New South Wales, Australia: Tamiflu resistant H275Y H1N1 cluster reported

[alert]

http://www.promedmail.org/pls/apex/..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,89966

Archive Number 20110825.2594
Published Date 25-AUG-2011
Subject PRO/EDR> Influenza (50): Australia (NS) H275Y mutation cluster

INFLUENZA (50): AUSTRALIA (NEW SOUTH WALES), H275Y MUTATION CLUSTER
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A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>

Date: Thu 24 Aug 2011
From: Kate Hardie <Kate.Hardie@hnehealth.nsw.gov.au>


A cluster of oseltamivir-resistant A(H1N1)2009 influenza cases with
onset between May and August 2011 has been detected in the Hunter
region of New South Wales (NSW), Australia.

Viruses from 25 of 184 (14 percent) A(H1N1)2009 cases from the Hunter
New England region exhibited highly reduced oseltamivir sensitivity
due to the H275Y substitution in the neuraminidase. The H275Y mutation
is a well-established substitution previously reported to confer
oseltamivir resistance in N1 neuraminidases and was present in the
widespread oseltamivir resistant pre-pandemic seasonal A(H1N1) virus.

15 of the 1st 16 cases lived within a 50-km radius of the regional
centre of Newcastle. 16 of the 25 patients have been interviewed, and
none had received oseltamivir prior to influenza specimen collection.
Only 5 were hospitalised at the time of specimen collection. None of
the 16 had a history of immune suppression; 3 cases were pregnant. No
one was admitted to ICU or had a fatal outcome. Further interviews
with cases and virological analyses are ongoing.

--
Communicated by:
Kate Hardie
Hunter New England Population Health
NSW, Australia
<Kate.Hardie@hnehealth.nsw.gov.au>

Aeron Hurt
WHO Collaborating Centre for Reference and Research on Influenza
Melbourne, Australia

Noelene Wilson
Nicole Gehrig Hunter Area Pathology Service
NSW, Australia

[ProMED-mail thanks Kate Hardie and colleagues for communicating the
discovery of this cluster of oseltamivir-resistance cases in the
Hunter region of New South Wales.

According to the most recent WHO weekly update on oseltamivir
resistance in influenza A(H1N1)2009 viruses, dated 13 Jul 2011, the
cumulative total of cases since April 2009 was 565. It was concluded
that the overall incidence of viruses resistant to antivirals remained
very low, with no recent reports of case clusters. The preceding
report from New South Wales is significant in this respect.

A map of the Hunter Valley region of New South Wales can be accessed
at: <http://www.sydney-australia.biz/maps/hunter-valley-map.php>. -
Mod.CP]

 

[Shiloh]

Re: New South Wales, Australia: Tamiflu resistant H275Y H1N1 cluster reported

Source: http://www.bloomberg.com/news/2011-...ported-in-australia-s-newcastle-who-says.html

Tamiflu-Resistant Flu Outbreak Reported in Australia’s Newcastle, WHO Says
Q
By Jason Gale - Aug 25, 2011 9:25 PM ET

More than two dozen cases of H1N1 swine flu resistant to Roche Holding AG (ROG)’s Tamiflu pill were reported in Australia in the largest outbreak of the drug- evading influenza strain.

Viruses from 25 of 184 patients in the Newcastle area of eastern Australia infected with the pandemic germ had a genetic mutation that reduces the potency of Tamiflu, scientists said in a report distributed today by the International Society for Infectious Diseases’ ProMED-mail program...

 

[Vibrant62]

Re: New South Wales, Australia: Tamiflu resistant H275Y H1N1 cluster reported

From the above report

....Viruses from 25 of 184 (14 percent) A(H1N1)2009 cases from the Hunter
New England region exhibited highly reduced oseltamivir sensitivity
due to the H275Y substitution in the neuraminidase.....

and

...15 of the 1st 16 cases lived within a 50-km radius of the regional
centre of Newcastle. 16 of the 25 patients have been interviewed, and
none had received oseltamivir prior to influenza specimen collection.
Only 5 were hospitalised at the time of specimen collection. None of
the 16 had a history of immune suppression; 3 cases were pregnant. No
one was admitted to ICU or had a fatal outcome. Further interviews
with cases and virological analyses are ongoing.....


One wonders what the outcomes were for the nine cases that were not interviewed?

 

[Emily]

Re: New South Wales, Australia: Tamiflu resistant H275Y H1N1 cluster reported

Does anyone know if the information from the thread below is related to the Tamiflu resistant outbreak strain in New South Wales?

http://www.flutrackers.com/forum/showthread.php?t=169202

 

[tetano]

Re: New South Wales, Australia: Tamiflu resistant H275Y H1N1 cluster reported

Tamiflu-resistant flu outbreak in Newcastle

Over the last few years there has been a lot of international media coverage and government action given to the possibility of a serious influenza pandemic occuring and leading to a large loss of life.

In 2009, an international H1N1 influenza pandemic led to concerns that there would be a repeat of the 1918 influenza pandemic which resulted in many thousands of deaths.

The international reponse in 2009 included travel precautions, governments launched public information campaigns to attempt to restrict the impact of the pandemic and plans were put in place to establish systems of quarantine for infected patients.

The World Health Organisation records over 37,000 cases of the H1N1 pandemic influenza in Australia and 193 confirmed deaths.

An additional concern was the appearance of a strain of H1N1 influenza that was resistant to one of the two most commonly used anti-viral medications, Tamiflu. The mutation of the virus to become resistant to anti-viral medications and also to be easily spread amongst the population was considered to pose a considerable threat.

This week the International Society for Infectious Diseases reported that over two dozen cases of Tamiflu-resistant H1N1 influenza had been reported in Newcastle - the largest outbreak of the drug-resistant strain.

Ian Barr, Deputy Director of the World health Organisation's Collaborating Centre for Influenza in Melbourne said, "As long as it's isolated to Newcastle and that region, it's not so much of a problem. If it spreads further, it might be a concern. Fortunately, we're heading toward the end of our flu season."

Dr Craig Dalton, public health physician from Hunter New England Health and co-ordinator of the Flutracking project said, "It is likely that the strain will spread. The extent to which it replaces the normal H1N1 strain you can only speculate on, in the past it has done this very effectively and we'll wait to see if it happens again. Thankfully there are other anti-viral treatments available that this strain is not resistant to."

The current flu vaccine contains this strain.

"Fortunately for Australia there really are another two or three weeks in which we could get hit by a bad flu as far as an upswing in cases," said Dr Dalton. "The question is, however, whether it then persists through and moves into the northern hemisphere's winter."

http://blogs.abc.net.au/nsw/2011/09/tamiflu-resistant-flu-outbreak-in-newcastle.html