Immune Responses After Vaccination With Primary 2-Dose ChAdOx1 Plus a Booster of BNT162b2 or Vaccination With Primary 2-Dose BNT162b2 Plus a Booster of BNT162b2 and the Occurrence of Omicron Breakthrough Infection

Background@#Before the omicron era, health care workers were usually vaccinated with either the primary 2-dose ChAdOx1 nCoV-19 (Oxford-AstraZeneca) series plus a booster dose of BNT162b2 (Pfizer-BioNTech) (CCB group) or the primary 2-dose BNT162b2 series plus a booster dose of BNT162b2 (BBB group) in Korea. @*Methods@#The two groups were compared using quantification of the surrogate virus neutralization test for wild type severe acute respiratory syndrome coronavirus 2 (SVNT-WT), the omicron variant (SVNT-O), spike-specific IgG, and interferon-gamma (IFN-γ), as well as the omicron breakthrough infection cases. @*Results@#There were 113 participants enrolled in the CCB group and 51 enrolled in the BBB group. Before and after booster vaccination, the median SVNT-WT and SVNT-O values were lower in the CCB (SVNT-WT [before-after]: 72.02–97.61%, SVNT-O: 15.18–42.29%) group than in the BBB group (SVNT-WT: 89.19–98.11%, SVNT-O: 23.58–68.56%; all P < 0.001). Although the median IgG concentrations were different between the CCB and BBB groups after the primary series (2.677 vs. 4.700 AU/mL, respectively, P < 0.001), they were not different between the two groups after the booster vaccination (7.246 vs. 7.979 AU/mL, respectively, P = 0.108). In addition, the median IFN-γ concentration was higher in the BBB group than in the CCB group (550.5 and 387.5 mIU/mL, respectively, P = 0.014). There was also a difference in the cumulative incidence curves over time (CCB group 50.0% vs. BBB group 41.8%; P = 0.045), indicating that breakthrough infection occurred faster in the CCB group. @*Conclusion@#The cellular and humoral immune responses were low in the CCB group so that the breakthrough infection occurred faster in the CCB group than in the BBB group.

A study on changes in lung function, neutralizing antibodies, and symptoms of adult patients hospitalized with COVID-19

Background/Aims@#To identify changes in symptoms and pulmonary sequelae in patients with coronavirus disease 2019 (COVID-19). @*Methods@#Patients with COVID-19 hospitalized at seven university hospitals in Korea between February 2020 and February 2021 were enrolled, provided they had ≥ 1 outpatient follow-up visit. Between January 11 and March 9, 2021 (study period), residual symptom investigations, chest computed tomography (CT) scans, pulmonary function tests (PFT), and neutralizing antibody tests (NAb) were performed at the outpatient visit (cross-sectional design). Additionally, data from patients who already had follow-up outpatient visits before the study period were collected retrospectively. @*Results@#Investigation of residual symptoms, chest CT scans, PFT, and NAb were performed in 84, 35, 31, and 27 patients, respectively. After 6 months, chest discomfort and dyspnea persisted in 26.7% (4/15) and 33.3% (5/15) patients, respectively, and 40.0% (6/15) and 26.7% (4/15) patients experienced financial loss and emotional distress, respectively. When the ratio of later CT score to previous ones was calculated for each patient between three different time intervals (1–14, 15–60, and 61–365 days), the median values were 0.65 (the second interval to the first), 0.39 (the third to the second), and 0.20 (the third to the first), indicating that CT score decreases with time. In the high-severity group, the ratio was lower than in the low-severity group. @*Conclusions@#In COVID-19 survivors, chest CT score recovers over time, but recovery is slower in severely ill patients. Subjects complained of various ongoing symptoms and socioeconomic problems for several months after recovery.

Clinical Practice Guidelines for Fecal Microbiota Transplantation in Korea

Fecal microbiota transplantation (FMT) is a highly efficacious and safe modality for the treatment of recurrent or refractory Clostridioides difficile infection (CDI), with overall success rates of 90%. Thus, FMT has been widely used for 10 years. The incidence and clinical characteristics of CDI, the main indication for FMT, differ between countries. To date, several guidelines have been published. However, most of them were published in Western countries and therefore cannot represent the Korean national healthcare systems. One of the barriers to performing FMT is a lack of national guidelines. Accordingly, multidisciplinary experts in this field have developed practical guidelines for FMT. The purpose of these guidelines is to aid physicians performing FMT, which can be adapted to treat CDI and other conditions.

Rhinovirus Incidence Rates Indicate We Are Tired of Non-pharmacological Interventions Against Coronavirus Disease 2019

Background@#During the coronavirus disease 2019 (COVID-19) pandemic, the incidence of rhinovirus (RV) is inversely related to the intensity of non-pharmacological interventions (NPIs), such as universal mask wearing and physical distancing. @*Methods@#Using RV surveillance data, changes in the effect of NPIs were investigated in South Korea during the pandemic. The time to the first visible effect of NPIs after the onset of NPIs (T1), time to the maximum effect (T2), and duration of the maximum effect (T3) were measured for each surge. For each week, the RVdiff [(RV incidence during the pandemic) − (RV incidence within 5 years before the pandemic)] was calculated, and number of weeks for RVdiff to be below zero after NPIs (time to RVdiff ≤ 0) and number of weeks RVdiff remains below zero after NPIs (duration of RVdiff ≤ 0) were measured for each surge. @*Results@#During the study period, four surges of COVID-19 were reported. As the pandemic progressed, T1 and T2 increased, but T3 decreased. Additionally, the “time to RVdiff of ≤ 0” increased and “duration of RVdiff of ≤ 0” decreased. These changes became more pronounced during the third surge (mid-November 2020), before the introduction of the COVID-19 vaccine, and from the emergence of the delta variant. @*Conclusion@#The effect of NPIs appears slower, the duration of the effect becomes shorter, and the intensity also decreases less than a year after the onset of the pandemic owing to people’s exhaustion in implementing NPIs. These findings suggest that the COVID-19 response strategy must be completely overhauled

Hip Fracture Management during the COVID-19 Pandemic in South Korea

Background@#The purpose of this study was to introduce a screening system for coronavirus disease 2019 (COVID-19), to evaluate the overall orthopedic management in hip fracture patients during the COVID-19 pandemic in South Korea, and to compare the surgical results in hip fracture patients during the COVID-19 pandemic with those of the previous year. @*Methods@#Hip fracture patients who visited emergency rooms were screened at the screening clinics before admission. The medical management was carried out with the medical staff wearing surgical masks, meticulous hand hygiene observed, and a minimum distance of 2 m between patients maintained. The demographics, operative parameters, and surgical results of patients treated during the pandemic were compared with those from the previous year. @*Results@#From January 2020 to July 21, 2020, 119 patients with hip fractures (33 men and 86 women) were admitted to our institution for surgical treatment. Five patients showed symptoms of pneumonia, but no patient was positive for COVID-19. The mortality rate during the study period was 4.2%, and none of the patients died due to COVID-19. The interval between admission and surgery and the length of hospital stay were significantly shorter (p = 0.008, p = 0.002) and the proportion of spinal anesthesia was greater in hip fracture patients during the COVID-19 pandemic compared to those from the previous year (p = 0.011). @*Conclusions@#The COVID-19 screening system for hip fracture patients has proven to be effective in preventing intrahospital spread of the disease. Hip fracture surgery performed during the COVID-19 pandemic has shown comparable results without any COVID-19 infection and COVID-19-related mortality.

Clinical and Virologic Effectiveness of Remdesivir Treatment for Severe Coronavirus Disease 2019 (COVID-19) in Korea: a Nationwide Multicenter Retrospective Cohort Study

Background@#Remdesivir is widely used for the treatment of coronavirus disease 2019 (COVID-19), but controversies regarding its efficacy still remain. @*Methods@#A retrospective cohort study was conducted to evaluate the effect of remdesivir on clinical and virologic outcomes of severe COVID-19 patients from June to July 2020. Primary clinical endpoints included clinical recovery, additional mechanical ventilator (MV) support, and duration of oxygen or MV support. Viral load reduction by hospital day (HD) 15 was evaluated by calculating changes in cycle threshold (Ct) values. @*Results@#A total of 86 severe COVID-19 patients were evaluated including 48 remdesivirtreated patients. Baseline characteristics were not significantly different between the two groups. Remdesivir was administered an average of 7.42 days from symptom onset. The proportions of clinical recovery of the remdesivir and supportive care group at HD 14 (56.3% and 39.5%) and HD 28 (87.5% and 78.9%) were not statistically different. The proportion of patients requiring MV support by HD 28 was significantly lower in the remdesivir group than in the supportive care group (22.9% vs. 44.7%, P = 0.032), and MV duration was significantly shorter in the remdesivir group (average, 1.97 vs. 5.37 days; P = 0.017). Analysis of upper respiratory tract specimens demonstrated that increases of Ct value from HD 1–5 to 11–15 were significantly greater in the remdesivir group than the supportive care group (average, 10.19 vs. 5.36; P = 0.007), and the slope of the Ct value increase was also significantly steeper in the remdesivir group (average, 5.10 vs. 2.68; P = 0.007). @*Conclusion@#The remdesivir group showed clinical and virologic benefit in terms of MV requirement and viral load reduction, supporting remdesivir treatment for severe COVID-19.

Clinical and Virologic Effectiveness of Remdesivir Treatment for Severe Coronavirus Disease 2019 (COVID-19) in Korea: a Nationwide Multicenter Retrospective Cohort Study

Background@#Remdesivir is widely used for the treatment of coronavirus disease 2019 (COVID-19), but controversies regarding its efficacy still remain. @*Methods@#A retrospective cohort study was conducted to evaluate the effect of remdesivir on clinical and virologic outcomes of severe COVID-19 patients from June to July 2020. Primary clinical endpoints included clinical recovery, additional mechanical ventilator (MV) support, and duration of oxygen or MV support. Viral load reduction by hospital day (HD) 15 was evaluated by calculating changes in cycle threshold (Ct) values. @*Results@#A total of 86 severe COVID-19 patients were evaluated including 48 remdesivirtreated patients. Baseline characteristics were not significantly different between the two groups. Remdesivir was administered an average of 7.42 days from symptom onset. The proportions of clinical recovery of the remdesivir and supportive care group at HD 14 (56.3% and 39.5%) and HD 28 (87.5% and 78.9%) were not statistically different. The proportion of patients requiring MV support by HD 28 was significantly lower in the remdesivir group than in the supportive care group (22.9% vs. 44.7%, P = 0.032), and MV duration was significantly shorter in the remdesivir group (average, 1.97 vs. 5.37 days; P = 0.017). Analysis of upper respiratory tract specimens demonstrated that increases of Ct value from HD 1–5 to 11–15 were significantly greater in the remdesivir group than the supportive care group (average, 10.19 vs. 5.36; P = 0.007), and the slope of the Ct value increase was also significantly steeper in the remdesivir group (average, 5.10 vs. 2.68; P = 0.007). @*Conclusion@#The remdesivir group showed clinical and virologic benefit in terms of MV requirement and viral load reduction, supporting remdesivir treatment for severe COVID-19.

Clinical Pathway for Emergency Brain Surgery during COVID-19 Pandemic and Its Impact on Clinical Outcomes

Background@#One of the challenges neurosurgeons are facing in the global public health crisis caused by the coronavirus disease 2019 (COVID-19) pandemic is to balance COVID-19 screening with timely surgery. We described a clinical pathway for patients who needed emergency brain surgery and determined whether differences in the surgery preparation process caused by COVID-19 screening affected clinical outcomes. @*Methods@#During the COVID-19 period, patients in need of emergency brain surgery in our institution were managed using a novel standardized pathway designed for COVID-19 screening. We conducted a retrospective review of patients who were hospitalized through the emergency room and underwent emergency brain surgery. A total of 32 patients who underwent emergency brain surgery from February 1 to June 30, 2020 were included in the COVID-19 group, and 65 patients who underwent surgery from February 1 to June 30, 2019 were included in the pre-COVID-19 group. The baseline characteristics, disease severity indicators, time intervals of emergency processes, and clinical outcomes of the two groups were compared. Subgroup analysis was performed between the immediate surgery group and the semi-elective surgery group during the COVID-19 period. @*Results@#There were no significant differences in baseline characteristics and severity indicators between the pre-COVID-19 group and COVID-19 group. The time interval to skin incision was significantly increased in the COVID-19 group (P = 0.027). However, there were no significant differences in the clinical outcomes between the two groups. In subgroup comparison, the time interval to skin incision was shorter in the immediate surgery group during the COVID-19 period compared with the pre-COVID-19 group (P = 0.040). The screening process did not significantly increase the time interval to classification and admission for immediate surgery.The time interval to surgery initiation was longer in the COVID-19 period due to the increased time interval in the semi-elective surgery group (P < 0.001). @*Conclusion@#We proposed a clinical pathway for the preoperative screening of COVID-19 in patients requiring emergency brain surgery. No significant differences were observed in the clinical outcomes before and after the COVID-19 pandemic. The protocol we described showed acceptable results during this pandemic.

Ten-Year Prevalence Trends of Phenotypically Identified Community-Associated Methicillin-Resistant Staphylococcus aureus Strains in Clinical Specimens

Background@#Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains were first detected in hospitals in Korea between the late 2000s and early 2010s.However, there is limited information regarding the prevalence of CA-MRSA strains among hospital isolates and their phenotypic changes over the last decade. We investigated the prevalence trend of CA-MRSA strains isolated from different clinical specimens and their phenotypic changes between September 2009 and September 2019. @*Methods@#CA-MRSA strains were phenotypically identified by confirming their resistance to penicillin (PCN) and oxacillin (OXA) and evaluating their susceptibility to trimethoprimsulfamethoxazole, rifampin, fusidic acid, tetracycline, and at least one of the following four antimicrobials: clindamycin (CLI), erythromycin (ERY), ciprofloxacin (CIP), and gentamicin (GEN). A CA-MRSA strain that exhibited resistance to ERY, CLI, CIP, or GEN was classified as having resistance pattern I, II, III, or IV, respectively, regardless of its resistance to other antimicrobial agents. @*Results@#Of the 8,278 MRSA isolates identified in specimens obtained two days after admission, 1,385 (16.73%) were CA-MRSA strains. The prevalence of CA-MRSA strains increased from 12.2% to 26.6% (3.21% per period, P = 0.05). Resistance type analysis revealed an increasing trend in the prevalence of PCN/OXA-resistant (1.84%; P = 0.049) and PCN/OXA/ERY/CLI/CIP-resistant (0.98%; P = 0.04) CA-MRSA strains and in resistance pattern III strains (2.08%; P = 0.004). @*Conclusions@#The prevalence of CA-MRSA strains in Korea has increased significantly over the last decade, and CA-MRSA strains have gained phenotypic diversity beyond PCN/OXAresistance, including antimicrobial resistance to non-β-lactams, especially CIP.

Clinical Characteristics of COVID-19: Clinical Dynamics of Mild Severe Acute Respiratory Syndrome Coronavirus 2 Infection Detected by Early Active Surveillance

Background@#There is limited information describing the presenting characteristics and dynamic clinical changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnosed in the early phase of illness. This study is a case series of patients with coronavirus disease 2019 (COVID-19) admitted to 11 hospitals in Korea. @*Methods@#Patients with confirmed SARS-CoV-2 infection by positive polymerase chain reaction (PCR) testing of respiratory specimens by active surveillance that were finally discharged between February 20 and April 30, 2020 were included. Patients were classified into mild and non-mild groups on initial admission according to oxygen demand and Sequential Organ Failure Assessment score, and the mild group was followed up and subgrouped into non-aggravation and aggravation groups. @*Results@#A total of 161 patients with SARS-CoV2 infection were enrolled. Among the mild group of 136 patients, 11.7% of patients experienced clinical aggravation during hospitalization, but there was no initial clinical parameter on admission predicting their aggravation. Fever (odds ratio [OR], 4.56), thrombocytopenia (OR, 12.87), fever (OR, 27.22) and lactate dehydrogenase (LDH) > 300 U/L (OR, 18.35), and CRP > 1 mg/dL (OR, 11.31) significantly indicated aggravation in the 1st, 2nd, 3rd, and 4th 5-day periods, respectively.PCR positivity lasted for a median of 22 days and 32 days after the onset of illness in the nonaggravation and aggravation groups, respectively. @*Conclusion@#Old age was associated with early severe presentation. Clinical aggravation among asymptomatic or mild patients could not be predicted initially but was heralded by fever and several laboratory markers during the clinical course.

Antibiotic Treatment of Vertebral Osteomyelitis caused by Methicillin-Susceptible Staphylococcus aureus: A Focus on the Use of Oral β-lactams

BACKGROUND@#Vertebral osteomyelitis (VO) is a rare but serious condition, and a potentially significant cause of morbidity. Methicillin-susceptible Staphylococcus aureus (MSSA) is the most common microorganism in native VO. Long-term administration of parenteral and oral antibiotics with good bioavailability and bone penetration is required for therapy. Use of oral β-lactams against staphylococcal bone and joint infections in adults is not generally recommended, but some experts recommend oral switching with β-lactams. This study aimed to describe the current status of antibiotic therapy and treatment outcomes of oral switching with β-lactams in patients with MSSA VO, and to assess risk factors for treatment failure.@*MATERIALS AND METHODS@#This retrospective study included adult patients with MSSA VO treated at nine university hospitals in Korea between 2005 and 2014. Treatment failure was defined as infection-related death, microbiological relapse, neurologic deficits, or unplanned surgical procedures. Clinical characteristics and antibiotic therapy in the treatment success and treatment failure groups were compared. Risk factors for treatment failure were identified using the Cox proportional hazards model.@*RESULTS@#A total of 100 patients with MSSA VO were included. All patients were treated, initially or during antibiotic therapy, with one or more parenteral antibiotics. Sixty-nine patients received one or more oral antibiotics. Antibiotic regimens were diverse and durations of parenteral and oral therapy differed, depending on the patient and the hospital. Forty-two patients were treated with parenteral and/or oral β-lactams for a total duration of more than 2 weeks. Compared with patients receiving parenteral β-lactams only, no significant difference in success rates was observed in patients who received oral β-lactams for a relatively long period. Sixteen patients had treatment failure. Old age (adjusted hazard ratio [HR] 5.600, 95% confidence interval [CI] 1.402 – 22.372, P = 0.015) and failure to improve C-reactive protein levels at follow-up (adjusted HR 3.388, 95% CI 1.168 – 9.829, P = 0.025) were independent risk factors for treatment failure.@*CONCLUSION@#In the study hospitals, diverse combinations of antibiotics and differing durations of parenteral and oral therapy were used. Based on the findings of this study, we think that switching to oral β-lactams may be safe in certain adult patients with MSSA VO. Since limited data are available on the efficacy of oral antibiotics for treatment of staphylococcal VO in adults, further evaluation of the role of oral switch therapy with β-lactams is needed.

Safety and Effectiveness of Peramivir in Korean Adult Influenza Patients: Prospective Observational Study Based on Post-Marketing Surveillance Data

BACKGROUND: The safety and clinical effectiveness data of peramivir in the real clinical field are limited. A prospective observational study was conducted based on the post-marketing surveillance data to evaluate the post-marketing safety and effectiveness of peramivir in Korean adults with seasonal influenza. METHODS: Among adults aged 20 years or older who were diagnosed with influenza A or B, patients who started peramivir within 48 hours from the initial symptoms of influenza were enrolled. All adverse events (AEs) that occurred within 7 days after administration of peramivir were checked. For the evaluation of effectiveness, changes in the severity of influenza symptoms and daily living performance were examined before and 7 days after the administration of peramivir. The date on which influenza related symptoms disappeared was checked. RESULTS: A total of 3,024 patients were enrolled for safety evaluation and 2,939 patients were for effectiveness evaluation. In the safety evaluation, 42 AEs were observed in 35 (1.16%) patients. The most common AE was fever. AEs were mostly rated as mild in severity. Serious AEs were observed in 10 patients and two of them died. However, both deaths were considered to be less relevant to peramivir. In the effectiveness evaluation, the severity of influenza symptoms decreased by 10.68 ± 4.01 points and daily living performance was improved 5.59 ± 2.16 points. Influenza related symptoms disappeared on average 3.02 ± 2.39 days after peramivir administration. CONCLUSION: Peramivir showed a tolerable safety profile and acceptable effectiveness in Korean adult patients with seasonal influenza.

Late diagnosis of influenza in adult patients during a seasonal outbreak

BACKGROUND/AIMS: Due to advances in diagnostic techniques, clinicians are more frequently performing influenza diagnostic tests and referring to their test results ahead of the administration of neuraminidase inhibitors (NAIs). To investigate the clinical significance of the time from symptom onset to laboratory diagnosis, we reviewed the clinical characteristics of adult patients with influenza who had an early laboratory diagnosis (ED) or a late laboratory diagnosis (LD) at one of four tertiary care centers during a seasonal outbreak of influenza. METHODS: Clinical data were collected from 1,405 adults during the 2013 to 2014 influenza season. A patient was regarded as receiving an ED or LD if he/she received an influenza diagnostic test at 0 to 1 or 4 to 7 days after symptom onset, respectively. Early NAI therapy and late NAI therapy were defined as the administration of NAI ≤ 2 or > 2 days after symptom onset, respectively. RESULTS: Nearly half of the patients (47.0%) received an ED (n = 661), whereas 13.5% (n = 190) received a LD. Patients with a LD had initial symptoms of cough, sputum production, and dyspnea and experienced pneumonia, antibiotic therapy, hospitalization, and admission to the intensive care unit more often than those with an ED. NAI therapy and early NAI therapy were less frequent in patients with a LD than those with an ED. Of the analyzed baseline characteristics, age ≥ 50 years, influenza B infection, and diagnosis using a polymerase chain reaction test were significantly associated with a LD. CONCLUSIONS: LD was associated with inappropriate antiviral therapy and complicated presenting features in adult patients with seasonal influenza. ED of influenza should be emphasized, especially for older adults.

Outpatient treatment in women with acute pyelonephritis after visiting emergency department

No abstract available.

In vitro Antibacterial Activity of Doripenem against Gram-Negative Blood Isolates in a Korean Tertiary Care Center

BACKGROUND: Doripenem is the most recently introduced antimicrobial agent of the carbapenem class. It is a valuable therapeutic option in the context of increasing antimicrobial resistance to imipenem and meropenem among gram-negative bacilli (GNB) clinical isolates. However, clinicians are usually reluctant to prescribe doripenem, because susceptibility to doripenem is not automatically reported by most clinical laboratories and the in vitro activity of doripenem against clinically significant GNB isolates remains uncertain. MATERIALS AND METHODS: We investigated the in vitro antibacterial activity of doripenem in GNB blood isolates in a tertiary care center. Over a period of 10 months, 212 adult bacteremia cases were treated at the study hospital. Doripenem susceptibility testing was performed for the 212 blood isolates by the disk diffusion method, and clinical data were collected. RESULTS: Among the blood isolates, the rate of doripenem resistance (7.5%) was lower than that of imipenem (12.9%) or other anti-GNB antimicrobial agents, except amikacin (2.1%). Almost all imipenem-susceptible GNB blood isolates (181/182, 99.5%) were susceptible to doripenem. Whereas doripenem resistance was rarely observed in Enterobacteriaceae (2/181, 1.1%), it was frequently observed in patients with non-fermentatative GNB (12/27, 44.4%), hospital-acquired infections (7/27, 25.9%), and pneumonia (11/49, 22.4%). CONCLUSION: Doripenem exhibited more potent in vitro activity against GNB blood isolates than other anti-GNB antimicrobial agents in a tertiary care center where it was infrequently prescribed compared with other carbapenems. However, its clinical utility may be limited due to the increasing number of carbapenem-resistant non-fermentative GNB infections.

Utilization of the respiratory virus multiplex reverse transcription-polymerase chain reaction test for adult patients at a Korean tertiary care center

BACKGROUND/AIMS: Respiratory viruses (RVs) are considered to be important respiratory pathogens in adult patients, and the multiplex reverse transcription-polymerase chain reaction (RT-PCR) test is used frequently in adult patients with respiratory infections. However, clinical data regarding utilization of the multiplex RT-PCR test for RVs are lacking. METHODS: We investigated the utilization of the multiplex RT-PCR test for RVs at Chung-Ang University Hospital in Seoul, Korea, between January 2012 and April 2013. RESULTS: During the study period, the multiplex RT-PCR test was performed for 291 adult patients. The test frequency was 4.9% of rapid influenza antigen detection tests and 0.8% of respiratory bacterial culture studies. A turnaround time of < 48 hours was observed in 25.9% of positive tests. Most of the tests were performed for admitted patients (97.9%) with a community-acquired infection (84.2%) during the flu season (82.5%). RVs were detected in 81 of 291 cases (27.8%). The RV positivity rates for community- and hospital-acquired infections did not differ (28.6% vs. 23.9%, p = 0.52). Of 166 patients with pneumonia, 44 (26.5%) had a viral infection. Among the patients with RV-associated pneumonia, an RV other than influenza was detected in 20 patients (45.4%). CONCLUSIONS: The multiplex RT-PCR test for RVs was infrequently performed at a tertiary care center, and the test results were often reported late. The test was most often performed for admitted adult patients with community-acquired infections during the flu season. The utilization of multiplex RT-PCR testing for RVs in current clinical practice should be improved.

Prevalence and impact of extended-spectrum beta-lactamase production on clinical outcomes in cancer patients with Enterobacter species bacteremia

BACKGROUND/AIMS: We examined the prevalence of extended-spectrum beta-lactamase (ESBL) production and the impact of ESBL on clinical outcomes in cancer patients with Enterobacter spp. bacteremia. METHODS: Using prospective cohort data on Enterobacter bacteremia obtained between January 2005 and November 2008 from a tertiary care center, the prevalence and clinical impact of ESBL production were evaluated. RESULTS: Two-hundred and three episodes of Enterobacter spp. bacteremia were identified. Thirty-one blood isolates (15.3%, 31/203) scored positive by the double-disk synergy test. Among 17 isolates in which ESBL genes were detected by polymerase chain reaction and sequencing, CTX-M (n = 12), SHV-12 (n = 11), and TEM (n = 4) were the most prevalent ESBL types. Prior usage of antimicrobial agents (77.4% vs. 54.0%, p = 0.02) and inappropriate empirical antimicrobial therapy (22.6% vs. 3.0%, p < 0.001) were more commonly encountered in the ESBL-positive group than in the extended-spectrum cephalosporin-susceptible ESBL-negative group, respectively. Clinical outcomes did not differ significantly between the two groups (30-day mortality rate, 19.4% vs. 17.0%, p = 0.76; median length of hospital stay, 24.0 days vs. 30.5 days, p = 0.97). Initial presentation of severe sepsis/septic shock, pneumonia, and intra-abdominal infection were independently associated with 30-day mortality. CONCLUSIONS: The prevalence of ESBL-producing isolates was 15.3% in cancer patients with Enterobacter bacteremia. Although inappropriate empirical therapy was more common in the ESBL-positive group, ESBL production was not associated with poorer outcomes.

Clinical Characteristics and Causative Organisms of Community-acquired Necrotizing Fasciitis

BACKGROUND: Necrotizing fasciitis (NF) is an infrequent but potentially lethal infection characterized by rapid progressive destruction of fascia and fat, concomitant systemic toxicity, and high fatality. In spite of the clinical significance of NF, only limited data is available regarding the clinical characteristics of patients with NF in Korea. MATERIALS AND METHODS: We retrospectively reviewed the medical records of patients who had been diagnosed as community-acquired NF in 9 centers of the Republic of Korea between January 2000 and November 2010. RESULTS: During the study period, a total of 103 patients had a community-acquired NF. Of sixty six cases with causative microorganisms identified, the majority (55, 83.3%) had monomicrobial infections. Whereas streptococci were the most common cause of NF in patients without underlying diseases (16/24, 66.7%), variable organisms, such as staphylococci, streptococci, Enterobacteriaceae, and non-fermentative Gram-negative bacilli were causative organisms of NF in patients with underlying diseases. The majority of patients with NF caused by Vibrio vulnificus or Aeromonas hydrophila (7/9, 77.8%) had liver cirrhosis or alcoholism. Surgery to counteract NF was performed in 60.2% of patients with NF (62/102), and mean time to surgery was 3 days. In-hospital mortality was observed in 21 of 99 patients with available data (21.2%). In multivariate analysis, the presence of solid tumors (adjusted OR [aOR]=63.88, 95% CI=2.58-1580.61, P=0.011), shock (aOR= 24.19, 95% CI=2.00-292.19, P=0.012), bacteremia (aOR=87.53, 95% CI=3.99-1921.46, P=0.005), and Gram-negative bacilli infections (aOR=437.11, 95% CI=4.67-40956.82, P=0.009) were associated with in-hospital mortality. CONCLUSIONS: Streptococci were predominant causative organisms of community-acquired NF in patients without underlying diseases. However, in patients with underlying diseases, variable organisms such as staphylococci, streptococci, Enterobacteriaceae, or non-fermentative Gram-negative bacilli were isolated. NF caused by V. vulnificus or A. hydrophila occurred frequently in patients with liver cirrhosis or alcoholism.

Epidemiology and Clinical outcomes of Invasive Pulmonary Aspergillosis: A Nationwide Multicenter Study in Korea

BACKGROUND: Invasive pulmonary aspergillosis (IPA) is an important cause of morbidity and mortality in immunocompromised patients. However, few data on clinical characteristics and outcomes of IPA in Korea have been reported. We conducted a nationwide multicenter study in Korea for evaluation of the epidemiology and clinical outcomes of invasive pulmonary aspergillosis. MATERIALS AND METHODS: A retrospective cohort study was conducted in 10 hospitals in Korea. We reviewed all adult patients who met the revised EORTC/MSG definitions between 2008 and 2010. RESULTS: A total of 334 cases, which included proven (26, 8%), probable (159, 48%), or possible (149, 44%) IPA, were identified. Patients with proven or probable IPA were evaluated, and, of these 185 IPA patients, 105 (57%) had neutropenia, 30 (16%) underwent hematopoietic stem cell transplantation, 25 (14%) underwent solid organ transplantation, and 32 (17%) without neutropenia and transplantation received immunosuppressive agents or corticosteroid. Aspergillus spp. were isolated from 42 patients (23%), and positive fungal culture rates from sterile fluid, sputum, and bronchoalveolar lavage fluid (BAL) were 67% (6/9), 21% (32/150), and 20% (9/44), respectively. Results of assays for sensitivity of serum and BAL galactomannan were 84% (155/184) and 89% (25/28), respectively. Amphotericin-B deoxycholate and itraconazole were most commonly administered as a primary therapy in 107 (58%) and 34 (19%) patients, respectively. Of 133 patients (73%) who received salvage therapy after primary antifungal therapy for a median period of six days (IQR 3-12), 82 (62%) patients were treated with voriconazole. Of 185 patients, 82 (44%) died within three months after diagnosis of IPA. CT findings, including small airway lesions and micronodules, ground glass opacities, and pleural effusion and persistent positive galactomannan status showed an independent association with worse outcome, while proven diagnosis of IPA showed an independent association with better outcome. CONCLUSIONS: Microbiologic confirmation of IPA was low in Korea; therefore, many Korean physicians were dependent on the galactomannan assay for microbiologic diagnosis. Primary therapy with Amphotericin-B deoxycholate followed by salvage therapy with voriconazole was the most common antifungal strategy for treatment of patients with IPA in Korea. Overall mortality and IPA-related mortality were comparable with data from Western clinical trials.

Clinical Characteristics and Organisms Causing Erysipelas and Cellulitis

BACKGROUND: Although erysipelas and cellulitis are common soft tissue infectious diseases, there have been a few studies which investigate clinical characteristics and causative organisms in Korea. MATERIALS AND METHODS: We retrospectively reviewed the medical records of patients who had been diagnosed with erysipelas or cellulitis from ten general hospitals between January 2009 and February 2011. RESULTS: During the study period, a total of 144 patients with erysipelas and 735 with cellulitis were recruited. The mean age of erysipelas patients was 53.6 years, and that of cellulitis patients was 47.5 years. Diabetes mellitus was the most common underlying disease in both groups. The most common site of erysipelas was the face (80.6%) and that of cellulitis was the lower extremity (64.9%). Culture studies have been done in 31.9% (46/144) of patients with erysipelas, and 41.1% (302/735) with cellulites. Causative organisms were identified in 3 patients (2.1%) with erysipelas and 57 (7.8%) with cellulitis. Streptococcus pyogenes was isolated from two patients with erysipelas, and group G streptococcus from one. Staphylococcus aureus (44.0%) was the most common isolate in patients with cellulitis, followed by streptococci (27.1%), Enteobateriaceae (11.9%), and Vibrio species (6.8%). First-generation cephalosporin was the most commonly used antimicrobial agent in both groups. CONCLUSIONS: beta-hemolytic streptococcus and S. aureus were the most common causative organisms of patients with erysipelas and cellulitis.