Influenza A Pandemic (H1N1) 2009 Virus and HIV

To the Editor: The effects of influenza A pandemic (H1N1) 2009 virus infection in HIV-infected patients are unknown. We describe an HIV-infected patient with severe pandemic (H1N1) 2009 virus infection. The patient was a 37-year-old, HIV-positive, former intravenous drug user in a methadone-substitution program. She had a history of smoking, hepatitis C, and mild chronic obstructive pulmonary disease not requiring treatment. Since 2007 her viral load had been 300 cells/μL. Severe pandemic (H1N1) 2009 virus infection most commonly produces fever, dyspnea, respiratory distress, and bilateral patchy pneumonia (3), which can initially be interpreted as bacterial pneumonia and consequently treated with antimicrobial drugs (2–7). We believe that the patient reported here first had a community-acquired pneumonia with a rapid response to treatment and that she secondarily had respiratory distress caused by pandemic (H1N1) 2009 virus pneumonia. We cannot confirm whether the pandemic (H1N1) 2009 virus infection was nosocomial or community acquired. The increased creatine kinase and lactate dehydrogenase and lymphopenia in this patient resemble that reported in Mexico by Perez-Padilla et al. (3). Although these laboratory parameters are unspecific, they could serve as an alert to pneumonia caused by pandemic (H1N1) 2009 virus instead of bacteria. The Centers for Disease Control and Prevention (CDC) recommends testing all HIV-infected patients suspected of having pandemic (H1N1) 2009 virus infection (8). The Spanish Ministry of Health and Madrid Department of Health recommends this testing for patients with an erratic outcome from common pneumonia. For HIV-infected patients who meet case definitions for confirmed, probable, or suspected pandemic (H1N1) 2009 virus infection, CDC recommends empiric antiviral drug treatment (8). There are no known contraindications for co-administration of oseltamivir, a neuraminidase inhibitor, with antiretroviral medications; no interactions have been demonstrated (8,9). Although clinical signs and treatment of pandemic (H1N1) 2009 are similar for patients with and without HIV infection, HIV-infected patients with suspected pandemic (H1N1) 2009 virus symptoms should be treated as soon as possible. CDC recommends the use of influenza antiviral drugs, but this recommendation might change as additional data on this therapy for HIV-infected patients become available. At this time, however, we strongly recommend use of antiviral drugs for HIV-infected patients with suspected pandemic (H1N1) 2009 virus.