Gene sleuths trace world cholera pandemic to Bangladesh

A cholera pandemic that has swept poor countries in three waves over nearly four decades has been traced to a bacterial strain that first emerged in Bangladesh, scientists reported on Wednesday.

The current pandemic is the seventh since cholera, a water- and food-borne diarrhoeal disease caused by the Vibrio cholerae bug, emerged nearly two centuries ago.

Gene sequencing of 154 samples of V. cholerae taken from patients around the world show today's pandemic can be traced to an initial outbreak of cholera in the Bay of Bengal in 1975, the investigators said.

In 1982, the strain, known as El Tor, acquired genes making it resistant to antibiotics. As a result, successive waves of the disease spread around the world, propagated from the original source.

The new probe, published in the British journal Nature, points to the likely role of modern travel in transmitting the bacteria - and the importance of the Gulf of Bengal as a "reservoir," or source from which the germ can always be transmitted.

"Our research shows the importance of global transmission events in the spread of cholera," said Julian Parkhill of Britain's Wellcome Trust Sanger Institute.

"This goes against previous beliefs that cholera always rises from local strains, and provides useful information in understanding cholera outbreaks."

Cholera affects between three and five million people a year, with 100,000-120,000 deaths annually.

The latest prominent outbreak occurred in Haiti in October 2010 in conditions of poor sanitation after the country's earthquake.

In June this year, US investigators determined that the bacteria had been brough to Haiti by UN peacekeepers from Nepal.

The study is the latest example of the power of genomics - the unravelling of the DNA code of an organism, whose mutations enable scientists to draw up a "family tree" to show when and where the bug changed.

El Tor probably evolved in the 1950s, said the paper.

ri/ss

 

PROMOTED VIDEO
Life and Style
ebooksA superb mix of recipes serving up the freshest of local produce in a delicious range of styles
Life and Style
ebooksFrom the lifespan of a slug to the distance to the Sun: answers to 500 questions from readers
Sport
David Moyes gets soaked
sport Moyes becomes latest manager to take part in the ALS challenge
Life and Style
techCould new invention save millions in healthcare bills?
Voices
A meteor streaks across the sky during the Perseid Meteor Shower at a wind farm near Bogdanci, south of Skopje, Macedonia, in the early hours of 13 August
voicesHagel and Dempsey were pure Hollywood. They only needed Tom Cruise, says Robert Fisk
News
peopleEnglishman managed quintessential Hollywood restaurant Chasen's
Life and Style
food + drinkHarrods launches gourmet food qualification for staff
Arts and Entertainment
Michael Flatley prepares to bid farewell to the West End stage
danceMichael Flatley hits West End for last time alongside Team GB World champion Alice Upcott
News
Members and supporters of the lesbian, gay, bisexual, transgender (LGBT) community walk with a rainbow flag during a rally in July
i100
Life and Style
Black Ivory Coffee is made using beans plucked from elephants' waste after ingested by the animals
food + drinkFirm says it has created the "rarest" coffee in the world
Arts and Entertainment
Jamie T plays live in 2007 before going on hiatus from 2010
arts + entsSinger-songwriter will perform on the Festival Republic Stage
Life and Style
food + drinkThese simple recipes will have you refreshed within minutes
News
Jermain Defoe got loads of custard
i100
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Helpdesk Team Leader / Manager

    £45000 per annum + pension,medical: Ashdown Group: A successful & reputable gl...

    IT Systems Manager

    £40000 - £45000 per annum + pension, healthcare,25 days: Ashdown Group: An est...

    IT Project Manager

    £35000 per annum + £5k bonus, car: Ashdown Group: A successful business that h...

    IT Infrastructure Project Manager

    £40000 per annum: Ashdown Group: A large and well established business is look...

    Day In a Page

    All this talk of an ‘apocalyptic’ threat is simply childish

    Robert Fisk: All this talk of an ‘apocalyptic’ threat is simply childish

    Chuck Hagel and Martin Dempsey were pure Hollywood. They only needed Tom Cruise
    Mafia Dons: is the Camorra in control of the Granite City?

    Mafia Dons: is the Camorra in control of the Granite City?

    So claims an EU report which points to the Italian Mob’s alleged grip on everything from public works to property
    Emmys look set to overhaul the Oscars as Hollywood’s prize draw

    Emmys look set to overhaul the Oscars as Hollywood’s prize draw

    Once the poor relation, the awards show now has the top stars and boasts the best drama
    French connection: After 1,300 years, there’s a bridge to Mont Saint-Michel

    French connection: After 1,300 years, there’s a bridge to Mont Saint-Michel

    The ugly causeway is being dismantled, an elegant connection erected in its place. So everyone’s happy, right?
    Radio 1 to hire 'YouTube-famous' vloggers to broadcast online

    Radio 1’s new top ten

    The ‘vloggers’ signed up to find twentysomething audience
    David Abraham: Big ideas for the small screen

    David Abraham: Big ideas for the small screen

    A blistering attack on US influence on British television has lifted the savvy head of Channel 4 out of the shadows
    Match of the Day at 50: Show reminds us that even the most revered BBC institution may have a finite lifespan – thanks to the opposition

    Tom Peck on Match of the Day at 50

    The show reminds us that even the most revered BBC institution may have a finite lifespan – thanks to the opposition
    Air strikes? Talk of God? Obama is following the jihadists’ script

    Air strikes? Talk of God? Obama is following the jihadists’ script

    The President came the nearest he has come yet to rivalling George W Bush’s gormless reaction to 9/11 , says Robert Fisk
    Ebola outbreak: Billy Graham’s son declares righteous war on the virus

    Billy Graham’s son declares righteous war on Ebola

    A Christian charity’s efforts to save missionaries trapped in Africa by the crisis have been justifiably praised. But doubts remain about its evangelical motives
    Jeremy Clarkson 'does not see a problem' with his racist language on Top Gear, says BBC

    Not even Jeremy Clarkson is bigger than the BBC, says TV boss

    Corporation’s head of television confirms ‘Top Gear’ host was warned about racist language
    Nick Clegg the movie: Channel 4 to air Coalition drama showing Lib Dem leader's rise

    Nick Clegg the movie

    Channel 4 to air Coalition drama showing Lib Dem leader's rise
    Philip Larkin: Misogynist, racist, miserable? Or caring, playful man who lived for others?

    Philip Larkin: What will survive of him?

    Larkin's reputation has taken a knocking. But a new book by James Booth argues that the poet was affectionate, witty, entertaining and kind, as hitherto unseen letters, sketches and 'selfies' reveal
    Madame Tussauds has shown off its Beyoncé waxwork in Regent's Park - but why is the tourist attraction still pulling in the crowds?

    Waxing lyrical

    Madame Tussauds has shown off its Beyoncé waxwork in Regent's Park - but why is the tourist attraction still pulling in the crowds?
    Texas forensic astronomer finally pinpoints the exact birth of impressionism

    Revealed (to the minute)

    The precise time when impressionism was born
    From slow-roasted to sugar-cured: how to make the most of the British tomato season

    Make the most of British tomatoes

    The British crop is at its tastiest and most abundant. Sudi Pigott shares her favourite recipes