Invasive Salmonella Infections at Multiple Surveillance Sites in the Democratic Republic of the Congo, 2011-2014

Clin Infect Dis. 2015 Nov 1;61 Suppl 4:S346-53. doi: 10.1093/cid/civ713.

Abstract

Background: This study reports the microbiological landscape of Salmonella Typhi and invasive nontyphoidal Salmonella (iNTS) in the Democratic Republic of the Congo (DRC).

Methods: Blood cultures obtained from hospital-admitted patients suspected of bloodstream infection (BSI) in 4 of 11 provinces in DRC (Kinshasa, Bas-Congo, Equateur, and Orientale) were processed. Sampling had started in 2007; the results for the period 2011-2014 are reported.

Results: Salmonella Typhi and iNTS were cultured from 194 (1.4%) and 840 (5.9%), respectively, of 14,110 BSI episodes and ranked first among BSI pathogens in adults (65/300 [21.7%]) and children (783/1901 [41.2%]), respectively. A total of 948 of 1034 (91.7%) isolates were available for analysis (164 Salmonella Typhi and 784 iNTS). Salmonella Typhimurium and Salmonella Enteritidis represented 386 (49.2%) and 391 (49.9%), respectively, of iNTS isolates, fluctuating over time and geography and increasing during the rainy season. Adults accounted for <5% of iNTS BSI episodes. Children <5 years accounted for 20.3% of Salmonella Typhi BSI episodes. Among Salmonella Typhi, rates of multidrug resistance and decreased ciprofloxacin susceptibility (DCS) were 37.8% and 37.2%, respectively, and 18.3% displayed combined multidrug resistance and DCS; rates of azithromycin and ceftriaxone resistance were 0.6% and absent, respectively. Among NTS isolates, ≥80% (79.7% of Salmonella Enteritidis and 90.2% of Salmonella Typhimurium isolates) showed multidrug resistance, and <2.5% showed DCS. Combined extended-spectrum β-lactamase production (blaTEM-1 gene) and azithromycin resistance was noted in 12.7% of Salmonella Typhimurium isolates, appearing in Bas-Congo from 2013 onward.

Conclusions: Salmonella Typhi and NTS are major causes of BSI in DRC; their antimicrobial resistance is increasing.

Keywords: Salmonella Typhi; antibiotic resistance; bloodstream infection; nontyphoidal Salmonella.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Bacterial Agents / pharmacology
  • Azithromycin / pharmacology
  • Bacteremia / epidemiology*
  • Bacteremia / microbiology*
  • Child
  • Child, Preschool
  • Ciprofloxacin / pharmacology
  • Democratic Republic of the Congo / epidemiology
  • Drug Resistance, Multiple, Bacterial
  • Epidemiological Monitoring
  • Female
  • Humans
  • Infant
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Salmonella / classification
  • Salmonella / drug effects
  • Salmonella / isolation & purification
  • Salmonella Infections / epidemiology*
  • Salmonella Infections / microbiology*
  • Salmonella enteritidis / drug effects
  • Salmonella enteritidis / isolation & purification
  • Salmonella typhi / drug effects
  • Salmonella typhi / isolation & purification
  • Salmonella typhimurium / drug effects
  • Salmonella typhimurium / isolation & purification
  • Seasons
  • Young Adult
  • beta-Lactamases / metabolism

Substances

  • Anti-Bacterial Agents
  • Ciprofloxacin
  • Azithromycin
  • beta-Lactamases