title: Sentinel surveillance for influenza among severe acute respiratory infection and acute febrile illness inpatients at three hospitals in Ghana.
abstract: Influenza epidemiology in Africa is generally not well understood. Using syndrome definitions to screen patients for laboratory confirmation of infection is an established means to effectively conduct influenza surveillance.
  
  
  
  To compare influenza-related epidemiologic data, from October 2010 through March 2013, we enrolled hospitalized severe acute respiratory infection (SARI; fever with respiratory symptoms) and acute febrile illness (AFI; fever without respiratory or other localizing symptoms) patients from three referral hospitals in Ghana. Demographic and epidemiologic data were obtained from enrolled patients after which nasopharyngeal and oropharyngeal swabs were collected, and processed by molecular methods for the presence of influenza viruses.
  
  
  
  Of 730 SARI patients, 59 (8%) were influenza positive; of 543 AFI patients, 34 (6%) were positive for influenza. Both SARI and AFI surveillance yielded influenza A(H3N2) (3% versus 1%), A(H1N1)pdm09 (2% versus 1%), and influenza B (3% versus 4%) in similar proportions. Data from both syndromes show year-round influenza transmission but with increased caseloads associated with the rainy seasons.
  
  
  
  As an appreciable percentage of influenza cases (37%) presented without defined respiratory symptoms, and thus met the AFI but not the SARI definition, it is important to consider broader screening criteria (i.e., AFI) to identify all laboratory-confirmed influenza. The identified influenza transmission seasonality has important implications for the timing of related public health interventions.
authors.affiliation: Global Disease Detection and Response Program, U.S. Naval Medical Research Unit No. 3, Cairo, Egypt.
authors.forename: Alexander H
authors.initials: AH
authors.lastname: Jones
authors.affiliation: Noguchi Memorial Institute for Medical Research, National Influenza Center, Accra, Ghana.
authors.forename: William
authors.initials: W
authors.lastname: Ampofo
authors.affiliation: Global Disease Detection and Response Program, U.S. Naval Medical Research Unit No. 3 Ghana Detachment, Accra, Ghana.
authors.forename: Richard
authors.initials: R
authors.lastname: Akuffo
authors.affiliation: Global Disease Detection and Response Program, U.S. Naval Medical Research Unit No. 3 Ghana Detachment, Accra, Ghana.
authors.forename: Brooke
authors.initials: B
authors.lastname: Doman
authors.affiliation: U.S. Naval Medical Research Unit No. 3 Ghana Detachment, Accra, Ghana.
authors.forename: Christopher
authors.initials: C
authors.lastname: Duplessis
authors.affiliation: Ghana Health Service, Accra, Ghana.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Amankwa
authors.affiliation: Ghana Health Service, Accra, Ghana.
authors.forename: Charity
authors.initials: C
authors.lastname: Sarpong
authors.affiliation: Tamale Teaching Hospital, Tamale, Ghana.
authors.forename: Ken
authors.initials: K
authors.lastname: Sagoe
authors.affiliation: 37 Military Hospital, Accra, Ghana.
authors.forename: Prince
authors.initials: P
authors.lastname: Agbenohevi
authors.affiliation: U.S. Naval Medical Research Unit No. 3 Ghana Detachment, Accra, Ghana.
authors.forename: Naiki
authors.initials: N
authors.lastname: Puplampu
authors.affiliation: Noguchi Memorial Institute for Medical Research, Accra, Ghana.
authors.forename: George
authors.initials: G
authors.lastname: Armah
authors.affiliation: Noguchi Memorial Institute for Medical Research, Accra, Ghana.
authors.forename: Kwadwo A
authors.initials: KA
authors.lastname: Koram
authors.affiliation: 37 Military Hospital, Accra, Ghana.
authors.forename: Edward O
authors.initials: EO
authors.lastname: Nyarko
authors.affiliation: 37 Military Hospital, Accra, Ghana.
authors.forename: Samuel
authors.initials: S
authors.lastname: Bel-Nono
authors.affiliation: U.S. Centers for Disease Control & Prevention, Atlanta, GA, USA.|U.S. Naval Medical Research Unit No. 3, Cairo, Egypt.
authors.forename: Erica L
authors.initials: EL
authors.lastname: Dueger
mesh_terms: D000208:Acute Disease / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D005334:Fever; D005869:Ghana / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D053122:Influenza A Virus, H3N2 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology*; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000821:virology; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000821:virology; D018571:Sentinel Surveillance; D055815:Young Adult
keywords: Ghana; human; influenza; sentinel surveillance