Amadou Tamsir Diop

Epidemiology and Burden of Bloodstream Infections Caused by Extended-Spectrum Beta-Lactamase Producing Enterobacteriaceae in a Pediatric Hospital in Senegal

Context Severe bacterial infections are not considered as a leading cause of death in young children in sub-Saharan Africa. The worldwide emergence of extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E) could change the paradigm, especially in neonates who are at high risk of developing healthcare-associated infections. Objective To evaluate the epidemiology and the burden of ESBL-E bloodstream infections (BSI). Methods A case-case-control study was conducted in patients admitted in a pediatric hospital during two consecutive years. Cases were patients with Enterobacteriaceae BSI and included ESBL-positive (cases 1) and ESBL-negative BSI (cases 2). Controls were patients with no BSI. Multivariate analysis using a stepwise logistic regression was performed to identify risk factors for ESBL acquisition and for fatal outcomes. A multistate model was used to estimate the excess length of hospital stay (LOS) attributable to ESBL production while accounting for time of infection. Cox proportional hazards models were performed to assess the independent effect of ESBL-positive and negative BSI on LOS. Results The incidence rate of ESBL-E BSI was of 1.52 cases/1000 patient-days (95% CI: 1.2–5.6 cases per 1000 patient-days). Multivariate analysis showed that independent risk factors for ESBL-BSI acquisition were related to underlying comorbidities (sickle cell disease OR = 3.1 (95%CI: 2.3–4.9), malnutrition OR = 2.0 (95%CI: 1.7–2.6)) and invasive procedures (mechanical ventilation OR = 3.5 (95%CI: 2.7–5.3)). Neonates were also identified to be at risk for ESBL-E BSI. Inadequate initial antibiotic therapy was more frequent in ESBL-positive BSI than ESBL-negative BSI (94.2% versus 5.7%, p<0.0001). ESBL-positive BSI was associated with higher case-fatality rate than ESBL-negative BSI (54.8% versus 15.4%, p<0.001). Multistate modelling indicated an excess LOS attributable to ESBL production of 4.3 days. The adjusted end-of-LOS hazard ratio for ESBL-positive BSI was 0.07 (95%CI, 0.04–0.12). Conclusion Control of ESBL-E spread is an emergency in pediatric populations and could be achieved with simple cost-effective measures such as hand hygiene, proper management of excreta and better stewardship of antibiotic use, especially for empirical therapy.

First Description of the Extended Spectrum-Beta-Lactamase Gene blaCTX-M-109 in Salmonella Grumpensis Strains Isolated from Neonatal Nosocomial Infections in Dakar, Senegal

Nosocomial infections are very common in African hospitals, particularly in neonatal units. These infections are most often caused by bacteria such as Escherichia coli, Klebsiella spp and Staphylococcus spp. Salmonella strains are rarely involved in nosocomial infections. Here, we report the first description of S. Grumpensis in neonatal infections in Senegal. Seventeen Salmonella strains were isolated from hospitalized infants’ stool samples. The following resistance phenotype was described in strains: AMXRTICRCFR FOXRCFXRCTXRCAZRIMPSATMRNARNORRCIPRTMRGMRTERSXTR. All isolates were susceptible to imipenem, 15 out of 17 produced an extended spectrum ß-lactamase (ESBL). blaOXA-1, blaSHV-1, blaTEM-1, blaCTX-M1 genes were detected in strains 8, 13, 5 and 8, respectively. blaCTX-M1 sequencing revealed the presence of blaCTX-M-109. Thirteen of the 17 Salmonella Grumpensis strains were analyzed by PFGE. These 13 isolates belonged to a single pulsotype and were genotypically identical. This is the first report of neonatal S. Grumpensis infections in Senegal, and the first report of blaCTX-M-109 in the genus Salmonella.

P087: Multiresistant bacteria bacteremia cases in a Dakar University Hospital (Senegal)

The emergence of multiresistant bacteria strains compromises the efficiency of antibiotics usually used in our structures.

Molecular characterization of group A rotaviruses circulating in Senegal over a 7-year period (2005-2011)

Group A rotaviruses are characterized by large genomic diversity that is typically studied by genotyping of the VP7 glycoprotein, which defines G-type, and the protease-sensitive VP4, which defines P-type. The aim of this study was to examine the genotypes of group A rotavirus strains circulating in Senegal over a 7-year period between 2005 and 2011. ELISA positive stool specimens were analyzed by PAGE and were genotyped by multiplex hemi-nested RT-PCR. Data were analyzed with Epi Info 7 software. Rotavirus was found in 222 samples of stools of which 32 (14.41 %) were positive on PAGE. Five electropherotype patterns were identified, three long (L1, L2 or L3) and two short (S1 or S2). Twenty-three (23) samples had a long electropherotype and nine had a short electropherotype. One hundred strains (45.04%) were analyzed by VP7 genotyping, which identified five different genotypes: G1, G2, G3, G8 and G9. Ninety-three (93) samples (41.89%) were analyzed by VP4 genotyping which showed four different genotypes: P[4], P[6], P[8] and P[11] and mixed genotypes (1.8%). Seventy seven (34.68%) samples were genotyped for both VP7 and VP4. The G1P[8] strain was the most predominant strain followed by the G9P[8] strain. Rotavirus strains circulating in Senegal are genetically diverse. Genotypes G1P[8] and G9P[8] are the predominant strains. We also found mixed infections that could favor the emergence of new viral strains. Thus, regular monitoring of genotypes circulating in the country is required. Key words: Rotavirus, diarrhea, genotypes, children, Senegal.

P020: Multiresistant bacteria in positive urocultures in a Dakar university hospital (Senegal)

Results Three hundred and nine multiresistant bacteria (309) among the 709 mutiresistant strains were isolated from urines (43,58 %). The mean age was 39,73 years [range=1 – 83] with a sex ratio of 0.88. Most of the patients were hospitalized (62,5 %). The infectious diseases clinic provided most of the multiresistant bacteria (41,1 %), followed by the neurology department (14,24 %) and paediatrics department (12,23 %). The majority of multiresistant bacteria were constituted by extended spectrum betalactamase enterobacteriaceae (86, 08 %) and Acinetobacter spp (5, 50 %). E. coli were the most frequent bacteria (35, 92 %) followed by Klebsiella pneumoniae (35, 60). Enterobacteriaceae were susceptible to imipenem, amikacin and colistin but were resistant to quinolones and other aminosides. Methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus saprophyticus were susceptible to vancomycin. Strains of Acinetobacter were susceptible to imipemem and colistin. Conclusion Most of the multiresistant bacteria in the teaching hospital of Fann are isolated from urines. That’s why it is important to insist on prevention by respecting hygiene measures during invasive gestures like pose of urinary catheters.

P243: Evaluation of the management of infectious risk in a neonatal unit in Dakar

A surveillance of multiresistant bacteria was conducted from April to October 2012 in 2 pilot hospitals in Dakar. Results revealed higher infection rates caused by extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL) in neonatal unit associated with an alarming mortality rate.