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Mexico, D.F. December 13, 2010
While in Mexico, the Ministry of Health has undertaken and intensified vaccination to protect people against influenza, recent studies warn that certain strains of virus with drug resistance develop greater and greater ability to spread.
And U.S. and Canadian researchers confirmed that resistance to two approved classes of antiviral drugs can occur in several ways, and said that this double resistance has been increasing over the past three years.
The team analyzed 28 seasonal influenza virus H1N1 found in five countries from 2008 to 2010, and were resistant to both M2 blockers (enamel) and neuraminidase inhibitors (INA), which include oseltamivir and zanamivir.
The researchers found that antiviral resistance can develop rapidly in a previously virus resistant to one drug through viral mutation, the response to drugs, or genetic exchange with another virus.
The study also found that the proportion of virus evaluated with dual resistance increased from 0.06 percent in 2007 to 2008 to 1.5 percent in 2008 to 2009, and 28 percent in 2009 to 2010.
The findings appear in the online edition of the December 7 issue of the Journal of Infectious Diseases, in advance of print publication in January 1.
"Given that only two classes of antiviral agents are approved, the detection of viruses with resistance to drugs of both classes is worrisome," he said in a news release from the journal study author, Dr. Larisa Gubareva of the Centers for Disease Control and Prevention (CDC) U.S..
"If the movement of such dual-resistant virus is more common among any of the predominant influenza virus circulating, treatment options are extremely limited," he said. "Probably in the future require new antiviral agents and strategies for antiviral therapy."
Another study in the same issue of the magazine considered an outbreak of pandemic influenza H1N1 resistant to oseltamivir in a hematology unit of a British hospital. The researchers concluded that "oseltamivir may not be the first choice drug for patients with hematology and zanamivir may be more beneficial."
In an editorial accompanying both studies, experts said more monitoring, creative prevention and treatment options will be necessary as influenza viruses continue to appear unpredictable and resistant to antiviral drugs.
Just two classes of antiviral drugs approved for use in most countries, and future research should focus on the effectiveness of zanamivir, combination antiretroviral therapy and development of new classes of antiviral drugs, wrote Dr. Frederick G. Hayden, Faculty of Medicine, University of Virginia, and Dr. Menno D. de Jong, University of Amsterdam in the Netherlands. (With information from HealthDay)
Sumed
Mexico, D.F. December 13, 2010
While in Mexico, the Ministry of Health has undertaken and intensified vaccination to protect people against influenza, recent studies warn that certain strains of virus with drug resistance develop greater and greater ability to spread.
And U.S. and Canadian researchers confirmed that resistance to two approved classes of antiviral drugs can occur in several ways, and said that this double resistance has been increasing over the past three years.
The team analyzed 28 seasonal influenza virus H1N1 found in five countries from 2008 to 2010, and were resistant to both M2 blockers (enamel) and neuraminidase inhibitors (INA), which include oseltamivir and zanamivir.
The researchers found that antiviral resistance can develop rapidly in a previously virus resistant to one drug through viral mutation, the response to drugs, or genetic exchange with another virus.
The study also found that the proportion of virus evaluated with dual resistance increased from 0.06 percent in 2007 to 2008 to 1.5 percent in 2008 to 2009, and 28 percent in 2009 to 2010.
The findings appear in the online edition of the December 7 issue of the Journal of Infectious Diseases, in advance of print publication in January 1.
"Given that only two classes of antiviral agents are approved, the detection of viruses with resistance to drugs of both classes is worrisome," he said in a news release from the journal study author, Dr. Larisa Gubareva of the Centers for Disease Control and Prevention (CDC) U.S..
"If the movement of such dual-resistant virus is more common among any of the predominant influenza virus circulating, treatment options are extremely limited," he said. "Probably in the future require new antiviral agents and strategies for antiviral therapy."
Another study in the same issue of the magazine considered an outbreak of pandemic influenza H1N1 resistant to oseltamivir in a hematology unit of a British hospital. The researchers concluded that "oseltamivir may not be the first choice drug for patients with hematology and zanamivir may be more beneficial."
In an editorial accompanying both studies, experts said more monitoring, creative prevention and treatment options will be necessary as influenza viruses continue to appear unpredictable and resistant to antiviral drugs.
Just two classes of antiviral drugs approved for use in most countries, and future research should focus on the effectiveness of zanamivir, combination antiretroviral therapy and development of new classes of antiviral drugs, wrote Dr. Frederick G. Hayden, Faculty of Medicine, University of Virginia, and Dr. Menno D. de Jong, University of Amsterdam in the Netherlands. (With information from HealthDay)