Yang Ree Kim

Epidemiology and risk factors for bacteremia in 144 consecutive living-donor liver transplant recipients.

Purpose Bacteremia is a major infectious complication associated with mortality in liver transplant recipients. The causative organisms and clinical courses differ between medical centers due to variations in regional bacterial epidemiology and posttransplant care. Further, living donors in Korea contribute to 83% of liver transplants, and individualized data are required to improve survival rates. Patients and Methods We retrospectively analyzed 104 subjects who had undergone living-donor liver transplant from 2005 to 2007. Results Among the 144 consecutive living-donor liver transplant recipients, 24% (34/144) developed bacteremia, 32% (46/144) developed non-bacteremic infections, and 44% (64/144) did not develop any infectious complications. Forty episodes of bacteremia occurred in 34 recipients. The major sources of bacteremia were intravascular catheter (30%; 12/40), biliary tract (30%; 12/40), and abdomen (22.5%; 9/40). Gram-positive cocci were more common (57.5%; 23/40) than Gram-negative rods (32.5 %; 13/40) and fungi (10%; 4/40). The data revealed that the following factors were significantly different between the bacteremia, non-bacteremic infection, and no infection groups: age (p = 0.024), posttransplant hemodialysis (p = 0.002), ICU stay (p = 0.012), posttransplant hospitalization (p < 0.0001), and duration of catheterization (p < 0.0001). The risk factors for bacteremia were older than 55 years (odds ratio, 6.1; p = 0.003), catheterization for more than 22 days (odds ratio, 4.0; p = 0.009), UNOS class IIA (odds ratio, 6.6; p = 0.039), and posttransplant hemodialysis (odds ratio, 23.1; p = 0.001). One-year survival rates in the bacteremic, non-bacteremic infection, and no infection groups were 73.2%, 91.3%, and 93.5%, respectively. Conclusion Early catheter removal and preservation of renal function should focus for improving survival after transplant.

Risk Factors for Mortality in Patients with Carbapenem-Resistant Acinetobacter baumannii Bacteremia: Impact of Appropriate Antimicrobial Therapy

This study investigated predictors associated with 14-day mortality, and focused especially on the impact of appropriate antimicrobial treatment among patients with carbapenem-resistant Acinetobacter baumannii (CRAB) bacteremia. This retrospective study was performed at a tertiary care hospital in Korea from June 2007 to June 2010. Antibiotic therapy was considered appropriate if the antibiotics were administered via an appropriate route within 24 hr after the result of blood culture, had in vitro sensitivity to isolated strains, and of an adequate dosage according to the current guidelines. Ninety-five patients with A. baumannii bacteremia were included; of these, 53 (55.8%) were infected with CRAB. The overall infection-related 14-day mortality was higher in patients receiving inappropriate antimicrobial therapy than in patients receiving appropriate therapy (59.5% [22/37] vs 13.8% [8/58], P < 0.05). Multivariate analysis showed that septic shock (OR 10.5, 95% CI, 1.93-57.4; P = 0.006), carbapenem-resistance (OR 7.29, 95% CI 1.57-33.8; P = 0.01), pneumonia as a source of bacteremia (OR 5.29, 95% CI 1.07-26.1; P = 0.04), and inappropriate antimicrobial therapy (OR 8.05, 95% CI 1.65-39.2; P = 0.009) were independent risk factors for 14-day mortality. Early definite antimicrobial therapy had an influence on favorable outcomes in patients with A. baumannii bacteremia.

Risk factors for mortality in patients with Pseudomonas aeruginosa bacteremia; retrospective study of impact of combination antimicrobial therapy

BackgroundWhether the combination of antimicrobial therapy is a factor in mortality in Pseudomonas aeruginosa bacteremia remains to be elucidated. This study investigated the risk factors for mortality in P. aeruginosa bacteremia patients and the influence of adequate antimicrobial therapy and combination therapy on clinical outcomes.MethodsThis retrospective study analyzed data of 234 patients with P. aeruginosa bacteremia at a 1,200-bed tertiary teaching university hospital in South Korea between January 2010 and December 2012. Factors associated with mortality were determined. Mortality was compared in patients with adequate empirical and targeted combination therapy, and monotherapy, and inappropriate therapy.ResultsA total of 141 (60.3%) patients were given appropriate empirical antibiotic treatment (combination therapy in 38 and monotherapy in 103). Among 183 patients (78.2%) who finally received appropriate targeted treatment, 42 had combination therapy and 141 had monotherapy. The percentage of patients receiving empirical combination therapy was slightly, but not significantly higher, in the survivor group than in the nonsurvivor group (17.0% [31/182] vs. 13.5% [7/52], p = 0.74). A similar tendency was demonstrated for targeted combination therapy (19.8% [36/182] vs. 11.5% [6/52], respectively; p = 0.31). However, in a subgroup analysis of data from patients (n = 54) with an absolute neutrophil count less than 500/mm3, the patients who had appropriate empirical or targeted combination therapy showed better outcomes than those who underwent monotherapy or inappropriate therapy (p < 0.05). Mechanical ventilation (odds ratio [OR], 6.93; 95% confidence interval [CI], 2.64–18.11; p = 0.0001), the use of a central venous catheter (OR, 2.95; 95% CI, 1.35–6.43; p = 0.007), a high Acute Physiology and Chronic Health Evaluation II score (OR, 4.65; 95% CI, 1.95–11.04; p = 0.0001), and presence of septic shock (OR, 2.91; 95% CI, 1.33–6.38; p = 0.007) were independent risk factors for 14-day mortality.ConclusionsDisease severity was a critical factor for mortality in our patients with P. aeruginosa bacteremia. Overall, combination therapy had no significant effect on 14-day mortality compared with monotherapy. However, appropriate combination therapy showed a favorable effect on survival in patients with febrile neutropenia.

Risk factors for vancomycin-resistant enterococci infection and mortality in colonized patients on intensive care unit admission

This study examined the incidence of and risk factors for development of vancomycin-resistant enterococci (VRE) infection and death in VRE-colonized patients in a medical intensive care unit. VRE colonization was identified in 184 patients (17.6%) in whom VRE perianal swab cultures were obtained. Of these, 28 (11.9%) developed VRE infection. Control of infectious sources is crucial to decrease development of VRE infections and optimize the survival of VRE-colonized patients.

Clinical Presentation and Outcomes of Middle East Respiratory Syndrome in the Republic of Korea.

Background From May to July 2015, the Republic of Korea experienced the largest outbreak of Middle East respiratory syndrome (MERS) outside the Arabian Peninsula. A total of 186 patients, including 36 deaths, had been diagnosed with MERS-coronavirus (MERS-CoV) infection as of September 30th, 2015. Materials and Methods We obtained information of patients who were confirmed to have MERS-CoV infection. MERS-CoV infection was diagnosed using real-time reverse-transcriptase polymerase chain reaction assay. Results The median age of the patients was 55 years (range, 16 to 86). A total of 55.4% of the patients had one or more coexisting medical conditions. The most common symptom was fever (95.2%). At admission, leukopenia (42.6%), thrombocytopenia (46.6%), and elevation of aspartate aminotransferase (42.7%) were observed. Pneumonia was detected in 68.3% of patients at admission and developed in 80.8% during the disease course. Antiviral agents were used for 74.7% of patients. Mechanical ventilation, extracorporeal membrane oxygenation, and convalescent serum were employed for 24.5%, 7.1%, and 3.8% of patients, respectively. Older age, presence of coexisting medical conditions including diabetes or chronic lung disease, presence of dyspnea, hypotension, and leukocytosis at admission, and the use of mechanical ventilation were revealed to be independent predictors of death. Conclusion The clinical features of MERS-CoV infection in the Republic of Korea were similar to those of previous outbreaks in the Middle East. However, the overall mortality rate (20.4%) was lower than that in previous reports. Enhanced surveillance and active management of patients during the outbreak may have resulted in improved outcomes.

Immunogenicity and Safety of Trivalent Inactivated Influenza Vaccine: A Randomized, Double-Blind, Multi-Center, Phase 3 Clinical Trial in a Vaccine-Limited Country

Influenza vaccines are the primary method for controlling influenza and its complications. This study was conducted as a phase 3, randomized, double-blind, controlled, multi-center trial at seven university hospitals to evaluate the immunogenicity and safety of an inactivated, split, trivalent influenza vaccine (GC501, Green Cross Corporation, Yongin, Korea), which was newly manufactured in Korea in 2008. Between September 21 and 26, a total of 329 healthy subjects were recruited for the immunogenicity analysis, while 976 subjects were enrolled for the safety analysis. The GC501 vaccine met both FDA and EMEA criteria with ≥ 80% of subjects achieving post-vaccination titers ≥ 40 for all three subtypes, even in the elderly. The vaccine was well tolerated with only mild systemic and local adverse events. In summary, GC501 showed excellent immunogenicity and a good safety profile in both young adults and the elderly. The licensure of GC501 might be an important basis in preparation for the future influenza pandemic.

Etiology and outcome of iliopsoas muscle abscess in Korea; changes over a decade

OBJECTIVES Iliopsoas muscle abscess (IPA) is considered a rare disease whose etiology has changed depending on the country and antibiotic selection pressure. This study evaluates the changes in etiology, clinical outcome, and risk factors for mortality for IPA. METHODS We reviewed the medical records of a total of 116 patients with IPA who were admitted to 4 university hospitals in Korea over the 11 years, and compared the etiology between 2001-2006 (period 1, n=44) and 2007-2012 (period 2, n=72). RESULTS Among 75 cases with a definitive microbial diagnosis, the predominant etiological organisms were S.aureus(45.3%), followed by M. tuberculosis(14.7%) and K.pneumoniae(9.3%). The percentage of MRSA in period 2 increased remarkably compared to period 1, from 25 % to 44.4%, and incidence of M.tuberculosis from 7.1% to 19.1, although these were not statistically significant. The overall mortality was 6.8% in period 1, and 13.9% in period 2, and sepsis as an initial manifestation (OR 293.5, CI 7.1 - 12034.4, P=0.003) and serum creatinine level (OR 0.43, CI 0.23 - 0.80, P=0.008) were independent predictors of mortality. Invasive procedure improved the prognosis in cases with microbiologic confirmed pyogenic psoas abscess (46/50 [92%] vs. 9/14 [64.3%], p=0.008). CONCLUSION The incidence of MRSA as a cause of IPA is on the increase. Although the overall prevalence of tuberculosis is decreasing, tuberculosis is still an important cause of IPA. Initial clinical status and invasive intervention can lead to favorable outcomes.

Virulence factors and clinical patterns of hypermucoviscous Klebsiella pneumoniae isolated from urine

Abstract Background: Klebsiella pneumoniae with hypermucoviscosity (HM) phenotype is generally more virulent than HM-negative strains. The aim of this study was to investigate the prevalence of HM phenotype among urinary isolates and to compare the virulence factors, antimicrobial susceptibility patterns and clinical characteristics of HM-positive and -negative K. pneumoniae isolated from urine of hospitalized patients. Methods: From June to October 2013, a total of 81 non-repetitive K. pneumoniae strains were isolated from urine. HM phenotype was determined by a string test. The K1 and K2 genotypes, the allS, kfu, rmpA, rmpA2 and wabG, aerobactin gene were detected by polymerase chain reaction. Results: Of the 81 K. pneumoniae isolates, 12.3% produced a positive string test. The aerobactin (80.0%[8/10] vs. 15.5%[11/71], p = .0001), allS (40.0%[4/10] vs. 9.9%[7/71], p = .009), rmpA (70.0%[7/10] vs. 14.1%[10/71], p = .0001) and rmpA2 (60.0%[6/10] vs. 16.9%[12/71], p = .002) genes were more prevalent in HM positive than in HM negative strains. The K1 (20.0%[2/10) vs. 8.5%[6/71]] and K2 (30.0%[3/10] vs. 4.2%[3/71]) capsular serotypes were more common in HM strains than in non-HM strains (p = .0001). HM-positive K. pneumoniae isolates were more susceptible to amoxicillin/clavulanic acid (p = .02), cefazolin (p = .03), cefotaxime (p = .02) and ciprofloxacin (p = .03) than HM-negative isolates. Multivariate analysis showed that HM phenotype (OR, 23.87; 95% CI, 3.91–145.4, p < .01) and age >60 years (OR, 8.33; 95% CI, 1.25–55.31, p = .03) were significant risk factors for concurrent bacteraemia. Conclusion: Klebsiella pneumoniae with expression of HM phenotype isolated from urine were more likely to be associated with concurrent bacteraemia than isolates without the HM phenotype, and were more susceptible to antibiotics. Physicians have to be aware of the possibility of bacteraemia in patients with K. pneumoniae bacteriuria, especially if strains are HM positive and the patient is >60 years old.

Emphysematous Osteomyelitis due to Escherichia coli

Emphysematous osteomyelitis, especially that involving the extra-axial skeleton, is an extremely rare presentation but associated with significant morbidity and mortality. Here, we report a case in which a 58-year-old female patient with diabetes mellitus presented with emphysematous osteomyelitis that involved the sternum, clavicle, and pelvic bone and was caused by Escherichia coli via hematogenous spread of urinary tract infection. We successfully treated her with urgent and aggressive surgical drainage with prolonged antibiotics therapy. Early diagnosis and immediate surgical intervention are required for better outcomes in cases of emphysematous osteomyelitis.

In-hospital contact investigation among health care workers after exposure to pulmonary tuberculosis in an intermediate tuberculosis prevalence area: A prospective study

ABSTRACT We carried out in-hospital contact investigations of patients with pulmonary tuberculosis and analyzed the prevalence of latent tuberculosis infection (LTBI) among health care workers (HCWs) after TB exposure. A prospective study was conducted of 872 HCWs who were exposed to 55 index cases diagnosed with active pulmonary TB. HCWs after TB exposure were evaluated both TST and chest X-ray at the time of enrollment and 12 weeks after exposure; 625 HCWs (71.6%) underwent both initial assessments; 41 HCWs (6.6%) had a positive TST result. After 12 weeks, 71.1% of HCWs with initial negative TST (n = 415) underwent a second assessment. Ten HCWs had TST conversion. One HCW (0.2%) developed active pulmonary TB. In multivariable analysis, age over 30 years was associated with TST conversion (p = .02). Point prevalence of latent TB was 6.6%, and incidence of LTBI was estimated as 2.4 per 100 HCWs. Strict infection control measures should be emphasized in intermediate TB-burden, BCG-vaccinated countries, especially in HCWs with high risk for TB exposure.