Bird Flu Is Back with an Even Stronger Punch
A few years ago, bird flu was causing a lot of concern as experts worried that the serious influenza would cross over into humans and lead to a widespread outbreak. Now, according to Science Daily News, a virulent new strain of influenza like the one that causes avian flu apparently retains its ability to lead to serious disease in humans even though it has developed a resistance to antiviral medications.
Researchers at the Icahn School of Medicine at Mount Sinai made the discovery and published the results in the science journal, Nature Communications. According to the study, influenza viruses often develop genetic mutations to make them less susceptible to anti-flu drugs. Typically, however, the mutations come at a cost to the virus by weakening its ability to replicate so that it is no longer able to spread from one person to another. According to initial reports, H7N9, an avian strain of influenza A which emerged last spring in China, is capable of quickly developing a mutation to make it resistant to treatment with Tamiflu, an antiviral medication. Patients who developed drug resistance frequently had prolonged, severe infections and poor clinical outcomes.
Differences seen between the current outbreak of H7N9 and other avian influenza strains with the capability of infecting humans includes the rapid development of antiviral resistance in some people treated with Tamiflu and the persistence of high viral loads among those patients. With the combination of flu viruses being able to develop drug-resistance without a tradeoff to their own fitness, and the lack of effective antiviral drugs available to treat them, the study results underscore a need for a bigger arsenal of the drugs and vaccines required to halt the virus. Researchers at Mount Sinai are working towards development of a universal vaccine to prevent multiple strains of influenza.