and ice until later.

The amount of harvest cropland was "highly significant," the biologists found. "Agricultural activity reduces the amount of natural habitat available to avian migrants," says Fuller. The birds become crowded together in smaller areas.

Minimum temperature also emerged as important for predicting AIV cases. AIV is known to survive for a longer time in colder conditions.

During a cool-weather 1984 outbreak in Pennsylvania, for example, the virus survived in barns for as long as 105 days.


Story Source:

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


Journal Reference:

  1. Trevon L Fuller, Sassan S Saatchi, Emily E Curd, Erin Toffelmier, Henri A Thomassen, Wolfgang Buermann, David F DeSante, Mark P Nott, James F Saracco, C J Ralph, John D Alexander, John P Pollinger, Thomas B Smith. Mapping the risk of avian influenza in wild birds in the US. BMC Infectious Diseases, 2010; 10 (1): 187 DOI: 10.1186/1471-2334-10-187

Cite This Page:

National Science Foundation. "Borne on the wing: Avian influenza risk in US wild songbirds mapped." ScienceDaily. ScienceDaily, 11 July 2010. <www.sciencedaily.com/releases/2010/07/100709104122.htm>.
National Science Foundation. (2010, July 11). Borne on the wing: Avian influenza risk in US wild songbirds mapped. ScienceDaily. Retrieved September 14, 2014 from www.sciencedaily.com/releases/2010/07/100709104122.htm
National Science Foundation. "Borne on the wing: Avian influenza risk in US wild songbirds mapped." ScienceDaily. www.sciencedaily.com/releases/2010/07/100709104122.htm (accessed September 14, 2014).

Share This



More Plants & Animals News

Sunday, September 14, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) — New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
Powered by NewsLook.com
Shocker: Journalists Are Utterly Addicted To Coffee

Shocker: Journalists Are Utterly Addicted To Coffee

Newsy (Sep. 13, 2014) — A U.K. survey found that journalists consumed the most amount of coffee, but that's only the tip of the coffee-related statistics iceberg. Video provided by Newsy
Powered by NewsLook.com
'Magic Mushrooms' Could Help Smokers Quit

'Magic Mushrooms' Could Help Smokers Quit

Newsy (Sep. 11, 2014) — In a small study, researchers found that the majority of long-time smokers quit after taking psilocybin pills and undergoing therapy sessions. Video provided by Newsy
Powered by NewsLook.com
Spinosaurus Could Be First Semi-Aquatic Dinosaur

Spinosaurus Could Be First Semi-Aquatic Dinosaur

Newsy (Sep. 11, 2014) — New research has shown that the Spinosaurus, the largest carnivorous dinosaur, might have been just as well suited for life in the water as on land. 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