RESUMEN
Legionella is the causative agent for Legionnaires' disease (LD) and is responsible for several large outbreaks in the world. More than 90% of LD cases are caused by Legionella pneumophila, and studies on the origin and transmission routes of this pathogen rely on adequate molecular characterization of isolates. Current typing of L. pneumophila mainly depends on sequence-based typing (SBT). However, studies have shown that in some outbreak situations, SBT does not have sufficient discriminatory power to distinguish between related and nonrelated L. pneumophila isolates. In this study, we used a novel high-resolution typing technique, called whole-genome mapping (WGM), to differentiate between epidemiologically related and nonrelated L. pneumophila isolates. Assessment of the method by various validation experiments showed highly reproducible results, and WGM was able to confirm two well-documented Dutch L. pneumophila outbreaks. Comparison of whole-genome maps of the two outbreaks together with WGMs of epidemiologically nonrelated L. pneumophila isolates showed major differences between the maps, and WGM yielded a higher discriminatory power than SBT. In conclusion, WGM can be a valuable alternative to perform outbreak investigations of L. pneumophila in real time since the turnaround time from culture to comparison of the L. pneumophila maps is less than 24 h.
Asunto(s)
Mapeo Cromosómico/métodos , Legionella pneumophila/clasificación , Legionella pneumophila/genética , Enfermedad de los Legionarios/microbiología , Tipificación Molecular/métodos , Brotes de Enfermedades , Genotipo , Humanos , Enfermedad de los Legionarios/epidemiología , Epidemiología Molecular/métodos , Países Bajos/epidemiología , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
BACKGROUND: This study evaluated the effects of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV) on nasopharyngeal bacterial colonization compared with the 7-valent pneumococcal conjugate vaccine (7vCRM) in young children. METHODS: A randomized controlled trial in the Netherlands, initiated 2 years after 7vCRM introduction, was conducted between 1 April 2008 and 1 December 2010. Infants (N = 780) received either PHiD-CV or 7vCRM (2:1) at 2, 3, 4, and 11-13 months of age. Nasopharyngeal samples taken at 5, 11, 14, 18, and 24 months of age were cultured to detect Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Staphylococcus aureus. Polymerase chain reaction assays quantified H. influenzae and S. pneumoniae and confirmed H. influenzae as nontypeable (NTHi). Primary outcome measure was vaccine efficacy (VE) against NTHi colonization. RESULTS: In both groups, NTHi colonization increased with age from 33% in 5-month-olds to 65% in 24-month-olds. Three months postbooster, VE against colonization was 0.5% (95% confidence interval [CI], -21.8% to 18.4%) and VE against acquisition 10.9% (95% CI, -31.3% to 38.9%). At each sampling moment, no differences between groups in either NTHi prevalence or H. influenzae density were detected. Streptococcus pneumoniae (range, 39%-57%), M. catarrhalis (range, 63%--69%), and S. aureus (range, 9%-30%) colonization patterns were similar between groups. CONCLUSIONS: PHiD-CV had no differential effect on nasopharyngeal NTHi colonization or H. influenzae density in healthy Dutch children up to 2 years of age, implying that herd effects for NTHi are not to be expected. Other bacterial colonization patterns were also similar.
Asunto(s)
Infecciones por Haemophilus/prevención & control , Haemophilus influenzae/aislamiento & purificación , Nasofaringe/microbiología , Vacunas Neumococicas/administración & dosificación , Factores de Edad , Técnicas de Tipificación Bacteriana , Preescolar , Femenino , Haemophilus influenzae/clasificación , Interacciones Huésped-Patógeno , Humanos , Esquemas de Inmunización , Lactante , Masculino , Infecciones Neumocócicas/prevención & control , Streptococcus pneumoniae/aislamiento & purificaciónRESUMEN
In a prospective study involving 642 patients with febrile urinary tract infection (UTI), we found antimicrobial pretreatment (odds ratio [OR], 3.3), an indwelling urinary catheter (OR, 2.8), and malignancy (OR, 2.7) to be independent risk factors for bacteremia with a uropathogen that was not cultured or recognized in the urine. Although the diagnostic value of blood cultures has been questioned in UTI, we advocate performing blood cultures for patients with these risk factors.
Asunto(s)
Bacteriemia/epidemiología , Infecciones Urinarias/complicaciones , Orina/microbiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Catéteres de Permanencia/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/complicaciones , Estudios Prospectivos , Factores de Riesgo , Infecciones Urinarias/microbiología , Adulto JovenAsunto(s)
Antibacterianos/farmacología , Ciprofloxacina/farmacología , Farmacorresistencia Bacteriana , Legionella pneumophila/efectos de los fármacos , Enfermedad de los Legionarios/microbiología , Neumonía/microbiología , Proteínas Bacterianas/genética , Girasa de ADN/genética , Farmacorresistencia Bacteriana/genética , Humanos , Legionella pneumophila/genética , Legionella pneumophila/aislamiento & purificación , Pruebas de Sensibilidad MicrobianaRESUMEN
CONTEXT: The effects of reduced-dose schedules of 7-valent pneumococcal conjugate vaccine (PCV-7) on pneumococcal carriage in children are largely unknown, although highly relevant in the context of subsequent herd effects. OBJECTIVE: To examine the effects of a 2-dose and 2 + 1-dose PCV-7 schedule on nasopharyngeal pneumococcal carriage in young children compared with controls. DESIGN, SETTING, AND PATIENTS: A randomized controlled trial of nasopharyngeal carriage of Streptococcus pneumoniae enrolling 1003 healthy newborns and 1 of their parents in a general community in The Netherlands, with follow-up to age 24 months and conducted between July 7, 2005, and February 14, 2008. INTERVENTION: Infants were randomly assigned to receive 2 doses of PCV-7 at 2 and 4 months; 2 + 1 doses of PCV-7 at 2, 4, and 11 months; or no dosage (control group). MAIN OUTCOME MEASURE: Vaccine serotype pneumococcal carriage rates in infants in the second year of life. RESULTS: At 12 months, vaccine serotype pneumococcal carriage was significantly decreased after both PCV-7 schedules, with vaccine serotype pneumococcal carriage rates of 25% (95% confidence interval [CI], 20%-30%) and 20% (95% CI, 16%-25%) in the 2-dose and 2 + 1-dose schedule groups, respectively, vs 38% (95% CI, 33%-44%) in the control group (both P < .001). At 18 months, in the 2 + 1-dose schedule group, vaccine serotype pneumococcal carriage had further decreased to 16% (95% CI, 12%-20%) and, at 24 months, to 14% (95% CI, 11%-18%; both P < .001); whereas in the 2-dose schedule group, vaccine serotype pneumococcal carriage had remained stable at 18 months (24%; 95% CI, 20%-29%), but at 24 months had further decreased to 15% (95% CI, 11%-19%; both P < .001). In the control group, vaccine serotype pneumococcal carriage remained around 36% to 38% until 24 months. CONCLUSION: Compared with no pneumococcal vaccination, a 2 + 1-dose and 2-dose schedule of PCV-7 resulted in significant reductions of vaccine serotype pneumococcal carriage in the second year of life. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00189020.
Asunto(s)
Portador Sano/prevención & control , Nasofaringe/microbiología , Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas/administración & dosificación , Streptococcus pneumoniae/aislamiento & purificación , Preescolar , Vacuna Neumocócica Conjugada Heptavalente , Humanos , Esquemas de Inmunización , Lactante , Recién Nacido , Serotipificación , Streptococcus pneumoniae/clasificación , Vacunas ConjugadasAsunto(s)
Antígenos Virales/aislamiento & purificación , Inmunoensayo/métodos , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Brotes de Enfermedades , Femenino , Humanos , Lactante , Subtipo H1N1 del Virus de la Influenza A/inmunología , Gripe Humana/epidemiología , Gripe Humana/inmunología , Gripe Humana/virología , Masculino , Persona de Mediana Edad , Juego de Reactivos para Diagnóstico , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
A 24-year-old man was seen with position dependent chest pain and fever. Electrocardiography showed typical diffuse repolarisation changes matching with perimyocarditis. Local petechiae developed on the left leg and bloodcultures were positive for Neisseria meningitidis serogroup C, which provided the diagnosis perimyocarditis caused by Neisseria meningitidis.
Asunto(s)
Infecciones Meningocócicas/diagnóstico , Miocarditis/diagnóstico , Neisseria meningitidis Serogrupo C/aislamiento & purificación , Dolor en el Pecho/diagnóstico , Dolor en el Pecho/etiología , Humanos , Masculino , Adulto JovenRESUMEN
BACKGROUND: We recently showed that vaccination with a 7-valent pneumococcal conjugate vaccine (PCV7) followed by a 23-valent pneumococcal polysaccharide vaccine (PPSV23) failed to prevent new episodes of acute otitis media (AOM) in previously unvaccinated toddlers and children with a history of recurrent AOM. We describe in detail the impact of pneumococcal vaccinations on nasopharyngeal carriage of S. pneumoniae in this study population. METHODS: The impact of vaccination with PCV7 followed by PPSV23 on pneumococcal nasopharyngeal carriage was studied in a prospective, randomized trial involving 383 children (age range, 1-7 years) with previous AOM. Nasopharyngeal swab specimens were collected at the time of first vaccination and at 6-7-month intervals during the 26-month follow-up period. RESULTS: Overall, pneumococcal carriage rates did not diminish, remaining at approximately 50% in both PCV7/PPSV23 and control vaccinees. A significant shift from conjugate vaccine- to nonconjugate vaccine-type pneumococci was observed in children aged 1-2 years, who received the conjugate vaccine twice before the polysaccharide vaccine was administered. Conjugate vaccine serotype carriage was not influenced in older children, who received the conjugate vaccine once before receiving the polysaccharide booster. CONCLUSIONS: The administration of conjugate vaccines at least twice also after 2 years of age may be mandatory for reducing the carriage of conjugate vaccine serotypes in children with recurrent AOM. Polysaccharide booster vaccination did not affect nasopharyngeal colonization with serotypes not included in the conjugate vaccine.
Asunto(s)
Portador Sano/microbiología , Nasofaringe/microbiología , Otitis Media/complicaciones , Vacunas Neumococicas/inmunología , Streptococcus pneumoniae/aislamiento & purificación , Envejecimiento , Niño , Preescolar , Método Doble Ciego , Femenino , Humanos , Lactante , Masculino , Vacunas Conjugadas/inmunologíaRESUMEN
OBJECTIVES: Routine use of disk diffusion tests for detecting antibiotic resistance in Legionella pneumophila has not been described. The goal of this study was to determine the correlation of MIC values and inhibition zone diameter (MDcorr) in clinical L. pneumophila isolates. METHODS: Inhibition zone diameter of 183 L. pneumophila clinical isolates were determined for ten antimicrobials. Disk diffusion results were correlated with MICs as determined earlier with E-tests. RESULTS: Overall the correlation of MIC values and inhibition zone diameters (MDcorr) of the tested antimicrobials is good, and all antimicrobials showed a WT distribution. Of the tested fluoroquinolones levofloxacin showed the best MDcorr. All macrolides showed a wide MIC distribution and good MDcorr. The MDcorr for cefotaxim, doxycycline and tigecycline was good, while for rifampicin and moxifloxacin, they were not. CONCLUSION: Overall good correlation between MIC value and disk inhibition zone were found for the fluoroquinolones, macrolides and cefotaxim.
Asunto(s)
Antibacterianos/farmacología , Pruebas Antimicrobianas de Difusión por Disco , Legionella pneumophila/efectos de los fármacos , Enfermedad de los Legionarios/microbiología , Cefotaxima/farmacología , Farmacorresistencia Bacteriana , Fluoroquinolonas/farmacología , Humanos , Legionella pneumophila/aislamiento & purificación , Macrólidos/farmacología , Pruebas de Sensibilidad Microbiana , Estadísticas no ParamétricasRESUMEN
OBJECTIVES: The purpose of this study was to establish wild-type (WT) distributions and determine the epidemiological cut-off values (ECOFF) in clinical L. pneumophila serogroup 1 isolates for 10 antimicrobials commonly used for the treatment of Legionella infections using a method feasible in a routine clinical laboratory. METHODS: MICs of 183 clinical L. pneumophila serogroup 1 isolates, collected as part of an outbreak detection program, were tested using E-test methodology on buffered charcoal yeast extract agar supplemented with α-ketoglutarate (BCYE-α). The MICs were read after 2 days of incubation at 35 °C with increased humidity and without CO(2). ECOFFs were determined according to EUCAST methodology and expressed as WT ≤ X mg/L. RESULTS: All antimicrobials showed a WT distribution, although the width varied from 2 two-fold dilutions to 8 dilutions, depending on antibiotic class. The ECOFFs determined were 1.0 mg/L for ciprofloxacin, 0.50 mg/L for levofloxacin, 1.0 mg/L for moxifloxacin, 1.0 mg/L for erythromycin, 1.0 mg/L for azithromycin, 0.50 mg/L for clarithromycin, 1.0 mg/L for cefotaxime, 0.032 mg/L for rifampicin, 16 mg/L for tigecycline, and 8 mg/L for doxycycline. CONCLUSION: All isolates were inhibited by low concentrations of the fluoroquinolones and macrolides tested, with somewhat higher MICs for the fluoroquinolones. Rifampicin was found to be the most active against L. pneumophila isolates in vitro. These data can be used as a reference for the detection of resistance in clinical L. pneumophila isolates and as a setting of clinical breakpoints.
Asunto(s)
Antibacterianos/farmacología , Legionella pneumophila/efectos de los fármacos , Legionella pneumophila/aislamiento & purificación , Enfermedad de los Legionarios/microbiología , Pruebas de Sensibilidad Microbiana/métodos , Farmacorresistencia Bacteriana , HumanosRESUMEN
BACKGROUND: Seasonal rotavirus (RV) epidemics partly overlap with those of other common childhood infections, thereby generating enormous, but poorly quantified, pressure on hospital resources during winter and spring. We assessed RV contribution to seasonal excess in all-cause pediatric hospitalizations and RV hospitalization incidence rate in an observational study. METHODS: The study was conducted among pediatric wards in 3 general hospitals and 1 pediatric tertiary care center. Numbers of RV hospitalizations were determined from 5-year data on confirmed RV hospitalizations and adjusted for RV underreporting, assessed through active surveillance for acute gastroenteritis during the 2011 RV season. Incidence rate and RV contribution to all-cause hospitalizations were determined on hospital administrative data and population statistics. RESULTS: RV accounted for 6.2% (95% confidence interval: 5.3-7.1) of all-cause pediatric hospitalizations among general hospitals and 3.1% (95% confidence interval: 2.9-3.3) at the tertiary care center, adjusted for the proportion RV underreporting among gastroenteritis patients (33%) as observed during active surveillance. Among general hospitals, there was a 30% increase in all-cause hospitalizations during the active season of common childhood infections compared with summer months. RV contributed 31% to seasonal excess in all-cause pediatric hospitalizations, representing 12.9% of hospitalizations between January and May. RV hospitalizations incidence rate in the population was 510/100,000 child-years <5 years (95% confidence interval: 420-600). CONCLUSION: RV is one of the main causes of seasonal peaks in pediatric hospitalizations, and as such contributes significantly to periodic high bed capacity pressures and associated adverse effects. RV vaccination benefits in this respect should be considered in decision-making processes.