title: Incidence of invasive salmonella disease in sub-Saharan Africa: a multicentre population-based surveillance study.
abstract: Available incidence data for invasive salmonella disease in sub-Saharan Africa are scarce. Standardised, multicountry data are required to better understand the nature and burden of disease in Africa. We aimed to measure the adjusted incidence estimates of typhoid fever and invasive non-typhoidal salmonella (iNTS) disease in sub-Saharan Africa, and the antimicrobial susceptibility profiles of the causative agents.
  
  
  
  We established a systematic, standardised surveillance of blood culture-based febrile illness in 13 African sentinel sites with previous reports of typhoid fever: Burkina Faso (two sites), Ethiopia, Ghana, Guinea-Bissau, Kenya, Madagascar (two sites), Senegal, South Africa, Sudan, and Tanzania (two sites). We used census data and health-care records to define study catchment areas and populations. Eligible participants were either inpatients or outpatients who resided within the catchment area and presented with tympanic (≥38·0°C) or axillary temperature (≥37·5°C). Inpatients with a reported history of fever for 72 h or longer were excluded. We also implemented a health-care utilisation survey in a sample of households randomly selected from each study area to investigate health-seeking behaviour in cases of self-reported fever lasting less than 3 days. Typhoid fever and iNTS disease incidences were corrected for health-care-seeking behaviour and recruitment.
  
  
  
  Between March 1, 2010, and Jan 31, 2014, 135 Salmonella enterica serotype Typhi (S Typhi) and 94 iNTS isolates were cultured from the blood of 13 431 febrile patients. Salmonella spp accounted for 33% or more of all bacterial pathogens at nine sites. The adjusted incidence rate (AIR) of S Typhi per 100 000 person-years of observation ranged from 0 (95% CI 0-0) in Sudan to 383 (274-535) at one site in Burkina Faso; the AIR of iNTS ranged from 0 in Sudan, Ethiopia, Madagascar (Isotry site), and South Africa to 237 (178-316) at the second site in Burkina Faso. The AIR of iNTS and typhoid fever in individuals younger than 15 years old was typically higher than in those aged 15 years or older. Multidrug-resistant S Typhi was isolated in Ghana, Kenya, and Tanzania (both sites combined), and multidrug-resistant iNTS was isolated in Burkina Faso (both sites combined), Ghana, Kenya, and Guinea-Bissau.
  
  
  
  Typhoid fever and iNTS disease are major causes of invasive bacterial febrile illness in the sampled locations, most commonly affecting children in both low and high population density settings. The development of iNTS vaccines and the introduction of S Typhi conjugate vaccines should be considered for high-incidence settings, such as those identified in this study.
  
  
  
  Bill & Melinda Gates Foundation.
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea. Electronic address: fmarks@ivi.int.
authors.forename: Florian
authors.initials: F
authors.lastname: Marks
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Vera
authors.initials: V
authors.lastname: von Kalckreuth
authors.affiliation: Bandim Health Project, Bissau, Guinea-Bissau; Research Center for Vitamins and Vaccines, Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Aaby
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Yaw
authors.initials: Y
authors.lastname: Adu-Sarkodie
authors.affiliation: Faculty of Medicine, University of Gezira, Wad Medani, Sudan.
authors.forename: Muna Ahmed
authors.initials: MA
authors.lastname: El Tayeb
authors.affiliation: Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ali
authors.affiliation: Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
authors.forename: Abraham
authors.initials: A
authors.lastname: Aseffa
authors.affiliation: Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
authors.forename: Stephen
authors.initials: S
authors.lastname: Baker
authors.affiliation: Kilimanjaro Christian Medical Centre, Moshi, Tanzania; Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC, USA.
authors.forename: Holly M
authors.initials: HM
authors.lastname: Biggs
authors.affiliation: Bandim Health Project, Bissau, Guinea-Bissau; Research Center for Vitamins and Vaccines, Copenhagen, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Bjerregaard-Andersen
authors.affiliation: Centers for Disease Control and Prevention, Nairobi, Kenya; Global Health Institute, Emory University, Atlanta, GA, USA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Breiman
authors.affiliation: Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
authors.forename: James I
authors.initials: JI
authors.lastname: Campbell
authors.affiliation: Centers for Disease Control and Prevention, Nairobi, Kenya; WHO-Kenya Country Office, Nairobi, Kenya.
authors.forename: Leonard
authors.initials: L
authors.lastname: Cosmas
authors.affiliation: Kilimanjaro Christian Medical Centre, Moshi, Tanzania; Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC, USA; Duke Global Health Institute, Duke University, Durham, NC, USA; Centre for International Health, University of Otago, Dunedin, New Zealand.
authors.forename: John A
authors.initials: JA
authors.lastname: Crump
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Ligia Maria Cruz
authors.initials: LMC
authors.lastname: Espinoza
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Jessica Fung
authors.initials: JF
authors.lastname: Deerin
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; German Center for Infection Research, Hamburg-Borstel-Lübeck, Germany.
authors.forename: Denise Myriam
authors.initials: DM
authors.lastname: Dekker
authors.affiliation: Centers for Disease Control and Prevention, Nairobi, Kenya.
authors.forename: Barry S
authors.initials: BS
authors.lastname: Fields
authors.affiliation: Faculty of Medicine, University of Gezira, Wad Medani, Sudan; Faculty of Science, University of Hafr Al Batin, Hafr Al Batin, Saudi Arabia.
authors.forename: Nagla
authors.initials: N
authors.lastname: Gasmelseed
authors.affiliation: Kilimanjaro Christian Medical Centre, Moshi, Tanzania; Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC, USA.
authors.forename: Julian T
authors.initials: JT
authors.lastname: Hertz
authors.affiliation: Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
authors.forename: Nguyen
authors.initials: N
authors.lastname: Van Minh Hoang
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Justin
authors.initials: J
authors.lastname: Im
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Jaeger
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Hyon Jin
authors.initials: HJ
authors.lastname: Jeon
authors.affiliation: Schiphra Hospital, Ouagadougou, Burkina Faso.
authors.forename: Leon Parfait
authors.initials: LP
authors.lastname: Kabore
authors.affiliation: National Institute for Communicable Diseases, Johannesburg, South Africa; Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Karen H
authors.initials: KH
authors.lastname: Keddy
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Frank
authors.initials: F
authors.lastname: Konings
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; German Center for Infection Research, Hamburg-Borstel-Lübeck, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Krumkamp
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea; Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Australia.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Ley
authors.affiliation: Bandim Health Project, Bissau, Guinea-Bissau; Research Center for Vitamins and Vaccines, Copenhagen, Denmark.
authors.forename: Sandra Valborg
authors.initials: SV
authors.lastname: Løfberg
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; German Center for Infection Research, Hamburg-Borstel-Lübeck, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: May
authors.affiliation: Institute of Tropical Medicine, Eberhard-Karls University Tübingen, Tübingen, Germany; Duy Tan University, Da Nang, Vietnam.
authors.forename: Christian G
authors.initials: CG
authors.lastname: Meyer
authors.affiliation: National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Mintz
authors.affiliation: Centers for Disease Control and Prevention, Nairobi, Kenya.
authors.forename: Joel M
authors.initials: JM
authors.lastname: Montgomery
authors.affiliation: Institute Pasteur de Dakar, Dakar, Senegal.
authors.forename: Aissatou Ahmet
authors.initials: AA
authors.lastname: Niang
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Nichols
authors.affiliation: Center for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Olack
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Gi Deok
authors.initials: GD
authors.lastname: Pak
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Ursula
authors.initials: U
authors.lastname: Panzner
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Jin Kyung
authors.initials: JK
authors.lastname: Park
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Se Eun
authors.initials: SE
authors.lastname: Park
authors.affiliation: Laboratory of Microbiology, University of Antananarivo, Antananarivo, Madagascar.
authors.forename: Henintsoa
authors.initials: H
authors.lastname: Rabezanahary
authors.affiliation: Laboratory of Microbiology, University of Antananarivo, Antananarivo, Madagascar.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Rakotozandrindrainy
authors.affiliation: Laboratory of Microbiology, University of Antananarivo, Antananarivo, Madagascar.
authors.forename: Tiana Mirana
authors.initials: TM
authors.lastname: Raminosoa
authors.affiliation: Laboratory of Microbiology, University of Antananarivo, Antananarivo, Madagascar.
authors.forename: Tsiriniaina Jean Luco
authors.initials: TJL
authors.lastname: Razafindrabe
authors.affiliation: Schiphra Hospital, Ouagadougou, Burkina Faso.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Sampo
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea; Institute of Medical Microbiology, University of Cologne, Cologne, Germany.
authors.forename: Heidi
authors.initials: H
authors.lastname: Schütt-Gerowitt
authors.affiliation: Institute Pasteur de Dakar, Dakar, Senegal; University Cheikh Anta Diop de Dakar, Dakar, Senegal.
authors.forename: Amy Gassama
authors.initials: AG
authors.lastname: Sow
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; German Center for Infection Research, Hamburg-Borstel-Lübeck, Germany.
authors.forename: Nimako
authors.initials: N
authors.lastname: Sarpong
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Seo
authors.affiliation: National Institute for Communicable Diseases, Johannesburg, South Africa.
authors.forename: Arvinda
authors.initials: A
authors.lastname: Sooka
authors.affiliation: Institut Supérieur des Sciences de la Population, University of Ouagadougou, Ouagadougou, Burkina Faso.
authors.forename: Abdramane Bassiahi
authors.initials: AB
authors.lastname: Soura
authors.affiliation: Institute Pasteur de Dakar, Dakar, Senegal.
authors.forename: Adama
authors.initials: A
authors.lastname: Tall
authors.affiliation: Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
authors.forename: Mekonnen
authors.initials: M
authors.lastname: Teferi
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea; Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Australia.
authors.forename: Kamala
authors.initials: K
authors.lastname: Thriemer
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Warren
authors.affiliation: Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
authors.forename: Biruk
authors.initials: B
authors.lastname: Yeshitela
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea; International Centre for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh; University of California Fielding School of Public Health, Los Angeles, CA, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Clemens
authors.affiliation: International Vaccine Institute, SNU Research Park, Seoul, South Korea.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Wierzba
mesh_terms: D000293:Adolescent; D017954:Africa South of the Sahara / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D018432:Drug Resistance, Multiple; D005191:Family Characteristics; D005260:Female; D005334:Fever / Q000209:etiology / Q000382:microbiology; D006801:Humans; D015994:Incidence; D008297:Male; D012475:Salmonella / Q000302:isolation & purification; D012480:Salmonella Infections / Q000453:epidemiology* / Q000382:microbiology; D014435:Typhoid Fever / Q000453:epidemiology* / Q000382:microbiology