Characteristics of Patients With Influenza-Like Illness, Severe Acture Respiratory Illness, and Laboratory-Confirmed Influenza at a Major Children's Hospital in Angola, 2009-2011

Abstract

There are no published data on influenza trends in Angola, where pneumonia is a leading cause of death among young children. This study aims to describe the seasonal trends, types, and subtypes of influenza virus recovered from patients with respiratory illness who were admitted to the major children's hospital in Angola from May 2009 through April 2011. Nasal and oral swabs were collected from patients seen in the outpatient clinic with influenza-like illness (ILI) or hospitalized with severe acute respiratory illness (SARI) and tested for influenza virus by polymerase chain reaction assays. Of 691 samples collected, 334 (48%) were from case patients with ILI, and 357 (52%) were from case patients with SARI. Most (86%) of these children were <5 years of age. Thirty-nine samples (47% SARI, 53% outpatient) tested positive for influenza virus, including 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09; n = 9), influenza A virus subtype H3, likely H3N2 (n = 12), and influenza B virus (n = 18). The proportion of specimens positive for influenza virus was 5% for ILI cases and 6% for SARI cases. After the peak of A(H1N1)pdm09 infection from May through September of 2009, additional peaks of ILI and SARI were seen, especially during February-April 2010. Influenza virus causes a small but preventable number of pneumonia cases among children in Angola.