Anti-viral resistance in 2009 A/H1N1 flu - historical compilation of news

[Rwilmer]

Re: PAHO rejects report of resistant H1N1 cases on US-Mexico border

Re: PAHO rejects report of resistant H1N1 cases on US-Mexico border

Drug resistant swine flu hits Texas; local schools preparing for outbreaks

SAN ANTONIO - One of the best current defenses against the swine flu is showing vulnerability.

MSNBC is reporting that six people have the virus that is resistant to Tamiflu just 220 miles away from San Antonio in McAllen, as well as other border towns like El Paso.

We called local health experts, and they say there is no need to be alarmed. These cases likely popped up because people are overusing the antiviral medication. A resistance can develop when people take it without any symptoms. So don't take it as a precaution. Only take it when it is needed.

When the swine flu outbreak first began in April, we saw a lot of people wearing surgical masks, yet there was no proof the masks offered any protection. But a new study found surgical masks and hand washing decrease your chances of getting the flu.

School districts all across our area are putting together swine flu plans. The best part of any plan is communication. The Center for Disease Control now has a monitoring system where you can report swine flu cases in schools. So if you know about an H1N1-related school or school district dismissal, the CDC would like you to fill out this online report?

http://www.woai.com/content/news/back_to_school/story/Drug-resistant-swine-flu-hits-Texas-local-schools/cFxdOFjZ8E-vMOPDWdI1xQ.cspx

 

[HenryN]

Re: PAHO rejects report of resistant H1N1 cases on US-Mexico border

Re: PAHO rejects report of resistant H1N1 cases on US-Mexico border

Does this imply that CDC does not trust local officials to report 'accurately'?

This means that the CDC has NO real mechanism to monitor schools, which they admitted last year when I asked about school outbreaks during a conference call on Tamiflu resistance.

 

[HenryN]

Re: PAHO rejects report of resistant H1N1 cases on US-Mexico border

Re: PAHO rejects report of resistant H1N1 cases on US-Mexico border

Is that the same number they pulled out when resistant H5N1 1st showed up in Egypt?

.

The number is based on resistance years ago (primarily in H3N2) in children in Japan who were given sub-optimal levels of Tamiflu. The number of recent (since 2006) H3N2 sequences with Tamiflu resistance is ZERO and the vast majority of H1N1 cases with H274Y were NOT treated with Tamiflu.

 

[gsgs]

Re: EM - Tamiflu resistance puzzle

Re: EM - Tamiflu resistance puzzle

my summary: H275Y(6) linked to P453S(1) ?
---------------------------------

can't they show the sequences, so we can decide whether it may
be random ? they may have developed simultaneously.
Strange that revere doesn't even consider this possibility.
They had been advocating free access, free science.

no such link in **, the 3 Danish sequences from today
don't show connections


there are only few oldflu-H1N1 sequences where PB2 and NA are available.
In 2007 we had 308 complete H1N1 genomes, only 29 since then.
Why ? Doesn't this post show, that it's important ? More important now than
it was in 2007

 

[HenryN]

Re: Tamiflu-resistant swine flu found on US-Mexico border

Re: Tamiflu-resistant swine flu found on US-Mexico border

PAHO rejects report of resistant H1N1 cases on US-Mexico border


Cerqueira said she repeated several times that she had no information on any antiviral-resistant cases in the border area. "It is an unfortunate misinterpretation that needs to be clarified," she wrote.

She wrote that she has heard about two antiviral-resistant cases from a physician in Colombia, but that the source did not say they were near the US-Mexico border.


http://www.cidrap.umn.edu/cidrap/content/influenza/swineflu/news/aug0409resistance.html

These comments are still not adding up. There are confirmed H1N1 cases at multiple locations along the Texas / Mexico border, including deaths at multiple locations (see map)

http://flutracker.rhizalabs.com/flu/gmap0908041002.html?lat=27.839076094777816&lon=-105.46875&zoom=6

and cross traffic with Mexico would include Arizona and California, where there are also multiple locations with confirmed cases and deaths on both sides of tborder, so the singling out of two locations in Texas of areas of increased concnern, without reports of Tamiflu resistance, makes little sense. Moreover, the description of the two cases specifically mentions diagnositic resistance, and the presence of H274Y is frequently considered diagnostic for resistance when samples are not formally tested for resistance. At Genbank, sequences with H274Y are labeled with and astrisk with the following warning

* This sequence has the H274Y mutation that might confer resistance to Oseltamivir.

Since it is well known that N1 with H274Y confers resistance in the range of 300-1000 (takes 300 to 1000X the amount of Tamiflu to acheive the same level of inhibition seen in wild type), the presence of H274Y is considered "diagnostic" of resistance (which is confirmed when such samples are directly tested with multiple concentrations of Tamiflu).

Thus, the confusion may simply be PAHO clinging to the absence of formal testing as an excuse for stating there is "no data" on resistance becasue there has been no direct resistance testing (which is only done at a handful of locations world wide - the Tamiflu resistance in Egypt, indicated by another polymorphisms linked to resistance, S294N, was "confirmed" in Atlanta by the CDC, which showed that the S294N confered the same resistance (10-20 fold) previously reported for this genetic change in other isolates.

The subsequent reports of 6 cases of resistance suggest the original remarks of resistance on the Texas / Mexico story were accurate, current "rejection reports" notwithstanding.

 

[GennieF]

Re: PAHO rejects report of resistant H1N1 cases on US-Mexico border

Re: PAHO rejects report of resistant H1N1 cases on US-Mexico border

No Tamiflu Resistant Swine Flu Cases On Mexico/US Border -WHO

ZURICH -(Dow Jones)- The World Health Organization hasn't observed any cases of resistance against the swine flu antiviral drug Tamiflu along the U.S./ Mexican border, WHO spokeswoman Aphaluck Bhatiasevi said Wednesday.

The remarks are in response to a press report quoting WHO Chief Medical Officer Maria Teresa Cerqueira as saying WHO had observed cases of the A/H1N1 swine flu virus along the border between the U.S. and Mexico that have shown a resistance to Roche Holding AG's (ROG.VX) antiviral drug Tamiflu.

"The chief medical officer was misquoted," said Bhatiasevi. "She had said that there are cases of the H1N1/A virus along the border and that the WHO recommends surveying those cases in case a potential resistance occurs. But currently there are no cases of resistance along the border," Bhatiasevi said.

She added that a total of six cases in four countries have shown a resistance to Tamiflu, but that that's a "small number of isolated cases."

The countries are Denmark, Hong Kong, Japan and Canada, according to information on the WHO's web site.

Organization Web site: www.who.int

-By Julia Mengewein, Dow Jones Newswires

http://www.nasdaq.com/aspx/stock-ma...istant-swine-flu-cases-on-mexico/us-borderwho

 

[Commonground]

Tamiflu resistance in pandemic influenza - historical compilation of news

Tamiflu resistance in pandemic influenza - historical compilation of news

Vietnam: Many patients 3 times still testing positive for A/H1N1

Vietnamnet - 36 minutes ago

The treatment of influenza A/H1N1 in Vietnam has recorded the patient's treatment time longer unusual, then many times the test is positive for influenza virus A/H1N1.
Dak Lak province in a patient is admitted and have positive results for influenza A/H1N1 from 24 / 7. Treated properly exposed it after 5 days, the test on 29 / 7, the result is not negative. 2 days later, patients continue to be tested and continue positive.

"This is the first patient to test the 4 th, after almost 10 days with new negative influenza virus A/H1N1," Mr. Tran Quy Tuong, Deputy Director General Management treatment (Ministry of Health ) said.

In Tien Giang, 5 patients with influenza A/H1N1 also fell into a similar situation.

Mr. Trinh Quan Huan, Deputy Minister of Health explained: "Previously, when other types of flu appear (H5N1, H3N2, influenza B), we have used to treat tamiflu. Frequency use tamiflu more likely resistance tamiflu growing. "

Huan He also suggested the primary treatment should reserve Zanamivir filled rooms where a patient's resistance to flu drug Tamiflu. There is still the drug Tamiflu characteristics of the most popular in the treatment of influenza A/H1N1.

According to Nguyen Tran Hien, Director of Institute of hygiene and epidemiology on the central world has 3 vaccine virus A/H1N1 flu tamiflu resistance. "At the vaccine virus A/H1N1 flu in Vietnam is still stable, no changes dị time. The length of treatment such as mentioned above still negative after continued use of tamiflu, " he said Hien.

2 Chinese workers working in Vietnam and infected with influenza A/H1N1
Hoang Dinh Hoan, Director of the Department of Health Lang Son province, said: "today, we discovered there are 2 workers in China to work in projects international venture, construction of good fun , the golf course (under Hoang Dong commune, City Lang Son) are high fever, cough and nearly 38 degrees. "

Department of Health does Lang Son province has sent samples of 2 patients subject workers down about this and epidemiology central to testing.
2 projects where workers are working there are people working. Mr. Hoan said medical center for Lang Son province has khử tr?ng spray the entire project area and isolation of people who have close contact with 2 people this, to prevent disease spread and development of new disease.

On 7 / 8, Vietnam has recorded 35 more cases positive for influenza A/H1N1. In the south: 18 ca, north: of 8, Central 4 ca, Environment: 5 ca.
Thus, up to 17h on 7 / 8, Vietnam has recorded 1,078 cases of positive, 1 deaths.

Number of patients was 628 members. 449 remaining cases are being isolation, treatment at hospitals, treatment facilities, monitoring community health status is stable, without serious complication.

 

[AlaskaDenise]

Re: Tamiflu Resistant Pandemic H1N1 Sequence from Hunan China Released

Re: Tamiflu Resistant Pandemic H1N1 Sequence from Hunan China Released

Commentary

http://www.recombinomics.com/News/08080901/H274Y_WW_Spread.html

Commentary


Global Spread of Tamiflu Resistant Pandemic H1N1
Recombinomics Commentary 20:35
August 8, 2009

The release of a full set of sequences from a patient in Hunan, China raises concerns that oseltamivir resistance is widespread and circulating at much higher frequencies than indicated by the eight detail isolates. The sequence from China, A/Hunan/SWL3/2009, was released yesterday, a day after the CDC released a sequence, A/Singapore/57/2009 at GISAID, which was a day after the sequence from Denmark, A/Denmark/528/2009, was released. All three isolates have H274Y appended onto a different pandemic H1N1 genetic background, and all three backgrounds were distinct from earlier sequences from Osaka, Yamaguchi, and Hong Kong. H274Y was also reported in isolates from patients in Quebec and Tokushima.

This pattern of H274Y on multiple H1N1 backgrounds was also seen in seasonal flu and recently released 2009 seasonal sequences from Central and South American countries also have H274Y, providing a large reservoir of H274Y, which can jump from N1 in seasonal H1N1 to N1 in pandemic H1N1.

Although details of the cases in Hunan and Singapore have not been released, most of the other cases involved patients who were on prophylactic Tamiflu. In Denmark and Tokushima, the patients developed symptoms on the 5th day of prophylactic treatment, raising doubts that the H274Y was due to a de novo mutation. The incubation period for wild type influenza is 2-4 days, so symptoms 5 days after the start of Tamiflu treatment are not likely to be due to de novo mutation, because the incubation period would be significantly longer than wild type, because the newly mutated virus would take longer than five days to grow to a level that would produce symptoms.

In addition, the repeated identification of the same polymorphism, H274Y, and the lack of detection of another resistant polymorphism, N294S, decreases the likelihood that random mutations are generating the resistance.

Instead, it is more likely that H274Y is circulating as a minor population, leading to a shorter incubation period than would be expected for de novo mutation, and a higher frequency of detection. The May 30 isolate date of the Singapore isolate coupled with the release date of August 6, raise concerns that the number of isolates with H274Y that either have not been sequenced or have not had sequences released, may be significant.

The concern was increased by recent reports on multiple resistant isolates along the Texas / Mexican border. Although the claims of confirmed cases were denied, the detail associated with the cases suggests that there is some indication of resistance in this area. Similarly, earlier reports of patients who remained H1N1 positive after extended treatment with Tamiflu raises additional concern of resistant H1N1 that has not been isolated or sequenced.

The rapid spread of H274Y in pandemic H1N1 would not be a surprise. H274Y spread in seasonal flu has been described in detail, and the level rapidly increased to 100%. The co-circulation of H1N1 seasonal flu with H274Y and widespread use of Tamiflu for treatment or prevention, increases the likelihood of rapid spread of H274Y in pandemic H1N1.

The recently released sequences, which contain H274Y on six different genetic backgrounds, including at least one patient who was not treated with Tamiflu, significantly increases concerns of additional worldwide spread in the near term.

.

 

[HenryN]

Re: H1N1 STRAIN RESISTANT TO ANTIVIRALS (Thailand)

Re: H1N1 STRAIN RESISTANT TO ANTIVIRALS (Thailand)

Health experts are urging the public to stay calm after the first case of a Thai H1N1 flu patient developing resistance to the main drug prescribed to treat the virus was found.
The discovery of a H1N1 strain which is resistant to the antiviral drug oseltamivir was made in laboratory tests at Ramathibodi Hospital. http://www.bangkokpost.com/news/local/21721/h1n1-strain-resistant-to-antivirals

The above comments do not address Tamiflu treatment in this patient. Previously all reported resistance cases linked to Tamiflu treatment were in patients receiving a prophylatic does. The dose used to treat this patient is unclear and the report does not state when or if the patient was treated with Tamiflu.

 

[AlaskaDenise]

Re: H1N1 STRAIN RESISTANT TO ANTIVIRALS (Thailand)

Re: H1N1 STRAIN RESISTANT TO ANTIVIRALS (Thailand)

Commentary

http://www.recombinomics.com/News/08090901/H274Y_Thailand.html

Commentary

Tamiflu Resistant Pandemic H1N1 in Thailand
Recombinomics Commentary 00:25
August 9, 2009

Health experts are urging the public to stay calm after the first case of a Thai H1N1 flu patient developing resistance to the main drug prescribed to treat the virus was found.

The discovery of a H1N1 strain which is resistant to the antiviral drug oseltamivir was made in laboratory tests at Ramathibodi Hospital.

The above description describes the first reported case of oseltamivir (Tamiflu) in a pandemic H1N1 patient in Thailand. The report follows the release of a sequence from Hunan, China with H274Y, which followed the release of a sequence from a patient in Singapore, which followed the release of the sequence with H274Y from a patient in Demark. All three sequences were distinct from each other, as well as previous sequences from Japan (Osaka and Yamaguchi) and Hong Kong. Moreover, H274Y has been reported in sequences from patients in Quebec and Tokushima.

The recent release of the sequences signals global spread of resistance, but the report from Thailand creates additional concerns. The number of lab confirmed cases in Thailand should now be above 10,000 and the number of lab confirmed fatalities likely tops 100 (see details in map links). The confirmed cases and deaths have been on a sharp upward slope and the contribution of the resistance to the large number of deaths is unclear.

Similarly, the report does not indicate the treatment status of the patient, who recovered. Previously, most of the described patients were identified while on prophylactic Tamiflu. Thus, development of symptoms while on Tamiflu led to the isolate and sequencing or the reported isolates. However, the resistance in the Thai patient was identified during routine screening raising concerns that the patient was not treated with Tamifu.

The prior isolate from Hong Kong was from a patient traveling from San Francisco who had a mild case and did not receive Tamiflu, before or after she tested positive. Similarly, the sequences from Singapore and Hunan were quietly released at GISAID or Genbank, raising concerns that the resistance was identified during routine sequencing, since the samples were collected in May and mid June, but not reported until this week.

These latest results signal global spread of Tamiflu resistance, which may be associated with evolutionarily fit pandemic H1N1.

Details on the circumstances associated with the resistant patients in Singapore, Hunan, China, and Thailand would be useful.


.

 

[HenryN]

Tamiflu resistance in pandemic influenza - historical compilation of news

Tamiflu resistance in pandemic influenza - historical compilation of news

A 28-year-old American woman who is working here. She returned to Singapore from Honolulu via Tokyo on Tuesday 11.53pm on United Airlines, UA803. She was seated at 33C.

It is likely that the above description is of the first Tamiflu resistance case, represented by isolate A/Singapore/57/2009 which was from a 28F isolated on May 30, 2009.

It is unlikely that this patient was treated with Tamiflu prior to sample collection.

 

[HenryN]

Re: H1N1 STRAIN RESISTANT TO ANTIVIRALS (Thailand)

Re: H1N1 STRAIN RESISTANT TO ANTIVIRALS (Thailand)

Dr. Niman,

I've been reading your commentaries and posts about H1N1 developing Tamiflu resistance in more and more locations around the globe. My question is have you heard anything about H1N1 resistant cases popping up in Vietnam? Has anyone on this site heard of H1N1 resistance showing up in Vietnam? I ask because I saw a news story a few days back about it but I haven't heard anything since. I don't know if these H1N1 resistant cases were officially confirmed by the Vietnamese government. This is the news article published on Thursday July 30th:

Vietnamese H1N1 flu shows sign of resistance to treatments

VietNam News
Publication Date: 30-07-2009

At least four A /H1N1 flu patients had not responded normally to treatment at the HCM City Tropical Diseases Hospital, its deputy director said on Monday.

Two of the cases might be drug resistant, said Dr Tran Tinh Hien.

The announcement by Hien came as the city stepped up preparations to fight the spread of the flu, assigning more facilities and manpower as the number of patients testing positive for the virus increased sharply in recent days.

Health officials have warned that up to 2 million people could be infected by the virus as the epidemic spreads.

Dr Phan Van Nghiem, head of the HCM City Department of Health?s Medical Profession Division, said the municipal administration had allocated VND6 billion for the purchase of facilities like ambulances, respiratory aids and masks for city hospital staff.

All hospitals in the city were now allowed to receive and treat A/H1N1 flu patients and an additional 300 beds hadbeen prepared at district-level hospitals, health officials said during a meeting of health officials and the city?s Committee for Epidemic Prevention on Monday.

Besides the hospital facilities, medicines to treat the flu were also a major issue mentioned by doctors.

With the predicted number of patients, the city needs around 20 million tablets of Tamiflu, while it currently has just 13,000 in stock.

The Ministry of Health would be asked to assist the city in getting more tablets. A city health department official said it had requested the ministry for an immediate addition of 30,000 Tamiflu tablets.

Truong Quoc Cuong, head of the Viet Nam Drug Administration, said the country had enough materials to produce 10 million Tamiflu tablets. If necessary, more medicines as well as materials would be imported, he said.

Meanwhile, director of the Ha Noi Health Department Le Anh Tuan said that the city had prepared an A/H1N1 prevention plan.

Four sub-committees have been formed based on the scenario that health staff, medical facilities and drugs were reserved to provide treatment for 2,000 patients. All hospitals have reserved special isolation and treatment areas and have strengthened communication, and examination and monitoring for the disease.

The municipal health department also requested all State offices and schools to inform the local health sector or to call the department hotline if a case of A/H1N1 occurs. The health sector will send staff to localise and isolate patients, and monitor the disease area.

According to the department?s statistics, as of Tuesday there were 47 A/H1N1 cases in the city. Thirty-one had been discharged from the hospital and 16 were being treated at the National Institute of Infectious and Tropical Diseases.

The Hai Phong Health Department Tuesday also reported the first A/H1N1 flu cluster in the city when five members of one family were found positive with the virus in Kenh Duong Ward, Le Chan District.

The Ministry of Health reported 31 new A/H1N1 cases, bringing the nation?s total to 703 cases and still no fatalities.

http://www.asianewsnet.net/news.php?id=7090&sec=14&t=

bcgauspohl

No, I saw those reports as well as a similar report from India, but have not seen any confirmations (isolation of the H1N1 with H274Y).

 

[AlaskaDenise]

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

Commentary

http://www.recombinomics.com/News/08090903/H274Y_Singapore_Hawaii.html

Commentary

First Tamiflu Resistant Pandemic H1N1 - Singapore ex-Hawaii

Recombinomics Commentary 20:09
August 9, 2009

The third confirmed case is a 28-year-old American female who is working in Singapore. She returned to Singapore from Honolulu via Tokyo on Tuesday, 26 May at 2353 hrs, on United Airlines, UA 803. She was seated at 33C. She became unwell on 26 May.

She returned to Singapore on flight United Airlines 803 from Honolulu via Tokyo on 26 May 2353 hrs. She became unwell while on board and passed through the thermal scanner at the airport as she did not have a fever then. She was referred by her company doctor to TTSH for assessment on 27 May afternoon via a 993 ambulance. Laboratory results confirmed her infection at 1610 hours on 28 May.

For the above cases, they have been discharged from CDC today as they have been cleared of H1N1 virus. They are now on medical leave.

The above descriptions match the patient linked to the recently released NA sequence, A/Singapore/57/2009, by the CDC at GISAID. Although the sequence represents the earliest reported case of H274Y in pandemic H1N1, it was released without fanfare on Thursday. Media reports (see Singapore map) contained the information in the first paragraph above. This information, and the additional information described in Singapore MOH press releases, indicate the case was mild and made no mention of Tamiflu treatment, consistent with the short course and discharge on May 31.

The characterization sheet indicates isolation was on May 30 from a 28 year old female, which is consistent with the above information. The first confirmed case in Singapore was on May 26, and above patient was the third confirmed case. It is the only patient matching age and gender, indicating she is the source of A/Singapore/57/2009. Since she developed symptoms while in flight, the infection was likely from a contact in Honolulu, which is similar to the history of the American traveler from San Francisco. She also had a mild case and refused Tamiflu, but recovered quickly. Although media reports indicated she had a fever when she landed, Hong Kong reports suggested she was asymptomatic at landing, but tested positive shortly thereafter. Thus, infections in both passengers were confirmed in countries in Asia, but infections were in the United States, where there have been no reported cases of Tamiflu resistance.

The export of Tamiflu resistance in the absence of detection in the United States sends a strong signal of a flawed surveillance system. Since both of these cases were mild, yet involved a fit H1N1 with H274Y, the failure to detect similar cases in California or Hawaii may be due to an emphasis on testing more severe cases. The decision to ignore and not report mild cases creates an environment for silent spread of the H1N1 as well as the associated Tamiflu resistance.

Moreover, the release of the sequence in August from a patient infected in April, raises concerns of more such examples in samples collected, but not sequenced, analyzed, or reported. These concerns have been heightened by the frequent detection of H274Y in patients receiving prophylactic Tamiflu, which would be among those most easily identified, as well as additional reports of resistance in China and Thailand, which lack information on the Tamiflu treatment status of the patients or in the case of Thailand, the sample collection date. The sample in China was collected on June 13, again signaling a long delay between sample collection and release of the associated sequences, suggesting that these patients were also not taking Tamiflu, and sequencing of these milder cases has a low priority or a large backlog.

The resistance in patients in Singapore, China, and Thailand released this week adds to concerns associated with the prior Tamiflu resistance cases in Denmark, Japan, Canada and Hong Kong (ex San Francisco), which support silent spread of Tamiflu resistance worldwide.

.

 

[HenryN]

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

Well, it can be a silent spread, or it can be a well monitored noisy spread, but after all is said and done, it will continue to spread nonetheless.

While it will continue to spread, a media myth has been created so MD's believe resistance is rare. As a result, patients in trouble are treated with Tamiflu, leading to more problems. So the key question is whether the media myth on Tamiflu resistance is driving the increasing death toll.

 

[Mamabird]

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

While it will continue to spread, a media myth has been created so MD's believe resistance is rare. As a result, patients in trouble are treated with Tamiflu, leading to more problems. So the key question is whether the media myth on Tamiflu resistance is driving the increasing death toll.

The physicians with which I work have long been concerned with the inappropriate use of Tamiflu, and CDC guidance on the use of antivirals also attempts to keep all on track.

However, it's probably a bit late to attempt to turn things completely around. We will likely continue to see increased resistance, basically in the same manner as Seasonal H1N1. It's just a matter of time.

 

[HenryN]

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

The physicians with which I work have long been concerned with the inappropriate use of Tamiflu, and CDC guidance on the use of antivirals also attempts to keep all on track.

However, it's probably a bit late to attempt to turn things completely around. We will likely continue to see increased resistance, basically in the same manner as Seasonal H1N1. It's just a matter of time.

I agree that the spread will continue, but I think patients are needlessly dying because Tamiflu remains the first treatment choice for SERIOUS cases (which are the patients who are dying or getting hospitaltized).

 

[vinny]

Tamiflu resistance in pandemic influenza - historical compilation of news

Tamiflu resistance in pandemic influenza - historical compilation of news

Flu drugs 'unhelpful' in children

Tamiflu is the antiviral being used in the UK

The antiviral drugs being used to treat swine flu do not appear to work well in children, say UK researchers.

Their work in the British Medical Journal shows Tamiflu and Relenza rarely prevent complications in children who have normal seasonal flu.

Although it is hard to generalise this to the current swine flu pandemic, they say these drugs are unlikely to help children who catch the H1N1 virus.

Side effects and the risk of resistance developing may negate their use.

There were an estimated 30,000 new cases of swine flu in England in the last week, a drop compared with the 110,000 cases the week before.

Our research is finding for most children these antiviral drugs are probably not going to have much of an effect

Study author Dr Matthew Thompson
A decreased incidence has also been seen in Scotland and Wales in the past week.

The total of swine flu-related deaths in England and Scotland stands at 40.

Antivirals are the mainstay of treatment at the moment until a vaccine becomes available, which is expected in September.

The drugs are designed to ensure that symptoms are mild and reduce the chance of an infected person giving the illness to someone else.

The UK has moved beyond the stage of containing swine flu into the "treatment phase", which means that Tamiflu is only being offered to people who have swine flu and not usually to their contacts.

No effect

While the latest study shows that antivirals can shorten the duration of flu in children by up to a day and a half, it also shows that they have little or no effect on asthma flare-ups, ear infections or the likelihood of children needing antibiotics.

The antiviral Tamiflu is also linked to an increased risk of vomiting.

The study also reveals the effectiveness of using antivirals to contain the spread of flu.

They found that 13 people need to be treated to prevent one additional case, meaning antivirals reduce transmission by 8%.

The University of Oxford team, led by Dr Matthew Thompson, carried out a review of four trials on the treatment of seasonal flu in 1,766 children and three trials involving the use of antiviral to limit the spread of seasonal flu in 863 children.

Dr Thompson said: "Our research is finding for most children these antiviral drugs are probably not going to have much of an effect."

Co-researcher Dr Carl Henegan, a GP and expert from the John Radcliffe Hospital in Oxford, said the current policy of giving Tamiflu for mild illness was an "inappropriate strategy".

He said: "The downside of the harms outweigh the one-day reduction in symptomatic benefits."




http://news.bbc.co.uk/1/hi/health/8193012.stm

 

[HenryN]

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

Re: U.S. - First Tamiflu-resistant swine flu (Singapore ex-Hawaii)

I assume you are referring to the fact that by the time they are seriously ill or hospitalized it is too later for Tamiflu to be effective.

No. What I am saying is that physicians assume that resistance may very well happen in the future, but think that currently, there is little, so they treat at risk patients with Tamiflu (patients with underlying conditions that place then at risk for complications). These patients don't respond (or briefly respond) and then become too ill for any antiviral to be effective.

 

[GennieF]

Don't give swine flu drugs to under-12s, says study

Don't give swine flu drugs to under-12s, says study

Don't give swine flu drugs to under-12s, says study

? Side-effects said to outweigh benefits
? Government queries relevance of research

James Sturcke
guardian.co.uk, Monday 10 August 2009 20.33 BST

Children under the age of 12 should not be given Tamiflu or Relenza, the two antiviral drugs that form the cornerstone of the government's fight against swine flu, because their side-effects outweigh any benefits, Oxford University researchers said yesterday.

A study by Dr Matthew Thompson, a clinical scientist, and Dr Carl Heneghan, a clinical lecturer, found that antivirals were no "magic bullet" and only led to a minor reduction in the length of time that a child with mild sickness was ill or the chance of their spreading the disease.

The research, to be published in the British Medical Journal, said that Tamiflu caused vomiting in 5% of children, which could lead to dehydration and complications.

The Oxford researchers, both GPs, said children with mild symptoms should be treated in the same way as if they had any other mild flu ? with drinks to cool high temperatures and rest ? and there was no need for children who were otherwise healthy to be taking Tamiflu or Relenza. They called on the government to be clear about the limitations of the two drugs.

"It would be quite reasonable for the Department of Health to make clear to parents and GPs how much help the drugs are," Thompson told a press conference.

The research, a peer review of seven trials, all but one previously published, looked at the effectiveness of antivirals in reducing seasonal flu complications and stopping the spread of the disease. They said their findings were relevant to the current swine flu outbreak because the diseases shared many characteristics.

They found the drugs had little or no effect on asthma flare-ups, ear infections or the likelihood of a youngster needing antibiotics.

The researchers also found that preventive antiviral use had little effect, reducing transmission of flu by 8%. Thirteen children would have to be treated to prevent one additional case of the flu, they said. The benefit of antivirals was that they reduced symptoms.

Heneghan said the current policy of giving Tamiflu for mild illness was an "inappropriate strategy".

"The downside of the harms outweighs the one-day reduction in symptomatic benefits," Heneghan said.

His advice to GPs was "not to rely on Tamiflu as a treatment to reduce complications" or to think of it as a "magic bullet".

He likened the current policy, which saw more than 315,000 courses of antivirals given out during the first two weeks the national pandemic flu line was in operation, to misguided historical health policies such as the prescription of antibiotics for sore throats.

"The problem is a resistance issue," said Heneghan. "Going forward we have a treatment which is ineffective because we've given it to everybody. We are calling for a more rational prescription process for these drugs."

One of the country's most respected flu experts, Professor Hugh Pennington, agreed that reliance on antivirals was increasing the possibility that the flu would become resistant sooner or later.

"We cannot be certain that the virus will not get nastier. We might require antivirals for the elderly or others who are more likely to get complications. It means the potential that a resistant strain will get that selective advantage as it will grow in a Tamiflu environment."

Norman Lamb, the Liberal Democrat health spokesman, said: "The government antiviral policy and flu line need to be kept under constant review. The cost involved is very high. Perhaps it should come down and be relaunched in the autumn. These are judgments for the chief medical officer."

The Department of Health disputed the relevance of a seasonal flu study to the current outbreak. "The extent to which the findings can be applied to the current pandemic is questionable ? after all, we already know that swine flu behaves differently to seasonal flu, and past pandemics have hit younger people hardest. Whilst there is doubt about how swine flu affects children, we believe a safety-first approach of offering antivirals to everyone remains a sensible and responsible way forward. However, we will keep this policy under review as we learn more about the virus and its effects."

Roche, which makes Tamiflu, said: "Health authorities worldwide such as the National Institute for Health and Clinical Excellence (Nice), European Medicines Agency (EMEA) and the US Food and Drug Administration (FDA) have reviewed the data from controlled clinical trials and approved Tamiflu (oseltamivir) for use in children based upon a positive benefit/risk assessment.

"There are significant data showing the medicine to be effective and well tolerated when used for the treatment or prevention of influenza in children."

http://www.guardian.co.uk/world/2009/aug/10/swine-flu-drugs-under-12s

 

[HenryN]

Re: Mutant strain scare prompts flu drug influx

Re: Mutant strain scare prompts flu drug influx

Source: http://www.bangkokpost.com/news/local/21817/mutant-strain-scare-prompts-flu-drug-influx

The case was proved only by a sequencing test designed to monitor a residue of neuraminidase protein in H1N1 virus sample.

However, it is essential to test the virus resistance on the specific drug to confirm the resistance, he said.

In Thailand, only laboratories at Siriraj Hospital and the Department of Medical Sciences could conduct such a test.

Only Denmark, Hong Kong, Canada and Japan have reported oseltamivir-resistance cases, according to the World Health Organisation.

The above confirms that the resistance is H274Y. It is NOT essential to do a biological test. When H274Y is present in H1N1, it takes 300-1000X as much Tamiflu to match wild type inhibition. H274Y is NOT a borderline resistance situation.

WHO reporting lags. The sequences with H274Y from Singapore (ex Honolulu) and Hunan, China are public (and the Hong Long sequence was from a patient infected in San Francisco).