ABSTRACT
BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE), especially those that produce Klebsiella pneumoniae carbapenemase (KPC) and are associated with colistin resistance, pose a severe health threat due to the limited treatment options. AIM: To describe two outbreaks of KPC-producing K. pneumoniae in an adult intensive care unit (AICU) in Brazil. In May 2015, 14 patients had colistin-susceptible KPC-producing strains (ColS-KPC), and in July 2015, nine patients had colistin-resistant KPC-producing strains (ColR-KPC). METHODS: Between September 2014 and August 2015, we performed surveillance at a university hospital and all CRE were tested for blaKPC genes. Clonality was investigated by pulsed-field gel electrophoresis. Resistance to colistin was confirmed by broth microdilution method. Consumption of carbapenems and colistin was expressed as defined daily doses. FINDINGS: In all, 111 patients with CRE were identified during the surveillance period; K. pneumoniae was the major isolate (77.13%). The two outbreaks were identified when infection rates (KPC per 1000 patient-days) exceeded the background level. Rates of carbapenem and colistin consumption were high. Control measures (bedside alcohol gel, contact precautions, regular rectal swabs) did not curtail the outbreaks. Mortality rates were 42.9% and 44.4% for ColS-KPC- and ColR-KPC-infected patients, respectively. After the death of four infected patients with ColR-KPC, the unit was closed to new admissions. CONCLUSION: Our experience demonstrates the serious risks presented by KPC, and especially ColR-KPC, in Brazilian AICUs. Selective pressure from excessive antibiotic use and transmission on healthcare workers' hands were likely the major factors in transmission.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Colistin/pharmacology , Disease Outbreaks , Intensive Care Units , Klebsiella Infections/epidemiology , Klebsiella pneumoniae/drug effects , beta-Lactamases/metabolism , Adolescent , Adult , Aged , Aged, 80 and over , Brazil/epidemiology , Electrophoresis, Gel, Pulsed-Field , Female , Hospitals, University , Humans , Infant , Klebsiella Infections/microbiology , Klebsiella pneumoniae/classification , Klebsiella pneumoniae/enzymology , Klebsiella pneumoniae/isolation & purification , Male , Microbial Sensitivity Tests , Middle Aged , Molecular Typing , Young AdultABSTRACT
This paper presents a unified mathematical derivation of the asymptotic behaviour of the three main forms of partial directed coherence (PDC). Numerical examples are used to contrast PDC, gPDC (generalized PDC) and iPDC (information PDC) as to meaning and applicability and, more importantly, to show their essential statistical equivalence insofar as connectivity inference is concerned.
Subject(s)
Algorithms , Models, Biological , Models, Statistical , Computer SimulationABSTRACT
PURPOSE: Breast-conserving surgery and definitive radiation as an alternative to mastectomy is a well-accepted practice. However, there is limited information addressing the extent of surgical resection. The purpose of this study is to compare the outcome of patients treated with local excision or quadrantectomy, followed by definitive radiation with particular emphasis on local-regional control and cosmetic results. METHODS AND MATERIALS: Between 1978 and 1989, 425 patients with Stage I and II breast cancer underwent conservative surgery followed by definitive radiation. Fifty-four patients had a local excision and 371 had a quadrantectomy. Median follow-up was 42 months. Axillary dissection (levels I/II) was performed in 317 patients, and of these 126 patients had positive axillary lymph nodes. Radiation consisted of 4500-5000 cGy to the breast with Co60 or 4 MV photons, plus a boost to the tumor site (356/425 patients) for a total dose of 6000-6500 cGy. Treatment of the regional lymph nodes was given to patients with undissected or inadequately dissected axillas and usually to patients with multiple positive lymph nodes. Of the patients with positive lymph nodes, 46% received systemic chemotherapy. RESULTS: The 5-year actuarial freedom from local-regional recurrence rates for patients treated with local excision and quadrantectomy followed by definitive radiation were 92% and 93%, respectively (p = 0.7). The 5-year actuarial survival rates for local excision and quadrantectomy were as follows: overall (83% and 82%; p = 0.7), cause-specific disease-free (74% and 71%; p = 0.9), and distant disease-free (82% and 76%, p = 0.4). Estimated 10-year results are also presented. Cosmetic analysis required a minimum follow-up of 5 years. In the local excision, 77% of the patients had excellent-good result, compared to 53% following quadrantectomy (p = 0.03). Excluding patients who received chemotherapy, the excellent-good scores were 76% and 57%, respectively (p = 0.1). The most unfavorable cosmetic results were associated with quadrantectomy followed by radiation with boost dose and chemotherapy, excellent-good in 22%. CONCLUSION: Conservative surgery consisting of local excision or quadrantectomy resulted in comparable local-regional control, overall, disease-free and distant disease-free survival, although cosmetic results were superior in the local excision group.
