tetano
Editor, Senior Moderator
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.
The three patients, after receiving treatment, were in stable condition, he added.
Drug-resistant flu virus strains emerge because of two reasons, the most common being overuse, said Chang Shan-chwen, vice superintendent of the National Taiwan University Hospital.
In the case of oseltamivir, overuse accelerates the evolution of drug resistant characteristics in viruses, Chang said, adding that 40 percent of the some 300 existing drug resistant flu strains had developed in this way.
Viruses also replicate faster and in greater proliferation in weak immune systems, thus increasing the chances of mutation, he said. It is possible that in such a situation, a patient who had not been over-medicated could develop a drug resistant virus, he said.
A total of 363 different H1N1 strains have been detected in Taiwan since last July, but only three are resistant to oseltamivir, said Shih.
"We urge people who contract flu to follow their doctors' advice, " he said. "Over-the-counter drugs are not recommended as over-dosage could lead to a drug resistant phenomenon."
According to the World Health Organization, 383 strains of the H1N1 virus had proved resistant to oseltamivir as of February 23.
In related news, the CDC said Tuesday the flu season had passed its peak transmission period and that the number of people with serious flu symptoms had dropped to 27 from 76 last week.
A recent case study of 100 patients suffering from seasonal flu showed that the average age of those infected was 56, and 85 percent had underlying problems such as diabetes, kidney ailments, and cardiovascular diseases, the CDC said.
http://focustaiwan.tw/ShowNews/WebNews_Detail.aspx?Type=aLIV&ID=201103080022
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.
The three patients, after receiving treatment, were in stable condition, he added.
Drug-resistant flu virus strains emerge because of two reasons, the most common being overuse, said Chang Shan-chwen, vice superintendent of the National Taiwan University Hospital.
In the case of oseltamivir, overuse accelerates the evolution of drug resistant characteristics in viruses, Chang said, adding that 40 percent of the some 300 existing drug resistant flu strains had developed in this way.
Viruses also replicate faster and in greater proliferation in weak immune systems, thus increasing the chances of mutation, he said. It is possible that in such a situation, a patient who had not been over-medicated could develop a drug resistant virus, he said.
A total of 363 different H1N1 strains have been detected in Taiwan since last July, but only three are resistant to oseltamivir, said Shih.
"We urge people who contract flu to follow their doctors' advice, " he said. "Over-the-counter drugs are not recommended as over-dosage could lead to a drug resistant phenomenon."
According to the World Health Organization, 383 strains of the H1N1 virus had proved resistant to oseltamivir as of February 23.
In related news, the CDC said Tuesday the flu season had passed its peak transmission period and that the number of people with serious flu symptoms had dropped to 27 from 76 last week.
A recent case study of 100 patients suffering from seasonal flu showed that the average age of those infected was 56, and 85 percent had underlying problems such as diabetes, kidney ailments, and cardiovascular diseases, the CDC said.
http://focustaiwan.tw/ShowNews/WebNews_Detail.aspx?Type=aLIV&ID=201103080022