* New strain called Sydney 2012 first seen in Australia
* Strain dominates in UK, seen in France, Japan, N.Zealand
* Norovirus infection causes projectile vomiting, diarrhoea
By Kate Kelland
LONDON, Jan 9 (Reuters) – A new strain of the winter
vomiting disease norovirus has spread to France, New Zealand and
Japan from Australia and is overtaking all others to become the
dominant strain in Britain, health officials said on Wednesday.
The norovirus variant, known as Sydney 2012, was identified
in a scientific paper last week and Britain’s Health Protection
Agency (HPA) said genetic testing showed it was now causing more
cases in England and Wales than other strains.
Sydney 2012 does not carry worse symptoms than others but,
like other norovirus strains, it can cause violent and
projectile vomiting, diarrhoea and sometimes fevers, headaches
and stomach cramps.
Norovirus cases have risen earlier than expected this winter
in Britain, across Europe, Japan and other parts of the world.
Although norovirus mostly causes just a few days of
sickness, it is responsible for millions of infections every
year and is notorious for its ability to evade control.
In the United States, the Centers for Disease Control and
Prevention say norovirus causes 21 million illnesses a year,
with 70,000 cases requiring hospitalisation and around 800
ending in death.
Ian Goodfellow, a scientist who has studied norovirus for 10
years, describes it as “the Ferrari of the virus world” and “one
of the most infectious viruses of man”.
Latest HPA data showed a dip in reported norovirus cases
over the Christmas period – something scientists had predicted –
but with 4,140 cases so far in England and Wales, infections are
still 63 percent higher than at this time last year.
For every laboratory-confirmed case, scientists estimate
there are 288 unreported cases, since the vast majority of
people affected don’t go to a doctor. This means the number
affected so far in Britain is more than 1.2 million.
“The emergence of a new strain does not mean that it causes
more serious illness, and managing outbreaks and those with the
illness remains the same,” said David Brown, director of the
virology reference department at the HPA.
“Noroviruses mutate rapidly and new strains are constantly
emerging. At the start of the season it is normal for outbreaks
to be caused by a range of different strains. However, as the
season progresses, particular strains are more successful and
become dominant.”
There is no specific treatment for norovirus infection other
than to let the illness take its course and try to stay hydrated
by drinking regularly. Symptoms usually last around two days.
(Editing by Tom Pfeiffer)
