Anti-viral resistance in 2009 A/H1N1 flu - historical compilation of news
It appears that 19 of the 29 people in this study with oseltamivir resistant A/H1N1pdm09 had no known links to each other. i.e. Possible community spread of oseltamivir resistant A/H1N1pdm09.
Community Transmission of Oseltamivir-Resistant A(H1N1)pdm09 Influenza
N Engl J Med 2011; 365:2541-2542
December 29, 2011
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A fluorescence-based neuraminidase inhibition assay5 of the H275Y isolates showed that the IC50 value (the concentration of drug required to inhibit neuraminidase activity by 50%) was 513 times higher for oseltamivir and 80 times higher for peramivir than the IC50 values associated with wild-type strains.
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Hospital records and interviews with patients and general practitioners revealed that only 1 of the 29 patients with resistant influenza had received oseltamivir before the influenza specimen collection
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Four households had 2 affected patients each, and 2 other patients shared a short car journey. The remaining patients had no known epidemiologic link with the other patients with oseltamivir-resistant influenza described here.
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Re: Anti-viral resistance in 2009 A/H1N1 flu - historical compilation of news
01 June 2011 ‐‐ For this reporting period (18 May ‐ 01 June 2011), 16 new cases of influenza A (H1N1) 2009 viruses carrying the H275Y substitution have been reported. It brings the cumulative total to 508 so far.
Comparison of the WHO updates in May 2010 and June 2011; notice that they changed the a couple of the colors in the chart.
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Re: Anti-viral resistance in 2009 A/H1N1 flu - historical compilation of news
Drug resistant, the H1N1 virus mutated in Singapore and Australia
June 12, 2011 04:04
Singapore - Researchers to the World Health Organization (WHO) states that the H1N1 flu virus that has swept the world in 2009 has been mutated, and now appeared in Singapore and Australia.
New H1N1 virus has a stronger genetic so it is more resistant to drugs such as Tamiflu and Relenza, which is believed to be the mainstay drugs to cope with the H1N1 virus.
Page channelnewsasia.com states, WHO hypothesis was obtained after the researchers found that given the suspect bird flu drug Tamiflu and Relenza was no longer able to cope with the virus attack.
The researchers said the H1N1 virus resistant to Tamiflu, and patients with weak immune eventually died.
But laboratory tests showed the drug was still effective Peravimir flu virus H1N1 overcome.
WHO also reveal new variants in other parts of Asia Pacific. It is feared that if the new form will trigger the spread of swine flu H1N1 virus resistant to the drug would be more serious.
http://www.primaironline.com/berita/...-dan-australia
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Re: Anti-viral resistance in 2009 A/H1N1 flu - historical compilation of news
The Eurosurveillance paper is available at:
Increased detection in Australia and Singapore of a novel influenza A(H1N1)2009 variant with reduced oseltamivir and zanamivir sensitivity due to a S247N neuraminidase mutation
Eurosurveillance website: full free text, http://www.eurosurveillance.org/View...rticleId=19884
Flutrackers.com, abstract: http://www.flutrackers.com/forum/sho...15&postcount=1Leave a comment:
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Re: Anti-viral resistance in 2009 A/H1N1 flu - historical compilation of news
Swine flu starting to show resistance to drugs
10 Jun 2011 10:14
Source: reuters // Reuters
* Reduced sensitivity seen to Roche's Tamiflu, GSK's Relenza
* Affects 30 pct N.Australia samples, 10 pct from Singapore
LONDON, June 10 (Reuters) - A novel variant of swine flu has emerged in Asia with a genetic adaptation giving some resistance to Roche's Tamiflu and GlaxoSmithKline's Relenza, the two mainstay drugs used to tackle the disease.
Researchers said more than 30 percent of H1N1 swine flu infection samples from northern Australia, and more than 10 percent of those in Singapore, collected during the early months of 2011 had mildly reduced sensitivity to the two drugs.
There was no significant reduction in sensitivity to peramivir, an experimental flu drug from BioCryst Pharmaceuticals <BCRX.O>.
...
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Tamiflu resistance in A/H1N1 flu - historical compilation of news
NEWS RELEASE: SIXTH ANTI-VIRAL RESISTANT FLU CASE IDENTIFIED
Delaware?s Division of Public Health (DPH) laboratory results confirm a sixth Delaware case of antiviral-resistant influenza for the 2010 ? 2011 flu season. A 55 year-old woman from Kent County was infected with an influenza strain found to be resistant to oseltamivir, the preferred treatment antiviral medication used to treat confirmed cases of influenza.
There is no reason to change treatment approaches at this time. There are four influenza antiviral medications approved for use in the United States: oseltamivir (brand name Tamiflu), zanamivir (brand name Relenza), amantadine (Symmetrel, generic) and rimantadine (Flumadine, generic).
Although it is late in the flu season, as always DPH recommends the following precautions for both the public and clinicians:
? Get vaccinated against the flu.
? Wash your hands frequently with soap and warm water or use an alcohol-based hand sanitizer.
? Cover your cough/sneeze with a tissue, or cough/sneeze into your inner elbow and not into your hands.
? If you are sick, stay home for at least 24 hours after your fever goes away. This means no fever for at least 24 hours after you have stopped taking any fever-reducing medication. Employers are encouraged to be flexible with their employees on the issue of staying home when ill.
Stay informed about the latest developments on the flu by visiting www.flu.delaware.gov
Delaware Health and Social Services is committed to improving the quality of the lives of Delaware?s citizens by promoting health and well-being, fostering self-sufficiency, and protecting vulnerable populations.
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Re: Tamiflu resistance in A/H1N1 flu - historical compilation of news
Source: http://focustaiwan.tw/ShowNews/WebNe...D=201103080022
Health department reports 3 strains of Tamiflu-resistant H1N1 virus
2011/03/08 19:15:21
Taipei, March 8 (CNA) The Centers for Disease Control (CDC) confirmed Tuesday the discovery of three H1N1 strains that are resistant to the most commonly prescribed antiviral drug Tamiflu.
Three patients infected with the Tamiflu-resistant strains were admitted to hospital in late January and early February this year, said Shih Wen-yi, the CDC's deputy director-general.
However, "there are no signs of these strains spreading into the wider community, " he said, adding that none of the 133 samples taken from people who had contact with the patients had tested positive for resistance to Tamiflu.
The patients, aged 13, 35, and 51, were reported to have low immune systems caused by asthma, a bone marrow transplant, and lupus, respectively, he said.
Tamilfu, which is the generic drug oseltamivir, normally kicks in one to two days after it is started, but in the three cases, they either did not respond or responded poorly, Shih said.
However, the three H1N1 strains, along with another eight that were detected in 2009, can be treated with zanamivir, a prescription drug used mostly against influenza A and B, he said...Leave a comment:
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Tamiflu resistance in A/H1N1 flu - historical compilation of news
The Department of Health's Public Health Laboratory Services Branch (PHLSB) today (March 2) detected the thirteenth case of resistance to oseltamivir (Tamiflu) in a strain of human swine influenza (HSI) virus in Hong Kong.
A department spokesman said the virus was identified during PHLSB's routine sensitivity tests of the HSI virus to oseltamivir and zanamivir.
"Tests showed that this strain is sensitive to zanamivir (Relenza)," he said.
The virus was isolated from the specimen taken from a 58-year-old lady who developed flu-like symptoms since February 6. She was admitted to Prince of Wales Hospital on the same day and her nasopharyngeal specimens taken on February 6, 8 and 9 tested positive for Influenza A virus subtype H1N1 (i.e. Human Swine Influenza) and were sensitive to Tamiflu.
Further test results today showed that the virus isolated from the patient?s nasopharyngeal aspirate on February 11 was resistant to Tamiflu but sensitive to Relenza. She had been prescribed with Tamiflu during hospitalisation and it is likely that Tamiflu resistance emerged during the course of drug treatment.
The patient has been transferred to Shatin Hospital in stable condition.
There was no evidence of further transmission of Tamiflu-resistant HSI from the patient.
The case will be reported to the World Health Organisation.
The spokesman said that Hong Kong has an intensive surveillance system for antiviral resistant influenza viruses. The PHLSB conducts routine sensitivity tests on specimens taken from confirmed HSI patients.
"So far more than 7,000 HSI virus samples have been tested for antiviral sensitivity in Hong Kong," he said.
"We will closely liaise with the WHO and overseas health authorities to monitor the global development of antiviral-resistant HSI virus."
From March 3, cases of tamiflu resistance detected would be reported in the Centre for Health Protection?s weekly report, ?Flu Express? which monitors and summaries the latest local and global influenza activities. The report is available at the Centre?s website (www.chp.gov.hk).
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Tamiflu resistance in A/H1N1 flu - historical compilation of news
Italy, Influenza - Virological Surveillance Update - Week 06/2011 (Ministry of Health, Feb 16 2011, extract, edited): 65.9% of isolates were H1N1 (2009)
[Source: Ministry of Health, full PDF document (in Italian), (LINK). Translated by the Mod.(IOH), edited.]
Italy, Influenza - Virological Surveillance Update - Week 06/2011
16 February 2011
Clinical samples collection activity continues through Influnet laboratories network.
During current week (06/2011), eight hundred and seventy (870) clinical samples have been collected by network's laboratories.
Among these, three hundred forty-nine (349 [40,1%]) were positive for influenza virus.
Ninety-three (93 [26,6%]) were type B, two hundred and thirty (230 [65,9%]) were type A H1N1 (2009), three (3) were A(H3N2) and twenty-three (23) were not yet subtyped.
Table 1 - Virological Surveillance of Influenza - Cumulative Number of Isolates per Week and Type/Subtype (since the start of the season, Week 46/2010
[Type-Subtype / Week (number of isolates): 46 / 47 / 48 / 49 / 50 / 51 / 52 / 01 / 02 / 03 / 04 / 05 / 06, Total]
- INFLUENZA A - 0 - 4 - 3 - 1 - 8 - 20 - 41 - 73 - 177 - 284 - 291 - 240 - 256 - 1.398
- A (not yet subtyped) - ... - 1 - ... - ... - ... - 2 - 2 - 4 - 23 - 32 - 33 - 28 - 23 - 148
- A/H3N2 - ... - ... - ... - 1 - 4 - ... - 3 - 5 - 7 - 2 - 8 - 3 - 33
- A/H1N1 v - ... - 3 - 3 - ... - 4 - 18 - 36 - 69 - 149 - 245 - 256 - 204 - 230 - 1.217
- INFLUENZA B - 0 - 2 - 2 - 1 - 7 - 12 - 17 - 28 - 36 - 58 - 102 - 91 - 93 - 449
- TOTAL POSITIVE SAMPLES - 0 - 6 - 5 - 2 - 15 - 32 - 58 - 101 - 213 - 342 - 393 - 331 - 349 - 1.847
(...)
ANTIVIRAL DRUGS RESISTANCE SURVEILLANCE - ITALY
Since the start of the 2010/2011 influenza season, forty three (43) influenza A(H1N1) 2009 viruses have been tested for antivirals susceptibility; among these, two (2) (4.6%) were resistant to the neuraminidase inhibitor oseltamivir but retained susceptibility to zanamivir.
The two viruses were collected from two hospitalized children in Parma, who were treated with the drug oseltamivir.
Genetic sequence analysis revealed that the two viruses possessed the H274Y substitution on neuraminidase, that confers resistance to oseltamivir.
Drug resistance was confirmed for these viruses through enzyme assays (MUNANA).
In addition, four A(H3N2) and 28 type B viruses have been confirmed susceptible to both oseltamivir and zanamivir.
(...)
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- INFLUENZA A - 0 - 4 - 3 - 1 - 8 - 20 - 41 - 73 - 177 - 284 - 291 - 240 - 256 - 1.398
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Tamiflu resistance in A/H1N1 flu - historical compilation of news
Another case of Tamiflu-resistant human swine influenza detected
Hong Kong (HKSAR) - The Department of Health's Public Health Laboratory Services Branch (PHLSB) today (February 16) detected another case of resistance to oseltamivir (Tamiflu) in a strain of human swine influenza (HSI) virus.
A department spokesman said the virus was identified during PHLSB's routine sensitivity tests of the HSI virus to oseltamivir and zanamivir.
"This is the 10th case of Tamiflu resistance to HSI virus detected in Hong Kong.
more...
Source: HKSAR Government
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Tamiflu resistance in A/H1N1 flu - historical compilation of news
Scand J Infect Dis. 2011 Feb 10. [Epub ahead of print]
Failure of combination oral oseltamivir and inhaled zanamivir antiviral treatment in ventilator- and ECMO-treated critically ill patients with pandemic influenza A (H1N1)v.
Petersen E, Keld DB, Ellermann-Eriksen S, Gubbels S, Ilkj R S, Jensen-Fangel SR, Lindskov C.
Department of Infectious Diseases.
Abstract
Abstract Objective: The objective of this study was to describe the clinical course of severe and complicated pandemic (H1N1)v infection treated with oral oseltamivir and inhaled zanamivir in a series of intensive care patients. Methods: We investigated a case series of patients with respiratory failure and a positive (H1N1)v real-time reverse transcriptase polymerase chain reaction (rRT-PCR). Treatment consisted of oseltamivir tablets 75 mg ? 4 daily in a nasogastric tube plus zanamivir intravenous (i.v.) solution 25 mg ? 4 daily as inhalation. Ventilator inspiratory plateau airway pressure in the ventilator was kept below 30 cmH(2)O, PaO(2) above 8 kPa and pH above 7.30. If this could not be achieved, inhalational nitric oxide (NO) was added or extracorporeal membrane oxygenation (ECMO) was initiated. Results: Twenty-one patients were admitted, with a median age of 50 y (range 6?69 y). Five patients (23.8%) died in the intensive care unit (ICU) and 1 patient died 2 weeks after ICU discharge. Nine patients received ECMO treatment, of whom 3 died during ECMO (33.3%; 3/9) and 1 at 2 weeks after. The mortality in patients not receiving ECMO treatment was 16.6% (2/12). Sixteen patients (76%) were influenza PCR-positive on day 7 after the start of antiviral treatment. Irreversible presumed lung fibrosis complicated with pneumothorax was common. A high Murray score at admission was significantly associated with a fatal outcome. Conclusions: The mortality in these patients was high despite combined antiviral treatment with oseltamivir and zanamivir. Patients shed virus for a long time despite intensive therapy. Optimal management of patients with bilateral pneumonia and respiratory failure caused by (H1N1)v still needs to be determined.
PMID: 21309638 [PubMed - as supplied by publisher]
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Tamiflu resistance in A/H1N1 flu - historical compilation of news
Hong Kong: Tamiflu-resistant human swine influenza virus detected (Feb 11 2011)
[Source: Department of Health, Hong Kong PRC SAR, View Original Article.]
The Department of Health's Public Health Laboratory Services Branch (PHLSB) today (February 11) detected a strain of human swine influenza (HSI) virus which was resistant to oseltamivir (Tamiflu).
A department spokesman said the virus was identified during the PHLSB's routine sensitivity tests of the HSI virus to oseltamivir and zanamivir.
"This is the ninth case of Tamiflu resistance to HSI virus detected in Hong Kong.
"Tests showed that this strain is sensitive to zanamivir (Relenza)," he said.
The virus was isolated from the specimen taken from a seven-year-old girl who had enjoyed good past health. She presented with fever, sore throat, cough and runny nose from January 31. The girl was admitted to Pamela Youde Nethersole Eastern Hospital on February 2. She was discharged the next day in a stable condition.
Her nasopharyngeal aspirate specimen taken on February 2 tested positive for the HSI virus and was resistant to Tamiflu but sensitive to Relenza.
The girl was not prescribed with Tamiflu during hospitalisation.
The spokesman said there was no evidence of further transmission of Tamiflu-resistant HSI from the patient.
The case will be reported to the World Health Organisation (WHO).
The spokesman said that Hong Kong has an intensive surveillance system for antiviral resistant influenza viruses. The PHLSB conducts routine sensitivity tests on specimens taken from confirmed HSI patients.
"So far more than 6,700 HSI virus samples have been tested for antiviral sensitivity in Hong Kong," he said.
"We will closely liaise with the WHO and overseas health authorities to monitor the global development of antiviral-resistant HSI virus."
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Re: Tamiflu resistance in A/H1N1 flu - historical compilation of news
Source:
China
HK detects 9th Tamiflu-resistant A/H1N1 flu virus
English.news.cn 2011-02-11 20:33:06 FeedbackPrintRSS
HONG KONG, Feb. 11 (Xinhua) -- Hong Kong's Department of Health 's Public Health Laboratory Services Branch (PHLSB) announced Friday that it has detected a strain of A/H1N1 flu virus which was resistant to oseltamivir (Tamiflu).
A department spokesman said the virus was identified during the PHLSB's routine sensitivity tests of the A/H1N1 flu virus to oseltamivir and zanamivir.
"This is the ninth case of Tamiflu resistance to A/H1N1 flu virus detected in Hong Kong."...more at the linkLeave a comment:
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Re: Tamiflu resistance in A/H1N1 flu - historical compilation of news
Source:
Hong Kong detects drug-resistant A/H1N1 flu virus
English.news.cn 2011-01-31 19:58:42
HONG KONG, Jan. 31 (Xinhua) -- Hong Kong's Department of Health's Public Health Laboratory Services Branch (PHLSB) Monday announced that a strain of A/H1N1 influenza virus which is resistant to anti-virus drug oseltamivir (Tamiflu) was detected.
A department spokesman Monday said the virus was identified during PHLSB's routine sensitivity tests of the A/H1N1 virus to oseltamivir and zanamivir.
"This is the seventh case of Tamiflu resistance to A/H1N1 flu virus detected in Hong Kong. Tests showed that this strain is sensitive to zanamivir (Relenza)," he said...moreLeave a comment:
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Re: Tamiflu resistance in A/H1N1 flu - historical compilation of news
UK findings hint at spread of resistant H1N1 strain
Robert Roos News Editor
Feb 3, 2011 (CIDRAP News) ? British researchers say 3 of 27 cases of oseltamivir (Tamiflu)-resistant 2009 H1N1 influenza detected in Britain so far this season were in outpatients who had no known exposure to the drug, suggesting that resistant strains may be spreading at a low level in the community.
Writing in Eurosurveillance today, the authors say the finding "suggests possible onward transmission of resistant strains and could be an indication of a possibility of changing epidemiology of oseltamivir-resistant influenza A(H1N1) virus." However, no transmission has been confirmed so far, they report.
Scattered cases of oseltamivir-resistant 2009 H1N1have been detected since early in the 2009 pandemic, most of them in immunosuppressed patients or in hospital patients who had been treated with the drug. A Jan 14 report from the World Health Organization put the global total at 319 cases out of 20,000 samples tested, the British researchers note....more at the link.Leave a comment:
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