The resurgence of swine-origin influenza A (H1N1)

Unexpectedly, swine-origin influenza A (H1N1) virus (S-OIV, informally known as swine flu) appeared in North America at the very end of the 2008–2009 influenza season and began to spread internationally. As the world mobilizes for a potential pandemic, this article summarizes the developments in diagnosis, treatment, and prevention. Key points What happens in the annual influenza season in the Southern Hemisphere will indicate the prospects of S-OIV progressing to a pandemic. Oseltamivir (Tamiflu) and zanamivir (Relenza) are active against S-OIV and are recommended for hospitalized patients or people at higher risk of influenza-related complications. Otherwise-healthy patients who present with an uncomplicated febrile illness due to S-OIV do not require antiviral treatment. Hand-washing is the most important preventive measure. Vaccine development may take 4 to 6 months. The most difficult question about vaccine development for S-OIV is whether to prepare it as a separate product or incorporate it in the seasonal influenza vaccine.