Clinical presentation and prognosis of the 2009 H1N1 influenza A infection in HIV-1-infected patients: a Spanish multicenter study

Abstract
The aim of the study was to describe the clinical presentation and prognosis in HIV-1-infected patients with hospital admission and pandemic influenza A 2009 (H1N1) confirmed, and compare this data with those of a general population. This is a prospective study in nature. All adult patients admitted to 13 hospitals in Spain with confirmed influenza A 2009(H1N1) virus infection by real-time reverse transcriptase PCR assay or culture from June 12 to November 10, 2009 were recruited and followed up until 1 month after discharge. In the HIV group risk factors for HIV infection, AIDS criteria, last CD4 cell count and viral load, and antiretroviral therapy and pneumococcal vaccines were collected. Five hundred and eighty-five patients were recruited, 26 with HIV-1 infection and 559 non-HIV. The HIV patients had a long-term well controlled infection with a median CD4 cell count 503 cells/μl and 84% with undetectable viral load, although more frequently they had chronic liver and chronic obstructive pulmonary disease. No significant differences were observed about reported symptoms and physical findings on hospital admission. About 50% of patients in both groups present radiological infiltrates and 30% present respiratory failures. Practically all the patients in both groups received influenza antiviral therapy and in each group 80% received antibacterial therapy. No differences were observed in clinical outcomes. In HIV patients, well controlled on HAART, the pandemic influenza virus AH1N1 had a similar clinical outcome and prognosis to that of non-HIV patients.