Ten years after Sars, now we have Mers

A deadly virus alarms scientists, as a new flu strain appears in China

Margaret Chan, director general of the World Health Organization, did not mince her words. The deadly Sars-like virus that has spread in recent months from the Middle East to Germany, France and the UK, killing more than half of those it has infected, is a "threat to the entire world".

Since it emerged in Saudi Arabia in September last year, the new virus has spread to 50 people in eight countries and claimed 30 lives. But it is not what it has done that is worrying – it is what it may do.

Addressing the World Health Assembly in Geneva last week, Dr Chan said: "We understand too little about this virus when viewed against the magnitude of its potential threat. Any new disease that is emerging faster than our understanding is never under control. These are alarm bells and we must respond. The novel coronavirus is not a problem that any single country can manage by itself."

Her words recall the panic that gripped the world when Sars – severe acute respiratory syndrome – appeared in 2003 and swept around the globe, infecting more than 8,000 people and causing 800 deaths. The WHO has called the new illness Mers – Middle East respiratory syndrome – reflecting its geographical origins. So far Mers has proved less infectious than Sars – but for how long?

The new illness is caused, as Sars was, by a coronavirus, the agent responsible for most common colds. But this is no ordinary cold. In cases seen so far, the Mers virus causes fever, pneumonia and breathing difficulties – the worst-affected victims drown in their own secretions.

Two of the three people who fell victim in the UK, after travelling from Saudi Arabia, were so ill they had to be treated on a machine that extracted blood from their body and oxygenated it artificially, to give their hearts and lungs a chance to recover.

Until now, all the known cases have occurred among patients with multiple health problems and low immunity. The virus has spread only within hospitals and health centres or among families where there has been close contact. There is, says the WHO, "no evidence of sustained human-to-human transmission".

As long as that remains the case, there is little need to worry. But as Dr Chan explained, we do not know where the virus originated – bats have been suggested, but not confirmed – or how people are getting infected. Nor do we know if the cases identified represent the tip of an iceberg of milder cases, or the whole iceberg.

While Mers is causing alarm in the Middle East and Europe, health experts in the Far East are worrying over a different threat – from a new strain of flu that could be a harbinger of the next pandemic.

H7N9 has been described as the "nastiest virus in humans in years". It is deadly, resistant to anti-flu drugs and poses a "serious threat" because of its potential to mutate and create a new pandemic strain, according to Professor John McCauley, director of the WHO's collaborating centre for flu surveillance in the UK.

There have been 132 laboratory confirmed cases and 37 deaths, says the WHO. The latest case is a six-year-old boy who became ill in Beijing on 21 May. The virus has spread to half a dozen provinces in China and to Taiwan but appears to have slowed in the past month.

Its source has not yet been identified, but a study published in The Lancet suggested H7N9 was a mix of at least four viruses that originated in ducks and chicken. Many of the cases started around Shanghai, which responded by closing poultry markets. A sharp fall in the number of new infections followed.

The big fear is of human-to-human transmission. There is no evidence that it has happened so far, but neither the WHO nor China has ruled it out. The Taiwanese case had no known exposure to poultry.

"This is one of the most lethal influenza viruses we have seen so far," said Keiji Fukuda, WHO assistant director general. "It is an unusually dangerous virus for humans."

Whenever a flu virus jumps from its normal host in birds or animals to humans, it sets alarm bells ringing. They are ringing now among scientists across the world.

Life and Style
ebookNow available in paperback
ebooks
ebookPart of The Independent’s new eBook series The Great Composers
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

    Ashdown Group: Technical Presales Consultant - London - £65,000 OTE.

    £65000 per annum: Ashdown Group: Technical Presales Engineer - central London ...

    Recruitment Genius: Physiotherapist / Sports Therapist

    £20000 - £50000 per annum: Recruitment Genius: A Physiotherapist / Sports Ther...

    Recruitment Genius: Sales Executive / Advisor

    £8 - £9 per hour: Recruitment Genius: Sales Executives / Advisors are required...

    Recruitment Genius: Warehouse Operative

    £14000 - £15000 per annum: Recruitment Genius: An opportunity has arisen for a...

    Day In a Page

    Homeless Veterans campaign: Donations hit record-breaking £1m target after £300,000 gift from Lloyds Bank

    Homeless Veterans campaign

    Donations hit record-breaking £1m target after huge gift from Lloyds Bank
    Flight MH370 a year on: Lost without a trace – but the search goes on

    Lost without a trace

    But, a year on, the search continues for Flight MH370
    Germany's spymasters left red-faced after thieves break into brand new secret service HQ and steal taps

    Germany's spy HQ springs a leak

    Thieves break into new €1.5bn complex... to steal taps
    International Women's Day 2015: Celebrating the whirlwind wit of Simone de Beauvoir

    Whirlwind wit of Simone de Beauvoir

    Simone de Beauvoir's seminal feminist polemic, 'The Second Sex', has been published in short-form for International Women's Day
    Mark Zuckerberg’s hiring policy might suit him – but it wouldn’t work for me

    Mark Zuckerberg’s hiring policy might suit him – but it wouldn’t work for me

    Why would I want to employ someone I’d be happy to have as my boss, asks Simon Kelner
    Confessions of a planespotter: With three Britons under arrest in the UAE, the perils have never been more apparent

    Confessions of a planespotter

    With three Britons under arrest in the UAE, the perils have never been more apparent. Sam Masters explains the appeal
    Russia's gulag museum 'makes no mention' of Stalin's atrocities

    Russia's gulag museum

    Ministry of Culture-run site 'makes no mention' of Stalin's atrocities
    The big fresh food con: Alarming truth behind the chocolate muffin that won't decay

    The big fresh food con

    Joanna Blythman reveals the alarming truth behind the chocolate muffin that won't decay
    Virginia Ironside was my landlady: What is it like to live with an agony aunt on call 24/7?

    Virginia Ironside was my landlady

    Tim Willis reveals what it's like to live with an agony aunt on call 24/7
    Paris Fashion Week 2015: The wit and wisdom of Manish Arora's exercise in high camp

    Paris Fashion Week 2015

    The wit and wisdom of Manish Arora's exercise in high camp
    8 best workout DVDs

    8 best workout DVDs

    If your 'New Year new you' regime hasn’t lasted beyond February, why not try working out from home?
    Paul Scholes column: I don't believe Jonny Evans was spitting at Papiss Cissé. It was a reflex. But what the Newcastle striker did next was horrible

    Paul Scholes column

    I don't believe Evans was spitting at Cissé. It was a reflex. But what the Newcastle striker did next was horrible
    Miguel Layun interview: From the Azteca to Vicarage Road with a million followers

    From the Azteca to Vicarage Road with a million followers

    Miguel Layun is a star in Mexico where he was criticised for leaving to join Watford. But he says he sees the bigger picture
    Frank Warren column: Amir Khan ready to meet winner of Floyd Mayweather v Manny Pacquiao

    Khan ready to meet winner of Mayweather v Pacquiao

    The Bolton fighter is unlikely to take on Kell Brook with two superstar opponents on the horizon, says Frank Warren
    War with Isis: Iraq's government fights to win back Tikrit from militants - but then what?

    Baghdad fights to win back Tikrit from Isis – but then what?

    Patrick Cockburn reports from Kirkuk on a conflict which sectarianism has made intractable