News / Health

Study Links Flu Pandemics to La Niña

New varieties emerge when virus-carrying birds change migration path

Health workers pack dead chicken at a wholesale poultry market in Hong Kong, on Dec. 21, 2011, after a bird flu scare in China.
Health workers pack dead chicken at a wholesale poultry market in Hong Kong, on Dec. 21, 2011, after a bird flu scare in China.

Multimedia

Audio
Art Chimes

A newly-identified link between pandemic flu and the weather phenomenon known as La Niña, may one day permit advance warnings of severe influenza outbreaks.

Most of the time, influenza is a temporary annoyance. But every so often a super flu bug comes along, killing millions and sickening many more.

Jeffrey Shaman, of the Columbia University School of Public Health, notes there were four documented flu pandemics in the past century.

"When we look at those four events, we see that all four of them began directly after a La Niña event in the Pacific," he says.



La Niña is a periodic cooling of Pacific ocean waters that triggers changes in global weather patterns. Among other things, that altered weather disrupts bird migrations.

Birds can carry flu virus, and when their migratory patterns change, they can come into contact with other avian species they don't normally meet - birds which might carry a different strain of flu virus.

In the process, the viruses’ genetic material can get intermingled to create new influenza strains - in a process known as reassortment.

"And it's this reassortment, this creation of new sub-types that takes place - and we think it's in the bird population - that generates, potentially, these pandemic strains that can infect humans and to which most of the world's population will be susceptible," Shaman says.

La Niña events happen every few years, and most are not followed by a pandemic. But because the risk of a pandemic appears to increase after a La Niña, the next step for researchers is to get a better understanding of how birds and the flu viruses they carry are affected.

One result, Shaman says, may be the ability to improve prediction of an influenza pandemic.

"That's the thing that's exciting about it," he says. "I mean, it offers this sort of tantalizing possibility that you can say, we have a La Niña coming, we need to make these preparations because we know there's an increased likelihood that a pandemic flu strain could arise and infect humans."

But Shaman cautions that more research is needed before that kind of prediction becomes possible. His research paper is published in the Proceedings of the National Academy of Sciences.

You May Like

Key Al-Shabab Commander Captured

Zakariye Ismail Hersi was captured in a raid Saturday morning in the town of El Wak near the border with Kenya More

Relations Between Pakistan, Afghanistan Key to Fighting Taliban

A Pakistani official tells VOA that anti-terrorism campaign has resulted in improved counter-terrorism cooperation with Afghanistan More

Malaysia PM Tours Flooded Areas

Najib Razak announces nearly $145 million for flood-victim relief nationwide, which will be administered by the National Security Council More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Estimates Rising of Foreign Fighters in Iraq, Syriai
X
Jeff Seldin
December 24, 2014 11:38 PM
Foreign fighters are making more of a mark on the battles raging across Syria and Iraq than initially thought. VOA's Jeff Seldin has more.
Video

Video Estimates Rising of Foreign Fighters in Iraq, Syria

Foreign fighters are making more of a mark on the battles raging across Syria and Iraq than initially thought. VOA's Jeff Seldin has more.
Video

Video Russians Head Into Holiday Facing Economic Malaise

Russian preparations for the New Year holiday are clouded by economic recession and a tumbling currency, the ruble. Nonetheless, people in the Russian capital appear to be in a festive mood. VOA's Daniel Schearf reports from Moscow.
Video

Video Mombasa in Holiday Tourism Slump Due to Security Fears

Kenya's usually popular beachside tourist destination of Mombasa is seeing a much slower holiday season this year due to fears of insecurity as the country has suffered from a string of terror attacks linked to Somali militants. Mohammed Yusuf reports for VOA on how businessmen and tourists feel about the situation.
Video

Video For Somalis, 2014 Marked by Political Instability Within Government

While Somalia has long been torn apart by warfare and violence, this year one of the country's biggest challenges has come from within the government, as political infighting curtails the country's progress, threatens security gains and disappoints the international community. VOA's Gabe Joselow report.
Video

Video US Political Shift Could Affect Iran Nuclear Talks

Secretary of State John Kerry’s efforts to resolve Iran’s nuclear crisis are continuing into 2015 after Iran and six world powers failed to agree by a November deadline. U.S. domestic politics, however, could complicate efforts to reach a deal in the new year. VOA State Department correspondent Pam Dockins has the story.
Video

Video NYSE: The Icon of Capitalism

From its humble beginnings in 1792 to its status as an economic bellweather for the world, the New York Stock Exchange is an integral part of the story of America. VOA’s Bernard Shusman reports from Wall Street.
Video

Video Islamic State Emergence Transforms Syria and Iraq in 2014

The emergence of the Islamic State in Iraq and Syria as a potent force in early 2014 changed the dynamics of the region. Their brutal methods - including executions and forced slavery - horrified the international community, drawing Western forces into the conflict. It also splintered the war in Syria, where more than 200,000 Syrians have died in the conflict. VOA’s Henry Ridgwell looks back at a deadly year in the region -- and what 2015 may hold.
Video

Video Massive Study Provides Best Look at Greenland Ice Loss Yet

The Greenland ice sheet is melting faster than predicted, according to a new study released in the Proceedings of the National Academic of Sciences that combines NASA satellite data and aerial missions. As VOA’s Rosanne Skirble reports, the finding means coastal communities worldwide could be at greater risk, sooner, from the impact of rising seas.
Video

Video US Marines, Toys for Tots Bring Christmas Joy

Christmas is a time for giving in the United States, especially to young children who look forward to getting presents. But some families don't have money to buy gifts. For nearly 70 years, a U.S. Marines-sponsored program has donated toys and distributed them to underprivileged children during the holiday season. VOA's Deborah Block tells us about the annual Toys for Tots program.
Video

Video France Rocked by Attacks as Fear of ISIS-Inspired Terror Grows

Eleven people were injured, two seriously, when a man drove his car into crowds of pedestrians Sunday night in the French city of Dijon, shouting ‘God is Great’ in Arabic. It’s the latest in a series of apparent ‘lone-wolf’ terror attacks in the West. Henry Ridgwell looks at the growing threat of attacks, which security experts say are likely inspired by the so-called "Islamic State" terror group.

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More

All About America

AppleAndroid