ABSTRACT
BACKGROUND: Children younger than 36 months with fever without a source (FWS) are at risk of serious bacterial infections (SBI). The risk of occult bacteremia (OB) has been greatly reduced in vaccinated children. The aim of this study is to describe the epidemiology of SBI in children with FWS in our setting and to evaluate the performance of our management algorithm. METHODS: We designed a prospective cohort study. We included children aged 0-36 months presenting with FWS in our emergency unit. Demographic and clinical characteristics, investigations, and management procedures were recorded at the time of inclusion. Information on clinical evolution, final diagnosis, and immunization history were obtained after 10 days. Potential predictors of SBI were compared between patients with and without SBI. RESULTS: Between October 2015 and September 2017, 173 children were recruited, with a median age of 4.4 months (2.1-1). Of these children, 166 (96%) were up to date with their vaccinations. A total of 47 children (27%) had a final diagnosis of SBI, which were all urinary tract infections (UTI). Presence of chills (odds ratio [OR] 5.6, 95% confidence interval [CI] 1.3-24.3), fever for>2 days (OR 29.1, 95% CI 3.5-243.5), and age<9 months (OR: 45.3, 95% CI: 4.9-415.7) were statistically significant predictors of UTI in a multivariate logistic regression. The sensitivity and specificity of our management algorithm were 100% (95% CI: 92.4-100%) and 21.4% (14.6-29.6%), respectively. CONCLUSIONS: In the setting of high vaccination coverage, we only identified SBI related to UTIs. We could not identify any OB. Our management algorithm was able to identify all SBI, but specificity was low. Refined criteria for screening of UTI could slightly increase this.
Subject(s)
Bacterial Infections/complications , Bacterial Infections/diagnosis , Clinical Decision Rules , Fever of Unknown Origin/etiology , Urinary Tract Infections/complications , Urinary Tract Infections/diagnosis , Algorithms , Bacterial Infections/epidemiology , Bacterial Infections/therapy , Case-Control Studies , Child, Preschool , Female , Follow-Up Studies , Humans , Infant , Infant, Newborn , Logistic Models , Male , Prevalence , Prospective Studies , Risk Assessment , Risk Factors , Sensitivity and Specificity , Severity of Illness Index , Switzerland/epidemiology , Treatment Outcome , Urinary Tract Infections/epidemiology , Urinary Tract Infections/therapyABSTRACT
Outbreaks of Streptococcus pyogenes hypervirulent clones are constant public health threats. In western Switzerland, an increase of severe cases of S. pyogenes invasive infections was observed between December 2015 and March 2016. Our aim was (i) to investigate these cases by the use of Whole Genome Sequencing (WGS) and (ii) to determine the specific virulome and resistome of each isolate in order to undertake adequate public health measures. Eleven Streptococcus pyogenes strains isolated from 11 patients with severe invasive infections between December 13, 2015 and March 12, 2016 were included in our study. Practically, emm-typing, MLST and WGS were used to investigate the relatedness between the isolates. The presence of virulence and antibiotic resistance genes as well as mutations in transcriptional regulators of virulence and in genes encoding for antibiotic targets were assessed. Three and two groups of isolates shared the same emm-type and ST type, respectively. Single Nucleotide Polymorphism (SNP) analysis revealed 14 to 32 SNPs between the strains of the same emm-type group, ruling out the possibility of a clonal outbreak. Mutations found in covS and rocA could partially explain an increased virulence. As these reassuring results were obtained in less than 10 days, no specific hospital hygiene and no dedicated public health measures had to be undertaken. WGS is a powerful technique to discriminate between closely related strains, excluding an outbreak in less than 10 days. Moreover, WGS provided extensive data on the virulome and resistome of all these strains.
Subject(s)
Bacteriological Techniques/methods , Disease Outbreaks , Molecular Diagnostic Techniques/methods , Streptococcal Infections/diagnosis , Streptococcal Infections/epidemiology , Streptococcus pyogenes/isolation & purification , Whole Genome Sequencing/methods , Adolescent , Aged , Child , Child, Preschool , Drug Resistance, Bacterial , Female , Genotype , Humans , Infant , Male , Middle Aged , Molecular Typing/methods , Switzerland/epidemiology , Virulence Factors/geneticsABSTRACT
Group B meningococcal infections represent 64% of the invasive meningococcal infections in Switzerland. While conjugate vaccine against group C meningococcus is part of the additional vaccinations of the Swiss vaccinal calendar and quadrivalent vaccines protect against serogroups A, C, Y, and W135, there is presently no available vaccine against group B meningococcus in Switzerland. The use of the capsular polysaccharide from the group B meningococcus is ineffective and possibly dangerous because of its similarity with an adhesion molecule of the human neuronal cells. Development of new vaccines with other antigenic targets gives hope for an optimal protection not only against group B meningococcus, but also against other serogroups that share same antigenic determinants.
