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Friday, January 8, 2010

H1N1 Influenza in 2009: From Possibility to Pandemic

Guest blogger Matthew Hoffman, MD, has written for WebMD since 2006. He is a board-certified internist and is currently a fellow in pulmonary and critical care medicine at Emory University, where he also completed medical school and residency.

It’s surprising – and to me a bit exhausting – to realize that H1N1 influenza has been with us for 10 months now. Unlike those daily minor health scares that sometimes seem invented for the 24-hour news cycle, H1N1 influenza has become a persistent serious public health problem. And although we’re seeing a drop in cases of H1N1 flu, there’s still no end in sight.

As we start 2010, let’s catch our breath. Take a look back with me at the time line of H1N1 influenza’s path from discovery to worldwide pandemic in 2009:

March: Doctors take specimen samples from three children in Mexico and southern California with respiratory infections. (All three children recover completely.)

April: Centers for Disease Control and Prevention realize the children were infected with a never-before seen flu virus. The same day, the first recognized death from H1N1 influenza occurs in Mexico.

May: H1N1 flu spreads to every region of the U.S., affecting more than 1,000 people here and 10,000 worldwide. Work on a vaccine begins; the government plans its response.

June: A global pandemic is declared as H1N1 spreads to 74 countries. The World Health Organization (WHO) declares the virus “unstoppable.” The known worldwide death toll reaches 144.

July-August: Clinical trials of an H1N1 vaccine begin in Australia and the U.S. The U.S. Department of Health and Human Services (HHS) allocates $350 million in grants to state and local health agencies. H1N1 cases among students rise as they return to school.

September: The FDA approves four vaccines against H1N1 influenza, and initial clinical trial results show one dose of the vaccine is effective (except in children aged 9 and under, who need two doses).

October: H1N1 explodes in the U.S., spreading from 26 states into 46. The death toll in U.S. children and teens reaches at least 95. HHS releases for distribution 300,000 doses of Tamiflu, an anti-influenza drug. President Obama declares H1N1 a national emergency, allowing states and hospitals to take special measures to prevent and treat H1N1 flu.

November: Confirmed deaths in children and teens with H1N1 influenza reach 198, but CDC estimates the true total to be more than 500. Demand for the vaccine rises – but production problems limit supply, creating widespread shortages.

December: More than 60 million doses of H1N1 vaccine become available, just as H1N1 flu activity begins to decline in many areas of the U.S.

Although H1N1 flu will soon have been with us for a year, it’s still unpredictable. For example, (according to my research) experts still can’t explain why H1N1 influenza persists throughout the seasons, unlike seasonal flu’s predictable cycles. So far, no one is predicting H1N1 flu will be with us permanently, but the CDC is expecting (or at least planning for) further surges in activity in 2010.

So if you haven’t yet, make a resolution to get to your local pharmacy or doctor’s office and get your H1N1 influenza vaccine. There’s plenty to go around now, the vaccine can save your life, and no one knows what’s coming from H1N1 flu in 2010.

SOURCE: “H1N1: Meeting the Challenge.

Posted by: Matthew Hoffman, MD at 6:11 am