Ji Yun Noh

Colistin and rifampicin combination in the treatment of ventilator-associated pneumonia caused by carbapenem-resistant Acinetobacter baumannii

f VRE. A quantitative drug usage evaluation performed ndependently in our hospital from 2004 to 2006 revealed 104% increase in vancomycin usage. The qualitative rug usage evaluation results indicated that only 40% of he patients were prescribed vancomycin for one of the pproved indications according to the Hospital Infection ontrol Practices Advisory Committee (HICPAC) guidelines 7]. Having a malignant disease remained protective for RE in the multivariate model (OR 0.26, 95% CI 0.07– .97). The crude associated mortality rate was higher in atients with VRE infections (VRE 53.1% vs. VSE 32.3%; = 0.047). The total hospital stay (VRE 51.5 ± 27.8 days vs. SE 37.6 ± 29.6 days) was longer in VRE-infected patients han in those with VSE infections (P = 0.028).

Effectiveness of the pandemic influenza A/H1N1 2009 monovalent vaccine in Korea

The 2009 influenza pandemic was caused by a novel triple-reassortant influenza A/H1N1 virus that was further recombined with a Eurasian pig flu virus. Vaccination is a key countermeasure for disease; however, little data assessing vaccine effectiveness (VE) against the pandemic H1N1 virus are available. We conducted a matched case-control study to assess effectiveness of the 2009 influenza A/H1N1 monovalent vaccine against laboratory-confirmed, medically attended influenza patients. Subjects included in the study were ≥ 10 years of age and were treated at five university hospitals in the Republic of Korea (ROK) from December 2009 through March 2010. For subjects visiting outpatient clinics with influenza-like illness (ILI), real time reverse transcription polymerase chain reaction (rRT-PCR) was used to diagnose 2009 H1N1 influenza virus infection. Subjects with positive rRT-PCR were classified as cases, while those testing negative were controls. A valid vaccination corresponded to ≥ 14 days between receiving a dose of vaccine and symptom onset. Overall, 416 ILI subjects were analyzed, and 60 (14.4%) were vaccinated with the 2009 influenza A/H1N1 monovalent vaccine. The overall VE against pandemic 2009 A/H1N1 virus illness after adjustment for age group and presence of chronic medical conditions was 73.4% (95% confidence interval [CI]=49.1-86.1%). Both vaccine formulations (unadjuvanted and MF-59 adjuvanted) showed a statistically significant VE. In conclusion, the 2009 influenza A/H1N1 monovalent vaccine was substantially protective against pandemic influenza in the ROK during the 2009-2010 season.

Immunogenicity and Safety of the Influenza A/H1N1 2009 Inactivated Split-Virus Vaccine in Young and Older Adults: MF59-Adjuvanted Vaccine versus Nonadjuvanted Vaccine

ABSTRACT Since initial reports in April 2009, the pandemic influenza A (H1N1) virus has spread globally. Influenza vaccines are the primary method for the control of influenza and its complications. We conducted a multicenter clinical trial to evaluate the immunogenicity and safety of H1N1 vaccine (Green Cross Co.) in young adults (18 to 64 years) and the elderly (≥65 years) using a two-dose regimen, with the doses administered 21 days apart. Three different regimens of hemagglutinin antigen were comparatively analyzed: 3.75 μg (MF59 adjuvanted) versus 7.5 μg (MF59 adjuvanted) versus 15 μg (nonadjuvanted) in young adults and 3.75 μg (MF59 adjuvanted) versus 7.5 μg (MF59 adjuvanted) in the elderly. In young adults, all three vaccine regimens met the European Agency for the Evaluation of Medicinal Products (EMA) criteria after the first dose. In the elderly, on day 21 after the first dose, the rates of seroprotection and seroconversion were significantly higher for the 7.5-μg dose of MF59 adjuvanted vaccine than for the 3.75-μg dose (58.0% versus 44.3% [P = 0.03] and 53.7% versus 37.2% [P < 0.01], respectively). After the second dose, the geometric mean titer (GMT) increment was blunted with a 15-μg dose of nonadjuvanted vaccine, whereas the GMT increased about 2-fold with MF59 adjuvanted vaccines. In conclusion, a single 7.5-μg dose of MF59 adjuvanted vaccine would have a practical advantage over a two-dose, 3.75-μg, MF59 adjuvanted vaccine priming schedule. Following a two-dose priming schedule, the increase in hemagglutinin inhibition titers was higher with MF59 adjuvanted vaccine than with nonadjuvanted vaccine.

Vancomycin-resistant Enterococcus colonization before admission to the intensive care unit: A clinico-epidemiologic analysis

BACKGROUND Asymptomatic vancomycin-resistant Enterococcus (VRE) colonization is known to precede actual infection. Since VRE was first isolated in Korea in 1992, the VRE isolation rate has rapidly increased in tertiary hospitals. METHODS We performed a prospective observational study to estimate the prevalence of VRE colonization among inpatients at the time of intensive care unit (ICU) admission. From March through December 2007, rectal swab cultures were taken in all patients admitted to the ICU. We aimed to identify the risk factors for VRE colonization on admission. RESULTS During the study period, 34 (4.4%) out of 780 patients were already colonized with VRE before ICU admission: 21 out of 323 patients from general wards (6.5%) and 13 out of 437 patients from outside the hospital (2.97%). VRE-colonized patients were more likely than uncolonized patients to have infectious diseases and to have been referred from outside hospitals (P < .01). Previous hospitalization (P = .01) and antibiotic exposure (P < .01) were risk factors for VRE colonization before ICU admission. Pulsed-field gel electrophoresis patterns were diverse. Initial VRE colonization correlated to poor prognosis. CONCLUSION VRE colonization rate was not negligible among newly admitted ICU patients, suggesting that an active surveillance program focusing on high-risk groups may be helpful.

A Comparison of the Clinical and Epidemiological Characteristics of Adult Patients with Laboratory-Confirmed Influenza A or B during the 2011–2012 Influenza Season in Korea: A Multi-Center Study

Background During the 2011/2012 winter influenza season in the Republic of Korea, influenza A (H3N2) was the predominant virus in the first peak period of influenza activity during the second half of January 2012. On the other hand, influenza B was the predominant virus in the second peak period of influenza activity during the second half of March 2012. The objectives of this study were to compare the clinical and epidemiological characteristics of patients with laboratory-confirmed influenza A or influenza B. Methodology/Principal Findings We analyzed data from 2,129 adult patients with influenza-like illnesses who visited the emergency rooms of seven university hospitals in Korea from October 2011 to May 2012. Of 850 patients with laboratory-confirmed influenza, 656 (77.2%) had influenza A (H3N2), and 194 (22.8%) influenza B. Age, and the frequencies of cardiovascular disorders, diabetes, hypertension were significantly higher in patients with influenza A (H3N2) (P<0.05). The frequencies of leukopenia or thrombocytopenia in patients with influenza B at initial presentation were statistically higher than those in patients with influenza A (H3N2) (P<0.05). The rate of hospitalization, and length of hospital stay were statistically higher in patients with influenza A (H3N2) (P<0.05), and of the 79 hospitalized patients, the frequency of diabetes, hypertension, cases having at least one of the comorbid conditions, and the proportion of elderly were significantly higher in patients with influenza A (H3N2) (P<0.05). Conclusions The proportion of males to females and elderly population were significantly higher for influenza A (H3N2) patients group compared with influenza B group. Hypertension, diabetes, chronic lung diseases, cardiovascular disorders, and neuromuscular diseases were independently associated with hospitalization due to influenza. Physicians should assess and treat the underlying comorbid conditions as well as influenza viral infections for the appropriate management of patients with influenza.

Clinical and microbiological characterization of carbapenem-resistant Acinetobacter baumannii bloodstream infections

The incidence of carbapenem-resistant Acinetobacter baumannii infection is increasing, which might be associated with high morbidity and mortality among critically ill patients with limited therapeutic options. This study was conducted to evaluate the clinical and microbiological features of carbapenem-resistant A. baumannii bacteraemia. The medical records of 28 adult patients with this bacteraemia admitted to Korea University Guro Hospital, from January 2005 through December 2010, were reviewed. Using the 28 bloodstream isolates, we intended to detect genes encoding carbapenemases, and investigate the inoculum effect on each of the antimicrobial agents rifampicin, imipenem, colistin and tigecycline. With one blood isolate from a patient with pneumonia, rifampicin-inducible resistance was examined using the experimental mouse pneumonia model. Out of 28 carbapenem-resistant A. baumannii bloodstream infections (BIs), the most common primary focus was the central venous catheter (35.7 %) and then the lung (32.1 %). The 30 day overall mortality was 53.6 %; in most cases (80 %) the patients died within 10 days after the onset of the bacteraemia. By univariate analysis, inappropriate antimicrobial therapy (73.3 vs 30.8 %, P = 0.02), mechanical ventilation (53.3 vs 15.4 %, P = 0.04) and a high Pitt bacteraemia score (4.9±1.9 vs 2.2±1.2, P<0.01) were statistically significant risk factors for mortality, while only a high Pitt bacteraemia score (odds ratio 2.6; 95 % confidence interval 1.1-6.5) was independently associated with 30 day mortality by multivariate analysis. All 28 isolates had the bla(OXA-51)-like gene with upstream ISAbaI, 2 of which additionally had the bla(OXA-58)-like gene and the bla(OXA-23)-like gene. Inoculum effect and rifampicin inducible resistance were not detected. Considering the rapid progression to death in carbapenem-resistant A. baumannii BIs, early empirical antibiotic therapy would be warranted based on the local microbiological data in each hospital.

Acute fibrinous and organizing pneumonia in a patient with HIV infection and Pneumocystis jiroveci pneumonia

Acute fibrinous and organizing pneumonia (AFOP) is a disease of the small airways that is characterized by deposition of fibrin within the alveolar spaces. The histological pattern is described as a variant of cryptogenic organizing pneumonia (COP). Although COP has been occasionally described in patients with HIV infection, the variant form, AFOP, has not been previously reported in such patients. This report describes an intriguing case of AFOP in a patient with HIV infection and Pneumocystis jiroveci pneumonia. AFOP was diagnosed after tapering of corticosteroid therapy. This case illustrates that non‐infectious pulmonary infiltrates should be considered in the differential diagnosis of lung disease in patients with HIV infection.

Disease burden of herpes zoster in Korea

BACKGROUND The occurrence of herpes zoster can deteriorate the quality of life considerably, resulting in high disease burden. While Korea is assumed to have high disease burden of herpes zoster, there has been no researches analyzing this. OBJECTIVES We performed this study to investigate the disease burden of herpes zoster in the Korean population as a whole. STUDY DESIGN We used the database of the Health Insurance Review & Assessment Service of Korea and analyzed the data of patients who had herpes zoster as a principal diagnosis during the period from 2003 to 2007. We investigated the annual prevalence, rate of clinical visits, rate of hospitalization, and the pattern of medical services use. The socioeconomic burden of herpes zoster was calculated by a conversion into cost. RESULTS Rates of clinic visits and hospitalizations due to herpes zoster during the 5-year period from 2003 to 2007 were 7.93-12.54 per 1000 population and 0.22-0.32 per 1000 population, respectively. Prevalence rates according to age increased sharply after 50 years and reached a peak at 70 years. The total socioeconomic cost of herpes zoster was

The Clinical Usefulness of the SD Bioline Influenza Antigen Test® for Detecting the 2009 Influenza A (H1N1) Virus

75.9-143.8 million per year, increasing every year by 14-20%. CONCLUSIONS There is a heavy socioeconomic burden due to herpes zoster in Korea and indicate that appropriate policies need to be established to reduce this burden. Additional researches are also necessary to assess the safety, efficacy and cost-effectiveness of a herpes zoster vaccine in the Korean population.

Long-term and cross-reactive immunogenicity of inactivated trivalent influenza vaccine in the elderly: MF59-adjuvanted vaccine versus unadjuvanted vaccine

Though the 2009 worldwide influenza A (H1N1) pandemic has been declared to have ended, the influenza virus is expected to continue to circulate from some years as a seasonal influenza. A rapid antigen test (RAT) can aid in rapid diagnosis and allow for early antiviral treatment. We evaluated the clinical usefulness of RAT using SD Bioline Influenza Antigen Test® kit to detect the influenza virus, considering various factors. From August 1, 2009 to October 10, 2009, a total of 938 patients who visited the outpatient clinic at Korea University Guro Hospital with influenza-like illnesses were enrolled in the study. Throat or nasopharyngeal swab specimens were obtained from each of the patients. Using these specimens, we evaluated the influenza detection rate by rapid antigen test based on the real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) method. In comparison with rRT-PCR, the sensitivity and specificity of the RAT were 44.0% and 99.9%, respectively. The cyclic threshold values of RAT negative specimens were higher than RAT positive specimens (30.1±3.1 vs. 28.3±3.9, p=0.031). The sensitivity of the RAT kit was higher in patients who visited clinics within two days of symptom onset (60.4% vs. 11.1%, p=0.026). The results of this study show that the RAT cannot be recommended for general use in all patients with influenza-like illness because of its low sensitivity. The RAT may be used, only in the settings with limited diagnostic resources, for patients who visit a clinic within two days of symptom onset.