title: Acute Febrile Illness and Influenza Disease Burden in a Rural Cohort Dedicated to Malaria in Senegal, 2012-2013.
abstract: BACKGROUND
  African populations are considered to be particularly vulnerable to fever illnesses, including malaria, and acute respiratory disease, owing to limited resources and overcrowding. However, the overall burden of influenza in this context is poorly defined and incidence data for African countries are scarce. We therefore studied the fever syndrome incidence and more specifically influenza incidence in a cohort of inhabitants of Dielmo and Ndiop in Sokone district, Senegal.
  
  
  METHODS
  Daily febrile-illness data were prospectively obtained from January 2012 to December 2013 from the cohort of the villages of Dielmo and Ndiop, initially dedicated to the study of malaria. Nasopharyngeal swabs were collected from, and malaria diagnosis tests (thick blood smears) carried out on, every febrile individual during clinical visits; reverse transcriptase-polymerase chain reaction was used to identify influenza viruses in the samples. Binomial negative regression analysis was used to study the relationship between the monthly incidence rate and various covariates.
  
  
  RESULTS
  In Dielmo and Ndiop, the incidence of malaria has decreased, but fever syndromes remain frequent. Among the 1036 inhabitants included in the cohort, a total of 1,129 episodes of fever were reported. Influenza was present all year round with peaks in October-December 2012 and August 2013. The fever, ILI and influenza incidence density rates differed significantly between age groups. At both sites, the adjusted incidence relative risks for fever syndromes and ILI were significantly higher in the [6-24 months) than other age groups: 7.3 (95%CI: [5.7-9.3]) and 16.1 (95%CI: [11.1-23.3]) respectively. The adjusted incidence relative risk for influenza was significantly higher for the [0-6 months) than other age groups: 9.9 (95%CI: [2.9-33.6]). At both sites, incidence density rates were lowest among adults > = 50 years.
  
  
  CONCLUSIONS
  In this rural setting in Senegal, influenza was most frequent among the youngest children. Preventive strategies targeting this population should be implemented.
authors.affiliation: Epidemiology unit, Pasteur Institute in Dakar, Senegal.
authors.forename: Fatoumata
authors.initials: F
authors.lastname: Diene Sarr
authors.affiliation: Virological unit, Pasteur Institute in Dakar, Senegal.
authors.forename: Mbayame
authors.initials: M
authors.lastname: Niang
authors.affiliation: Epidemiology unit, Pasteur Institute in Dakar, Senegal.
authors.forename: Diamilatou
authors.initials: D
authors.lastname: Thiam
authors.affiliation: Virological unit, Pasteur Institute in Dakar, Senegal.
authors.forename: Ndongo
authors.initials: N
authors.lastname: Dia
authors.affiliation: Epidemiology unit, Pasteur Institute in Dakar, Senegal.
authors.forename: Abdoulaye
authors.initials: A
authors.lastname: Badiane
authors.affiliation: Health district in Sokone, Ministry of Health, Sokone, Senegal.
authors.forename: A B
authors.initials: AB
authors.lastname: Ndao
authors.affiliation: Institut de recherche pour le développement, Dakar, Senegal.
authors.forename: Cheikh
authors.initials: C
authors.lastname: Sokhna
authors.affiliation: Epidemiology unit, Pasteur Institute in Dakar, Senegal.
authors.forename: André
authors.initials: A
authors.lastname: Spiegel
authors.affiliation: Epidemiology unit, Pasteur Institute in Dakar, Senegal.
authors.forename: Vincent
authors.initials: V
authors.lastname: Richard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005334:Fever / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007251:Influenza, Human / Q000150:complications / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D012424:Rural Population; D012675:Senegal / Q000453:epidemiology; D055815:Young Adult