Clinical manifestations of influenza in HIV-infected individuals

Although influenza vaccination is recommended for individuals with HIV infection, there are no data indicating an increased incidence or severity of influenza in this population. We sought to describe the clinical manifestations and morbidity of influenza in HIV-infected patients. All cases of influenza occurring in HIV-infected individuals over 3 years at a large county hospital were reviewed. Forty-three cases of influenza were diagnosed. Most patients presented with typical signs and symptoms of influenza, including cough (90%), myalgias (64%), and fever (52%). Sore throat and headache occurred in less than half of patients. The mean CD4 cell count and HIV viral load in patients with influenza was 340 cells/mm³ and 3.34 log copies/ml, respectively. No significant differences in CD4 counts or viral loads were noted in patients with pneumonia (n=7) compared with patients without pneumonia (n=36), P>0.5. Six patients were hospitalized. One patient each had encephalitis and renal failure, although the relationship to influenza was not clear. No new or unusual clinical manifestations were observed. The rate of pulmonary complications was similar to other studies in HIV-negative patients; however, the hospitalization rate was higher than commonly seen in HIV-negative individuals.