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

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.

High genetic similarity between non-typhoidal Salmonella isolated from paired blood and stool samples of children in the Democratic Republic of the Congo

“…Lastly, the date of onset of symptoms was not registered, nor was the occurrence of gastrointestinal symptoms. As to its strengths, blood cultures were systematically sampled based on harmonized indications and the hospital staff got the trust of the patient's families facilitating enrollment [ 14 , 15 ].…”

“…The study took place from November 2013 to April 2017 at the hospital of Saint-Luc in Kisantu (HSLK), Kongo-Central province, Democratic Republic of the Congo (DR Congo). HSLK is the major sampling site of the microbiological surveillance network organized by the Institut National de Recherche Biomédicale (INRB), Kinshasa, DR Congo, and the Institute of Tropical Medicine, Antwerp, Belgium [4,14]. Over a 10-year period (2007-2017), NTS ranked first as a cause of BSI in children accounting for 63.8% of culture-confirmed BSI [14,15].…”

“…cultures were systematically sampled based on harmonized indications and the hospital staff got the trust of the patient's families facilitating enrollment [14,15].…”

Diagnostic Bacteriology in District Hospitals in Sub-Saharan Africa: At the Forefront of the Containment of Antimicrobial Resistance

“…Indeed, this spectrum can vary considerably in different sites and settings. Surveillance can therefore determine the occurrence and proportions of geographically confined pathogens such as Burkholderia pseudomallei (melioidosis, South-East Asia) (53), Streptococcus suis (zoonotic meningitis and sepsis, Asia) (55) and Salmonella species (both typhoidal and non-typhoidal) (54, 63, 64). Consistent blood culture surveillance as part of capacity building projects also allows for early alerts for hospital and community outbreaks (Box 3).…”

Antimicrobial resistance among pathogens that infect the bloodstream: a multicenter surveillance report for 1998–2017

“…The most common Gram-positive bacteria were coagulase-negative Staphylococcus (CNS) and Staphylococcus aureus (Fig 2) Our study showed that S. typhi was also a main BSI-associated pathogen in Hubei Province from 1998-2003. Typhoid fever is a poverty-related disease, mainly occurring in Africa and Asia, with a low incidence in economically developed regions such as Europe and the United States [11][12][13][14][15]. Typhoid fever is transmitted mainly through contaminated food and drinking water [16].…”