Cases of Tamiflu (or other anti-viral resistance)

niman · **Posted:** Mon Aug 31, 2009 3:09 pm

wotan wrote:

Texas has finally released week 32 surveillance and. as suspected, there are two cases of Tamiflu resistance.

Code:

nfluenza A/H1 (novel)      5      2 (40%)      0 (0)      5      5 (100%)

Looks like the "denied" cases. As originally noted, two cases at the same time in very different locations are cause for concern.

http://www.recombinomics.com/News/08040 ... pread.html

http://www.dshs.state.tx.us/idcu/diseas ... entFlu.pdf

niman · **Posted:** Mon Aug 31, 2009 4:36 pm

Commentary

http://www.recombinomics.com/News/08310 ... irmed.html

Hogweed · **Joined:** Wed Aug 26, 2009 8:08 am **Posts:** 431

niman wrote:

the A193T involved the same position that was linked to the fixing of adamantine resistance, MP S31N, in H3N2. In H3N2, the key change was S193F and position 193 in swine H1N1 is "S". Moreover, the other key H3N2 change was at position 225 (D225N), and D225E has been noted previously in some swine H1N1 isoaltes (including the fit Hong Kong ex-San Francisco isolate).

You make some mention of problems with vaccines associated with these and similar changes in your paper. Also in your commentary http://www.recombinomics.com/News/03240 ... lures.html dating back to March you said

Quote:

Thus, the failure to note the significant H1N1 changes last season and this season, in association with H274Y hitch-hiking, and in the selection of the vaccine target for next season, is cause for concern.

Can you comment on these concerns with relation to the current swine H1N1 vaccine under development?

UBoater · **Joined:** Wed Aug 19, 2009 12:01 pm **Posts:** 265

http://timesofindia.indiatimes.com/NEWS ... 956574.cms

Quote:

AHMEDABAD: Officials of Ahmedabad Municipal Corporation have cast aside fears of H1N1 virus becoming Tamiflu-resistant and will continue
administering the medicine to patients. This after some countries reported mutation of the virus.

"Not a single case in the country has reported mutation so far. Tamiflu treatment has been given to patients which are under category B and C as per guidelines laid down by health ministry," said a senior health official. Till now, city has reported 72 H1N1 positive cases. "On an average, around 8 to 10 contacts of the infected person are regularly monitored and given Tamiflu tablets," added the official.

According to WHO, the worrying development which has been seen in 12 countries, including China and Singapore is of Tamiflu resistant virus. Such cases have also been found in Japan, US, Hong Kong, Denmark and Canada.

niman · **Posted:** Tue Sep 01, 2009 5:48 am

Hogweed wrote:

niman wrote:

the A193T involved the same position that was linked to the fixing of adamantine resistance, MP S31N, in H3N2. In H3N2, the key change was S193F and position 193 in swine H1N1 is "S". Moreover, the other key H3N2 change was at position 225 (D225N), and D225E has been noted previously in some swine H1N1 isoaltes (including the fit Hong Kong ex-San Francisco isolate).

You make some mention of problems with vaccines associated with these and similar changes in your paper. Also in your commentary http://www.recombinomics.com/News/03240 ... lures.html dating back to March you said

Quote:

Thus, the failure to note the significant H1N1 changes last season and this season, in association with H274Y hitch-hiking, and in the selection of the vaccine target for next season, is cause for concern.

Can you comment on these concerns with relation to the current swine H1N1 vaccine under development?

The A193T chnage was also associate with flanking chnages at positions 187, 189, and 196 and some of these associated changes were linked to vaccine resistance. Thus, small chnages in this region can have significant effects on vaccine efficacy,and since such chnages are acquired via recombination, some of the seasonal H1N1 acquisitions could also jump to swine H1N1.

These jumps are the concern. There is a large reservoir in co-circulationg H1N1, also locations, such as Hong Kong are repotrting H3N2 co-circulating with swine H1N1, with little seasonal H1N1 or infleunza B. However, the rapid spread of H1N1 in humans allows for a wide range on co-infections, and jumps back to swine and turkeys increases the number and variety of co-infections.

niman · **Posted:** Tue Sep 01, 2009 5:50 am

niman wrote:

wotan wrote:

Texas has finally released week 32 surveillance and. as suspected, there are two cases of Tamiflu resistance.

Code:

nfluenza A/H1 (novel)      5      2 (40%)      0 (0)      5      5 (100%)

Looks like the "denied" cases. As originally noted, two cases at the same time in very different locations are cause for concern.

http://www.recombinomics.com/News/08040 ... pread.html

http://www.dshs.state.tx.us/idcu/diseas ... entFlu.pdf

Original (Aug 3) description of Tamiflu resistance in Texas

A strain of swine flu that is resistant to treatment with the drug Tamiflu has been discovered near the US-Mexican border, the Pan-American Health Organization (PAHO) said on Monday.

"We have found resistance to Tamiflu on the border. We have observed some cases, few to be sure, in El Paso and close to McAllen, Texas," said Maria Teresa Cerqueira, head of the local PAHO office.

Cases of A(H1N1) that were resistant to the anti-viral medicine have now been found in the United States, Canada, Denmark, Hong Kong and Japan.

Experts gathered in La Jolla, California on Monday to discuss the response to the outbreak, said the resistance was likely due to overuse of antivirals like Tamiflu.

"In the United States Tamiflu is sold with a prescription, but in Mexico and Canada it is sold freely and taken at the first sneeze. Then, when it is really needed, it doesn't work," said Cerqueira.

Roche, the manufacturer of Tamiflu, has said it expects a 0.5 percent rate of case resistance based on clinical trials.

Cerquiera said one patient diagnosed with a Tamiflu-resistant strain had been treated with Zanamivir -- an anti-viral made by GlaxoSmithKline -- and another was given no alternative medication. Both survived.

http://www.google.com/hostednews/afp/ar ... nYOs5DuTtA

niman · **Posted:** Tue Sep 01, 2009 6:54 am

Commentary

http://www.recombinomics.com/News/09010 ... pread.html

gsgs · **Posted:** Thu Sep 03, 2009 4:14 pm

someone asked for it in chat, so here is a paper how/when Amantadine
resistance developed in European swine which then gave M (segment 7) to mexflu

http://vir.sgmjournals.org/cgi/content/full/90/4/900

> As there are no indications that pigs ever have been treated with
> amantadine in Europe, the emergence of amantadine resistance
> has very likely a natural cause.

wotan · **Posted:** Fri Sep 04, 2009 12:17 pm

The week 34 fluview now reports 9 cases of Tamiflu resistance in the US:

Quote:

‡Three state public health laboratories perform antiviral resistance testing and report their results to CDC. An additional two oseltamivir resistant 2009 influenza A (H1N1) viruses have been identified by these laboratories, bringing the total number to nine.

It was in a footnote, and not in the main data table.

It is all H274Y. Sure doesn't sound random or we should see some of the other polymorphisms that convey Tamiflu resistance.

niman · **Posted:** Fri Sep 04, 2009 12:33 pm

wotan wrote:

The week 34 fluview now reports 9 cases of Tamiflu resistance in the US:

Quote:

‡Three state public health laboratories perform antiviral resistance testing and report their results to CDC. An additional two oseltamivir resistant 2009 influenza A (H1N1) viruses have been identified by these laboratories, bringing the total number to nine.

It was in a footnote, and not in the main data table.

It is all H274Y. Sure doesn't sound random or we should see some of the other polymorphisms that convey Tamiflu resistance.

Well, if it is a state performing there own analysis, its not TX. Could be CA. Not sure who the other two states are.

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