RESUMEN
We report on the incidence, risk factors, and outcome of late Staphylococcus aureus bacteremia (SAB) in a cohort of 709 adult and pediatric patients at Memorial Sloan-Kettering Cancer Center between September 1999 and December 2006. The SAB cases were identified by prospective surveillance and examination of a computerized database. Late SAB was defined as SAB occurring > 50 days post-hematopoietic stem cell transplantation (HSCT). A nested case-controlled study was conducted to identify predictors of late SAB. The incidence of late SAB was 6/100,000 patient-days. The median time from stem cell infusion to incident blood culture was 137 days (range, 55 to 581 days). Eighty-four percent of the cases were community acquired; 40% involved a focal infection. Bacteremia was persistent (>3 days) despite removal of endovascular access in > 50% of cases. Risk factors for late SAB were acute graft-versus-host disease (aGVHD) flare, acute or chronic skin GVHD (cGVHD), corticosteroid use, liver dysfunction, and prolonged hospital length of stay (LOS) post-HSCT. In multivariate models, skin GVHD (P = .002) and LOS (P = .02) remained significant. The median survival post-SAB was 135 days (range, 1 to 1765 days). Late SAB occurred mainly in the setting of GVHD or corticosteroid therapy. Clinical manifestations were highly variable. Multiple comorbidities, indicated by organ dysfunction and hospitalization, likely contributed to persistence and increased morbidity and mortality. We recommend a high index of suspicion and empiric antistaphylococcal treatment pending culture results in high-risk patients undergoing HSCT.
Asunto(s)
Bacteriemia/mortalidad , Trasplante de Células Madre Hematopoyéticas , Infecciones Estafilocócicas/mortalidad , Staphylococcus aureus , Enfermedad Aguda , Adolescente , Corticoesteroides , Adulto , Anciano , Bacteriemia/tratamiento farmacológico , Niño , Preescolar , Enfermedad Crónica , Supervivencia sin Enfermedad , Femenino , Enfermedad Injerto contra Huésped/microbiología , Enfermedad Injerto contra Huésped/mortalidad , Enfermedad Injerto contra Huésped/prevención & control , Neoplasias Hematológicas/microbiología , Neoplasias Hematológicas/terapia , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Infecciones Estafilocócicas/tratamiento farmacológico , Tasa de Supervivencia , Factores de Tiempo , Trasplante HomólogoRESUMEN
Toll-like receptors (TLRs) transmit signals in response to Aspergillus fumigatus conidia and hyphae. In this preliminary study, we examined the association between single nucleotide polymorphisms (SNPs) in TLR1, TLR4, and TLR6 genes and development of invasive aspergillosis (IA) in 127 allogeneic hematopoietic stem cell transplant recipients consisting of 22 patients with IA and 105 unaffected control subjects. The following SNPs and their pairwise interactions were considered in the model: TLR1 (239G > C, 743A > G, 914A > T, 1805G > T), TLR4 (896A > G, 1196C > T), and TLR6 (359T > C, 745C > T, 764C > T). No association was found between donor SNP and the risk of IA. Analysis of recipient SNP data showed that the presence of TLR1 239G > C (Arg80 > Thr) or the presence of both TLR1 743A > G (Asn248 > Ser) and TLR6 745C > T (Ser249 > Pro) is associated with IA (odds ratio = 1.30, 95% confidence interval = 1.13 to 1.50; P < .001). Further analyses using a prospective cohort may enable us to identify TLR polymorphisms associated with the susceptibility to IA within a defined interval among immunocompromised patients.
Asunto(s)
Aspergilosis/genética , Predisposición Genética a la Enfermedad , Trasplante de Células Madre Hematopoyéticas , Enfermedades Pulmonares Fúngicas/genética , Polimorfismo de Nucleótido Simple , Receptor Toll-Like 1/genética , Receptor Toll-Like 6/genética , Alelos , Sustitución de Aminoácidos/genética , Sustitución de Aminoácidos/inmunología , Aspergilosis/inmunología , Análisis Mutacional de ADN , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Humanos , Modelos Logísticos , Enfermedades Pulmonares Fúngicas/inmunología , Estudios Prospectivos , Estudios Retrospectivos , Trasplante HomólogoRESUMEN
The study aimed to determine the natural history of Staphylococcus aureus nasal colonization in hemodialysis outpatients. Surveillance cultures were taken from patients presenting for hemodialysis or routine care to identify S. aureus nasal carriers. A prospective cohort study was performed to identify risks for persistent colonization. Detailed microbiologic and molecular studies of colonizing isolates were performed. Only 23/145 (15.9%) dialysis patients were persistently colonized, and only HIV-positive status was associated with persistence (P = 0.05). Prior hospitalization was the only risk factor for methicillin-resistant S. aureus carriage (OR 2.5, P = 0.03). In isolates from patients with ≤ 42 days of vancomycin exposure, vancomycin minimum bactericidal concentrations (MBCs) increased with duration of exposure. Among dialysis patients, S. aureus colonization was limited and transient; only HIV status was associated with persistence. Nevertheless, duration of vancomycin exposure was associated with increasing vancomycin MBCs. Vancomycin exposure in S. aureus carriers may be involved in increasing resistance.