title: Variations of Invasive Salmonella Infections by Population Size in Asante Akim North Municipal, Ghana.
abstract: BACKGROUND
  The Typhoid Fever Surveillance in Africa Program (TSAP) estimated adjusted incidence rates (IRs) for Salmonella enterica serovar Typhi and invasive nontyphoidal S. enterica serovars (iNTS) of >100 cases per 100 000 person-years of observation (PYO) for children aged <15 years in Asante Akim North Municipal (AAN), Ghana, between March 2010 and May 2012. We analyzed how much these rates differed between rural and urban settings.
  
  
  METHODS
  Children recruited at the Agogo Presbyterian Hospital and meeting TSAP inclusion criteria were included in the analysis. Towns with >32 000 inhabitants were considered urban; towns with populations <5200 were considered rural. Adjusted IRs for Salmonella bloodstream infections were estimated for both settings. Setting-specific age-standardized incidence rates for children aged <15 years were derived and used to calculate age-standardized rate ratios (SRRs) to evaluate differences between settings.
  
  
  RESULTS
  Eighty-eight percent (2651/3000) of recruited patients met inclusion criteria and were analyzed. IRs of Salmonella bloodstream infections in children <15 years old were >100 per 100 000 PYO in both settings. Among rural children, the Salmonella Typhi and iNTS rates were 2 times (SRR, 2.2; 95% confidence interval [CI], 1.3-3.5) and almost 3 times (SRR, 2.8; 95% CI, 1.9-4.3) higher, respectively, than rates in urban children.
  
  
  CONCLUSIONS
  IRs of Salmonella bloodstream infections in children <15 years old in AAN, Ghana, differed by setting, with 2 to nearly 3 times higher rates in the less populated setting. Variations in the distribution of the disease should be considered to implement future studies and intervention strategies.
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Ligia M
authors.initials: LM
authors.lastname: Cruz Espinoza
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Nichols
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, Ghana Institute of Medical Microbiology, University of Cologne.
authors.forename: Yaw
authors.initials: Y
authors.lastname: Adu-Sarkodie
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine German Center for Infection Research, partner site Hamburg-Borstel-Lübeck, Hamburg, Germany.
authors.forename: Hassan M
authors.initials: HM
authors.lastname: Al-Emran
authors.affiliation: Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
authors.forename: Stephen
authors.initials: S
authors.lastname: Baker
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors.forename: John D
authors.initials: JD
authors.lastname: Clemens
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine German Center for Infection Research, partner site Hamburg-Borstel-Lübeck, Hamburg, Germany.
authors.forename: Denise Myriam
authors.initials: DM
authors.lastname: Dekker
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine German Center for Infection Research, partner site Hamburg-Borstel-Lübeck, Hamburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Eibach
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine German Center for Infection Research, partner site Hamburg-Borstel-Lübeck, Hamburg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Krumkamp
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, Ghana.
authors.forename: Kennedy
authors.initials: K
authors.lastname: Boahen
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Justin
authors.initials: J
authors.lastname: Im
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine.
authors.forename: Anna
authors.initials: A
authors.lastname: Jaeger
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Vera
authors.initials: V
authors.lastname: von Kalckreuth
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Gi Deok
authors.initials: GD
authors.lastname: Pak
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Ursula
authors.initials: U
authors.lastname: Panzner
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Se Eun
authors.initials: SE
authors.lastname: Park
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Jin Kyung
authors.initials: JK
authors.lastname: Park
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, Ghana.
authors.forename: Nimako
authors.initials: N
authors.lastname: Sarpong
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea Institute of Medical Microbiology, University of Cologne.
authors.forename: Heidi
authors.initials: H
authors.lastname: Schütt-Gerowitt
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Trevor
authors.initials: T
authors.lastname: Toy
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Wierzba
authors.affiliation: International Vaccine Institute, Seoul, Republic of Korea.
authors.forename: Florian
authors.initials: F
authors.lastname: Marks
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine German Center for Infection Research, partner site Hamburg-Borstel-Lübeck, Hamburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: May
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005869:Ghana / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D062486:Public Health Surveillance; D012111:Residence Characteristics / Q000706:statistics & numerical data; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data*; D012480:Salmonella Infections / Q000453:epidemiology* / Q000382:microbiology; D019779:Salmonella enterica; D014505:Urban Population / Q000706:statistics & numerical data*
keywords: Ghana; Salmonella; rates; rural; urban