PLoS ONE (Jan 2017)

Population-based incidence, seasonality and serotype distribution of invasive salmonellosis among children in Nanoro, rural Burkina Faso.

  • Issa Guiraud,
  • Annelies Post,
  • Seydou Nakanabo Diallo,
  • Palpouguini Lompo,
  • Jessica Maltha,
  • Kamala Thriemer,
  • Christian Marc Tahita,
  • Benedikt Ley,
  • Karim Derra,
  • Emmanuel Bottieau,
  • Adama Kazienga,
  • Céline Schurmans,
  • Raffaella Ravinetto,
  • Eli Rouamba,
  • Johan Van Griensven,
  • Sophie Bertrand,
  • Halidou Tinto,
  • Jan Jacobs

DOI
https://doi.org/10.1371/journal.pone.0178577
Journal volume & issue
Vol. 12, no. 7
p. e0178577

Abstract

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Bloodstream infections (BSI) caused by Salmonella Typhi and invasive non-Typhoidal Salmonella (iNTS) frequently affect children living in rural sub-Saharan Africa but data about incidence and serotype distribution are rare.The present study assessed the population-based incidence of Salmonella BSI and severe malaria in a Health and Demographic Surveillance System in a rural area with seasonal malaria transmission in Nanoro, Burkina Faso.Children between 2 months-15 years old with severe febrile illness were enrolled during a one-year surveillance period (May 2013-May 2014). Thick blood films and blood cultures were sampled and processed upon admission. Population-based incidences were corrected for non-referral, health seeking behavior, non-inclusion and blood culture sensitivity. Adjusted incidence rates were expressed per 100,000 person-years of observations (PYO).Among children < 5 years old, incidence rates for iNTS, Salmonella Typhi and severe malaria per 100,000 PYO were 4,138 (95% Confidence Interval (CI): 3,740-4,572), 224 (95% CI: 138-340) and 2,866 (95% CI: 2,538-3,233) respectively. Among those aged 5-15 years, corresponding incidence rates were 25 (95% CI: 8-60), 273 (95% CI: 203-355) and 135 (95% CI: 87-195) respectively. Most iNTS occurred during the peak of the rainy season and in parallel with the increase of Plasmodium falciparum malaria; for Salmonella Typhi no clear seasonal pattern was observed. Salmonella Typhi and iNTS accounted for 13.3% and 55.8% of all 118 BSI episodes; 71.6% of iNTS (48/67) isolates were Salmonella enterica serovar Typhimurium and 25.4% (17/67) Salmonella enterica serovar Enteritidis; there was no apparent geographical clustering.The present findings from rural West-Africa confirm high incidences of Salmonella Typhi and iNTS, the latter with a seasonal and Plasmodium falciparum-related pattern. It urges prioritization of the development and implementation of Salmonella Typhi as well as iNTS vaccines in this setting.