Salmonella Typhi From Blood Cultures in the Democratic Republic of the Congo: A 10-Year Surveillance

Clin Infect Dis. 2019 Mar 7;68(Suppl 2):S130-S137. doi: 10.1093/cid/ciy1116.

Abstract

Background: This study gives an overview of a decade (2007-2017) of hospital-based Salmonella Typhi bloodstream infection (BSI) surveillance in the Democratic Republic of the Congo (DRC), at 4 main sampling sites.

Methods: Blood cultures were sampled in hospital-admitted patients with suspected BSI, according to standardized clinical indications. The results of the surveillance period 2015-2017 were compiled with those of previous surveillance periods (2007-2010 and 2011-2014). Whole genome sequencing of isolates with decreased ciprofloxacin susceptibility (DCS) was performed.

Results: Salmonella Typhi was isolated in 1.4% (531/37 388) and 10.3% (531/5177) of suspected and culture-confirmed BSI episodes, respectively. Salmonella Typhi ranked first among the BSI pathogens in adults (n = 220), but was mostly (n = 301 [56.7%]) isolated from children, of which 72.1% (217/301) and 31.6% (95/301) were <10 years and <5 years old, respectively. Multidrug resistance (MDR), DCS, and combined MDR/DCS were found in 38.3% (n = 180), 24.5% (n = 115), and 11.9% (n = 56) of 470 first isolates, respectively. MDR and DCS rates had increased since 2007, but remained stable during 2015-2017 with no geographical clustering at the province level. Most (91/93 [97.8%]) DCS isolates sequenced belonged to Genotyphi genotype 2.5.1, and gyr S83 was the most frequent DCS mutation (76/93 [81.7%]). Infections occurred perennially, but increased during the rainy season.

Conclusions: Salmonella Typhi was a frequent cause of BSI in adults and children in DRC, with high rates of antibiotic resistance. Sustainable surveillance and implementation of vaccination are compelling.

Keywords: Salmonella Typhi; Democratic Republic of the Congo; surveillance; typhoid fever.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Bacteremia / epidemiology*
  • Bacteremia / microbiology
  • Blood Culture*
  • Child
  • Child, Preschool
  • Democratic Republic of the Congo / epidemiology
  • Drug Resistance, Multiple, Bacterial
  • Epidemiological Monitoring*
  • Genotype
  • Humans
  • Infant
  • Infant, Newborn
  • Microbial Sensitivity Tests
  • Middle Aged
  • Salmonella typhi / drug effects
  • Salmonella typhi / genetics
  • Salmonella typhi / isolation & purification*
  • Seasons
  • Time Factors
  • Typhoid Fever / epidemiology*
  • Young Adult

Substances

  • Anti-Bacterial Agents