Lower respiratory tract infections associated with influenza A and B viruses in an area with a high prevalence of pediatric human immunodeficiency type 1 infection

Background. Despite the high burden of pediatric HIV-1 infection in developing countries, there are few data on the clinical course of influenza virus-associated lower respiratory tract infection (LRTI) in these children. Objective. To define and compare the clinical course of HIV-1-infected and -uninfected African children hospitalized with influenza virus associated severe LRTI. Methods. Children with severe LRTI were prospectively recruited between March, 1997, and March, 1999, as part of a broader study evaluating the etiology and outcome of this condition in hospitalized HIV-1-infected and -uninfected children. The results of children in whom influenza A or B virus was identified by immunofluorescent antibody staining after shell vial culture are reported. Viruses isolated were typed by hemagglutination inhibition assays. Results. Twenty-five (21.6%) of the 116 children hospitalized with severe LRTI in whom influenza A or B virus was identified were HIV-1-infected. HIV-1-infected children were older than uninfected children (mean age ± sd 17.4 ± 10.8 months vs. 10.2 ± 8.9 months;P = 0.002). HIV-1-infected children were more likely to have an underlying medical illness (in addition to HIV-1 infection) predisposing them to more severe LRTI (32.0%vs. 13.2%;P = 0.03). HIV-infected children were also more likely to have indirect evidence of bacterial coinfection, including chest radiographic evidence of confluent alveolar consolidation (78.9%vs. 35.1%, P = 0.006), and were less likely be wheezing (8.0%vs. 31.9%, P = 0.01). However, there was no difference in the clinical outcome of HIV-1-infected and -uninfected children. The duration of hospitalization [median (range) 5 (2 to 33) days vs. 4 (0 to 21) days, P = 0.08] and the mortality rates (8.0%vs. 2.2%, P = 0.20) were similar between HIV-1-infected and -uninfected children. Conclusion. HIV-1-infected children hospitalized with severe LRTI associated with influenza virus have an outcome similar to that of HIV-1-uninfected children even in the absence of antiretroviral or anti-influenza virus treatment.