Jang Wook Sohn

Predictors of persistent methicillin-resistant Staphylococcus aureus bacteraemia in patients treated with vancomycin

OBJECTIVES The high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) coupled with an increase in vancomycin use have induced vancomycin tolerance in MRSA, adversely affecting the outcome of MRSA bacteraemia. This study aimed to identify predictors of persistent MRSA bacteraemia (PMRSAB) in patients treated with vancomycin. METHODS A retrospective, case-control study was performed at a university hospital in Korea from January 2006 to February 2009. Subjects included 96 patients who had MRSA bacteraemia and received vancomycin under therapeutic drug monitoring. We compared the clinical characteristics, management and outcomes of cases with PMRSAB (>or=7 days, n = 31) with controls with non-PMRSAB (<or=3 days, n = 32). Vancomycin MICs were determined by the Vitek 2 system. RESULTS Of 96 patients with MRSA bacteraemia, MRSA isolates from 21 patients (21.9%) showed a vancomycin MIC of 2 mg/L. Independent predictors of PMRSAB were: retention of implicated medical devices [odds ratio (OR), 10.35; 95% confidence interval (CI), 1.03-104.55]; MRSA infection of at least two sites (OR, 10.24; 95% CI, 1.72-61.01); and vancomycin MIC of 2 mg/L (OR, 6.34; 95% CI, 1.21-33.09). The frequency of side effects and mean trough serum vancomycin concentrations were not significantly different between the two groups. Sixteen patients with PMRSAB subsequently received teicoplanin +/- arbekacin, linezolid or quinupristin/dalfopristin, due to vancomycin failure or intolerance. CONCLUSIONS To minimize the risk of PMRSAB, early removal of implicated devices and evaluation for metastatic infections should be encouraged. Alternative antibiotic therapy is warranted for infections due to isolates with elevated vancomycin MICs, as well as for the high rates of side effects.

An outbreak of post-acupuncture cutaneous infection due to Mycobacterium abscessus

BackgroundDespite the increasing popularity of acupuncture, the importance of infection control is not adequately emphasized in Oriental medicine. In December 2001, an Oriental medical doctor in Seoul, South Korea, encountered several patients with persistent, culture-negative skin lesions on the trunk and extremities at the sites of prior acupuncture treatment. We identified and investigated an outbreak of Mycobacterium abscessus cutaneous infection among the patients who attended this Oriental medicine clinic.MethodsPatients were defined as clinic patients with persistent cutaneous infections at the acupuncture sites. Medical records for the previous 7 months were reviewed. Clinical specimens were obtained from the patients and an environmental investigation was performed. M. abscessus isolates, cultured from patients, were compared by pulsed-field gel electrophoresis (PFGE).ResultsForty patients who attended the Oriental medicine clinic and experienced persistent cutaneous wound infections were identified. Cultures from five of these patients proved positive, and all other diagnoses were based on clinical and histopathologic examinations. All environmental objects tested were negative for M. abscessus, however, most were contaminated by various nosocomial pathogens. Molecular analysis using PFGE found all wound isolates to be identical.ConclusionWe have identified a large outbreak of rapidly growing mycobacterial infection among patients who received acupuncture at a single Oriental medicine clinic. Physicians should suspect mycobacterial infections in patients with persistent cutaneous infections following acupuncture, and infection control education including hygienic practice, should be emphasized for Oriental medical doctors practicing acupuncture.

Red blood cell transfusions are associated with lower mortality in patients with severe sepsis and septic shock: a propensity-matched analysis*.

Objectives:To evaluate the effects of transfusions in patients with severe sepsis and septic shock on mortality. Design:Propensity-matched analysis of a prospective observational database (April 2005 to February 2009). Setting:Twenty-two medical and surgical intensive care units in 12 teaching hospitals in Korea. Patients:One thousand fifty-four patients with community-acquired severe sepsis and septic shock. InterventionsNone. Measurements and Main Results:Of the 1,054 patients, 407 (38.6%) received a blood transfusion. The mean pretransfusion hemoglobin level was 7.7 ± 1.2 g/dL. Transfused patients had higher 28-day and in-hospital mortality rates (32.7% vs. 17.3%; p < .001, 41.3% vs. 20.3%; p < .001, respectively) and a longer duration of hospital stay (21 [interquartile range, 10–35] vs. 13 [interquartile range, 8–24] days; p < .001), but were more severely ill at admission (lower systolic blood pressure, higher Acute Physiology and Chronic Health Evaluation II score, and Sequential Organ Failure Assessment score at admission). In 152 pairs matched according to the propensity score depending on patient transfusion status, transfused patients had a lower risk of 7-day (9.2% vs. 27.0%; p < .001), 28-day (24.3% vs. 38.8%; p = .007), and in-hospital mortality rates (31.6% vs. 42.8%; p = .044). After adjusting for blood transfusion as a time-dependent variable in multivariable analysis, blood transfusion was independently associated with lower risk of 7-day (hazard ratio 0.42, 95% confidence interval 0.19–0.50, p = .026), 28-day (hazard ratio 0.43, 95% confidence interval 0.29–0.62, p < .001), and in-hospital mortality (hazard ratio 0.51, 95% confidence interval 0.39–0.69, p < .001). Conclusions:In this observational study of patients with community-acquired severe sepsis and septic shock, red blood cell transfusions were associated with lower risk of mortality.

Clinical outcome and predictive factors of recurrence among patients with Kikuchi's disease.

OBJECTIVES To evaluate the clinical outcome and predictive factors of recurrence among patients with Kikuchis disease. METHODS Between January 2001 and December 2006, all patients with Kikuchis disease were included in the study. Data were collected on co-morbidities, clinical manifestations, and ultrasound/laboratory findings, and the differences were compared between recurrent disease and non-recurrent disease groups. RESULTS The study included 102 patients with a mean age of 26.7 years. Among these patients, three developed systemic lupus erythematosus during the follow-up period, while two cases were later associated with tuberculosis. Eight patients (7.8%) experienced early relapse and 13 (12.7%) showed late recurrence. Patients with recurrent episodes were more likely to have fever and fatigue with extranodal involvement. Compared to the non-recurrent cases, recurrent cases remained symptomatic for a rather longer duration. The positive rate of the fluorescence anti-nuclear antibody (FANA) test was significantly higher in the recurrent disease group compared to the non-recurrent disease group. CONCLUSIONS Kikuchis disease took a self-limiting clinical course in most cases, but the recurrence rate found in the present study was higher than that of previous reports. Kikuchis disease might be a phenotype of diverse disease entities. The prognosis is different according to the underlying cause. The FANA test would be useful in predicting recurrence.

Prognostic Significance of Infection Acquisition Sites in Spontaneous Bacterial Peritonitis: Nosocomial versus Community Acquired

Spontaneous bacterial peritonitis (SBP) is an ascitic fluid infection as a complication of end stage liver disease. The outcome is related to the severity of hepatorenal function, gastrointestinal bleeding, and many others; however it is not well known whether the infection acquisition sites have an effect on the prognosis of SBP. In order to identify the prognostic significance of the acquisition sites, we studied 106 patients who were diagnosed as culture positive SBP between October 1998 and August 2003. Thirty-two episodes were nosocomial and 74 were community acquired. Gram-negative bacilli such as Escherichia coli were dominant in both of the nosocomial and community-acquired SBPs. Despite significantly higher resistance to cefotaxime in nosocomial isolates compared to community-acquired isolates (77.8% vs. 13.6%, p=0.001), no difference was found regarding short or long term prognosis. Infection acquisition sites were not related to short or long term prognosis either. Shock, gastrointestinal bleeding and renal dysfunction were related to short term prognosis. Only Child-Pugh class C was identified as an independent prognostic factor of long-term survival.

Atypical pathogens as etiologic agents in hospitalized patients with community-acquired pneumonia in Korea: a prospective multi-center study.

Local epidemiologic data on the etiologies of patients hospitalized with community-acquired pneumonia (CAP) is needed to develop guidelines for clinical practice. This study was conducted prospectively to determine the proportion of atypical bacterial pathogens in adults patients hospitalized with CAP in Korea between October 2001 and December 2002. Microbiological diagnosis was determined by serology for antibodies to Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila. Nucleic acid of M. pneumoniae and C. pneumoniae in respiratory samples and Legionella antigen in urine samples were detected. The study population consisted of 126 patients (71 males, 55 females), averaging 54.6 yr (SD±17.8), whose paired sera were available. An etiologic diagnosis for atypical pathogens was made in 18 patients (14.3%): C. pneumoniae 9 (7.1%), M. pneumoniae 8 (6.3%), and L. pneumophila 3 patients (2.4%). Streptococcus preumoniae and other typical pathogens were isolated from 36 patients (28.6%). Of 126 patients, 16 (12.7%) were admitted to intensive care unit and atypical pathogens were identified in 5 patients (31.3%). Initial clinical features of patients with pneumonia due to atypical, typical or undetermined pathogens were indistinguishable. We conclude that atypical pathogens should be seriously considered in hospitalized patients with CAP, when initiating empiric treatment in Korea.

Control of extended-spectrum β-lactamase-producing Klebsiella pneumoniae using a computer-assisted management program to restrict third-generation cephalosporin use

OBJECTIVES The aim of this study was to evaluate the control of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae and antimicrobial resistance through a computerized antibiotic control program. METHODS An ambidirectional intervention study was conducted at a 750-bed university hospital in Korea from February 2004 to April 2006. In November 2004, hospital-wide restriction of third-generation cephalosporin use was integrated into a pre-existing computerized antibiotic prescription program that included an approval system for 15 antimicrobials. The proportions of ESBL-producing K. pneumoniae and other multidrug-resistant clinical isolates were compared during three phases (9 months per phase): Phase I (pre-intervention), Phase II (intensive-intervention) and Phase III (maintenance). RESULTS Third-generation cephalosporin use decreased significantly from 103.2 to 84.9 antibiotic use density (AUD, defined daily dose/1000 patient-days) between Phase I and Phase II (P< 0.05), whereas use of carbapenems and beta-lactam/beta-lactamase inhibitors increased from 14.5 to 18.2 AUD and from 53.3 to 62.6 AUD, respectively. The proportion of ESBL-producing K. pneumoniae isolates increased significantly from 8.1% (47/578) in Phase I to 32.0% (188/587) in Phase II, and then decreased significantly to 20.6% (97/470) in Phase III (P < 0.05). In addition, the proportions of imipenem- or piperacillin/tazobactam-resistant Pseudomonas aeruginosa and Acinetobacter baumannii isolates decreased significantly over the same period (P < 0.05). CONCLUSIONS The computerized antibiotic control program appears to be an effective tool for modifying antibiotic consumption, which may in turn prevent the spread of resistant pathogens.

Outcome and management of spinal tuberculosis according to the severity of disease: a retrospective study of 137 adult patients at Korean teaching hospitals.

Study Design. A retrospective study examining the clinical features, management, and treatment outcome of patients with spinal tuberculosis (TB). Objective. To determine the influence of disease severity and treatment modality on outcome of patients with spinal TB. Summary of Background Data. Although anti-TB chemotherapy is now the mainstay treatment for spinal TB, it may not be applicable to all situations, especially in patients with risk of deformity, instability, and progression of neurologic deficit. Methods. In this retrospective study (1994–2003), medical records and radiographic findings of patients with spinal TB were reviewed at 7 teaching hospitals in South Korea. The duration of triple chemotherapy with isoniazid, rifampin, and ethambutol, disease severity, operative procedures, and outcome were analyzed. The outcome was assessed as both favorable and unfavorable according to predefined criteria. Results. A total of 137 patients were diagnosed with spinal TB during the study period. Twenty-one patients were lost to follow-up and excluded from analysis. The mean age was 44.07 ± 16.57 years. The most common vertebral area involved was the lumbar (44.8%). The mean number of vertebra involved was 2.25. The mean angle of kyphosis was 21.58°. Forty-seven patients (35.1%) had severe symptoms. Radical surgery was carried out in 84 (62.2%) patients. Twenty patients were treated with short-term chemotherapy, while 96 under long-term. At the end of chemotherapy, 94 patients had achieved a favorable status and 22 an unfavorable one. Statistically, there was no significant difference between the 2 groups in terms of gender, chemotherapy duration, or the severity of spinal TB; however, age (P = 0.025; odds ratio = 0.963; 95% confidence interval 0.932–0.995) and radical surgery (P = 0.043; odds ratio = 3.047; 95% confidence interval 1.038–8.942) were significantly related to a favorable outcome by logistic analysis. Conclusions. Our results showed that a younger age and radical surgery in conjunction with anti-TB chemotherapy were significant favorable prognostic factors.

Nosocomial Outbreak of Carbapenem-Resistant Acinetobacter baumannii in Intensive Care Units and Successful Outbreak Control Program

Acinetobacter baumannii has been increasingly reported as a significant causative organism of various nosocomial infections. Here we describe an outbreak of carbapenem-resistant A. baumannii (CRAB) in the ICUs of a Korean university hospital, along with a successful outbreak control program. From October 2007 through July 2008, CRAB was isolated from 57 ICU patients. Nineteen patients were diagnosed as being truly infected with CRAB, four of whom were presumed to have died due to CRAB infection, producing a case-fatality rate of 21.1%. In surveillance of the environment and the healthcare workers (HCWs), CRAB was isolated from 24 (17.9%) of 135 environmental samples and seven (10.9%) of 65 HCWs. The pulsed field gel electrophoresis patterns showed that the isolates from patients, HCWs, and the environment were genetically related. Control of the outbreak was achieved by enforcing contact precautions, reducing environmental contamination through massive cleaning, and use of a closed-suctioning system. By August 2008 there were no new cases of CRAB in the ICUs. This study shows that the extensive spread of CRAB can happen through HCWs and the environmental contamination, and that proper strategies including strict contact precautions, massive environmental decontamination, and a closed-suctioning system can be effective for controlling CRAB outbreaks.

Epidemiological and genetic analysis of a sustained community-wide outbreak of hepatitis A in the Republic of Korea, 2008: A hospital-based case–control study

BACKGROUND The epidemiological shift of hepatitis A has contributed to a sustained community-wide outbreak in Korea during 2008. OBJECTIVES To assess the risk factors associated with hepatitis A virus (HAV) propagation, and to analyze the circulating genotype in the sustained community-wide outbreak. STUDY DESIGN The hospital-based case-control study was conducted in an 850-bed university hospital in Seoul from April to August, 2008. For molecular analysis of HAV isolates, a 488-bp gene fragment of the VP1 region was amplified and sequenced. RESULTS In the multivariated logistic regression model, the risk factors of HAV infection adjusted by age were contacts with hepatitis A case (OR 3.98, 95% CI: 1.36-11.66), residence with child aged <or=5 years (OR 3.43, 95% CI: 1.32-8.87), consuming uncooked lettuce (OR 3.98, 95% CI: 1.83-8.68) or carrot (OR 2.38, 95% CI: 2.38-5.09), drinking tap water (OR 3.68, 95% CI: 1.62-8.37) or portable spring water (OR 2.71, 95% CI: 1.11-6.62) supplied by water purifiers, and eating out (OR 3.87, 95% CI: 1.53-9.78). All isolates analyzed belonged to genotype IIIA. There were 42 nucleotide differences in the sequenced VP1 region among the isolates. Amino acid sequences were identical with each other. CONCLUSIONS Our study suggests that sporadically contaminated food- or water-borne sources as well as person-to-person transmission might lead a sustained community-wide HAV outbreak and pre-existing dominant genotype IA might be replaced with genotype IIIA as a major epidemic strain in Korea. Our findings urge the health authority to make public guidelines for HAV vaccination and outbreak control.