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Treatment and prevention of pandemic H1N1 influenza ('swine influenza')

Anna R Thorner, MD
Section Editor
Martin S Hirsch, MD
Deputy Editor
Elinor L Baron, MD, DTMH


In late March and early April 2009, an outbreak of H1N1 influenza A virus infection was detected in Mexico, with subsequent cases observed in many other countries, including the United States [1,2]. In June 2009, the World Health Organization raised its pandemic alert level to the highest level, phase 6, indicating widespread community transmission on at least two continents [3]. The pandemic was declared to be over in August 2010 [4].

The strategies used for the treatment and prevention of pandemic H1N1 influenza A virus infection will be reviewed here. The epidemiology, transmission, clinical manifestations, and diagnosis of pandemic H1N1 influenza A virus infection are discussed elsewhere. (See "Epidemiology of pandemic H1N1 influenza ('swine influenza')" and "Clinical manifestations and diagnosis of pandemic H1N1 influenza ('swine influenza')".)

The treatment and prevention of seasonal and avian (H5N1) influenza virus infections are also discussed separately. (See "Treatment of seasonal influenza in adults" and "Seasonal influenza in children: Prevention and treatment with antiviral drugs" and "Prevention of seasonal influenza with antiviral drugs in adults" and "Treatment and prevention of avian influenza".)


The following section discusses the agents that were used during the 2009 to 2010 H1N1 influenza A pandemic. Recommendations for the treatment of seasonal influenza are presented separately. (See "Treatment of seasonal influenza in adults" and "Seasonal influenza in children: Prevention and treatment with antiviral drugs", section on 'Antiviral therapy'.)

Antiviral agents

Oseltamivir or zanamivir — During the 2009 to 2010 H1N1 influenza A pandemic, the United States Centers for Disease Control and Prevention (CDC) released guidelines for the use of antivirals for patients with confirmed or suspected influenza virus infection [5]. For most patients with confirmed or suspected influenza infection requiring treatment, a neuraminidase inhibitor (orally inhaled zanamivir or oral oseltamivir) was recommended. These medications are discussed in detail elsewhere. (See "Treatment of seasonal influenza in adults" and "Pharmacology of antiviral drugs for influenza".)


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