title: Clinic- and hospital-based sentinel influenza surveillance, Uganda 2007-2010.
abstract: BACKGROUND
  To assess the epidemiology and seasonality of influenza in Uganda, we established a sentinel surveillance system for influenza in 5 hospitals and 5 outpatient clinics in 4 geographically distinct regions, using standard case definitions for influenzalike illness (ILI) and severe acute respiratory illness (SARI).
  
  
  METHODS
  Nasopharyngeal and oropharyngeal specimens were collected from April 2007 through September 2010 from patients with ILI and SARI aged ≥ 2 months, tested for influenza A and B with real-time reverse-transcription polymerase chain reaction, and subtyped for seasonal A/H1, A/H3, A/H5, and 2009 pandemic influenza A (pH1N1).
  
  
  RESULTS
  Among the 2758 patients sampled, 2656 (96%) enrolled with ILI and 101 (4%) with SARI. Specimens from 359 (13.0%) were positive for influenza; 267 (74.4%) were influenza A, and 92 (25.6%) were influenza B. The median age of both patients with ILI and patients with SARI was 4 years (range, 2 months to 67 years); patients aged 5-14 years had the highest influenza-positive percentage (19.6%), and patients aged 0-4 years had the lowest percentage (9.1%). Influenza circulated throughout the year, but the percentage of influenza-positive specimens peaked during June-November, coinciding with the second rainy season.
  
  
  CONCLUSIONS
  Continued and increased surveillance is needed to better understand the morbidity and mortality of influenza in Uganda.
authors.affiliation: National Influenza Center, Uganda Virus Research Institute, Entebbe,  Uganda.
authors.forename: Julius J
authors.initials: JJ
authors.lastname: Lutwama
authors.forename: Barnabas
authors.initials: B
authors.lastname: Bakamutumaho
authors.forename: John T
authors.initials: JT
authors.lastname: Kayiwa
authors.forename: Richard
authors.initials: R
authors.lastname: Chiiza
authors.forename: Barbara
authors.initials: B
authors.lastname: Namagambo
authors.forename: Mark A
authors.initials: MA
authors.lastname: Katz
authors.forename: Aimee L
authors.initials: AL
authors.lastname: Geissler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000554:Ambulatory Care Facilities; D002648:Child; D002675:Child, Preschool; D005260:Female; D006761:Hospitals; D006801:Humans; D007223:Infant; D009980:Influenza A virus / Q000145:classification / Q000302:isolation & purification*; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000821:virology; D009960:Oropharynx / Q000821:virology; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction; D012621:Seasons; D018571:Sentinel Surveillance; D014454:Uganda / Q000453:epidemiology; D055815:Young Adult