Which is the Preferred Regimen for Non-Severe Clostridioides difficile Infection in Korea, Vancomycin or Metronidazole? / 감염과화학요법

The emergence of hypervirulent Clostridioides difficile strains has decreased the efficacy of metronidazole in the treatment of C. difficile infection (CDI). Therefore, revised guidelines no longer recommend the use of metronidazole as a first-line regimen for CDI and restrict its use for non-severe CDI, only when vancomycin and fidaxomicin are unavailable. In Korea, an epidemic caused by a hypervirulent C. difficile strain or the emergence of metronidazole resistant C. difficile strains have not been reported. This review article aims to compare the treatment outcomes and adverse effects of vancomycin and metronidazole and discuss the validity of the guidelines of various agencies, which restrict the use of metronidazole, for Korean patients. There are no substantial adverse effects of metronidazole, and its clinical outcomes against non-severe CDI are similar to those of vancomycin. Based on these findings, we recommend that the use of metronidazole for the treatment of non-severe CDI is still an appropriate option in Korea.

Quantitative Evaluation of the Economic Impact of Antimicrobial Resistance on the Treatment of Community-Acquired Acute Pyelonephritis in Korea / 감염과화학요법

Background@#The proportion of antimicrobial-resistant Enterobacteriales as a causative pathogen of community-acquired acute pyelonephritis (APN) has been increasing. The aim of this study was to quantitatively evaluate the impact of antimicrobial resistance on medical costs and length of hospital stay for the treatment of APN. @*Materials and Methods@#A single-center retrospective cohort study was conducted between January 2018 and December 2019. All hospitalized patients aged ≥19 years who were diagnosed with community-acquired APN were recruited, and those diagnosed with Enterobacteriales as a causative pathogen were included. Log-linear regression analysis was performed to determine the risk factors for medical costs and length of hospital stay. @*Results@#A total of 241 patients participated in this study. Of these, 75 (31.1%) and 87 (36.1%) had extended-spectrum beta-lactamase (ESBL)-producing pathogens and ciprofloxacinresistant pathogens as the causative pathogen, respectively. Based on the log-linear regression model, ESBL-producing Enterobacteriales is a causative pathogen that is, on average, 27.0%, or United States Dollar (USD) 1,211 (P = 0.026) more expensive than non-ESBL-producing Enterobacteriales. A patient who is a year older would incur USD 23 (P = 0.040) more, those having any structural problems in the urinary tract would incur USD 1,231 (P = 0.015) more, and those with a unit increase in the Pitt bacteremia score would incur USD 767 (P <0.001) more, with all other variables constant. Having a case in which ESBL-producing Enterobacteriales is a causative pathogen would explain staying 22.0% longer or 2 more days (P = 0.050) in the hospital than non-ESBL-producing Enterobacteriales. A patient who is 10 years older would, on average, would have to stay for half a day longer (P = 0.045). Any structural problems in the urinary tract explain a longer stay (2.4 days longer; P = 0.032), and moving from 0 to 5 on the Pitt bacteremia score would explain four more days (P = 0.038) in the hospital. @*Conclusion@#Patients with community-acquired APN with ESBL-producing Enterobacteriales as the causative pathogen would incur, on average, 27.0% higher medical costs and 22.0% longer hospitalization days than patients detected with non-ESBL-producing pathogens.

Clinical Characteristics of Patients with Adrenal Insufficiency and Fever

Background@#Because persistent fever often occurs in adrenal insufficiency, it might be confused with infectious diseases. This study aimed to identify clinical characteristics and risk factors of patients with adrenal insufficiency and fever. @*Methods@#All adult patients (n = 150) admitted to a tertiary care hospital in South Korea and diagnosed with adrenal insufficiency between 1 March 2018, and 30 June 2019, were recruited. Patients were excluded if they had: 1) proven structural problems in the adrenal or pituitary gland; 2) a history of chemotherapy within 6 months prior to the diagnosis of adrenal insufficiency; and 3) other medical conditions that may cause fever. @*Results@#Among the included patients, 45 (30.0%) had fever at the time of the diagnosis of adrenal insufficiency. The mean C-reactive protein level was higher (11.25 ± 8.54 vs. 4.36 ± 7.13 mg/dL) in patients with fever than in those without fever. A higher proportion of patients with fever changed antibiotics (33.3% vs. 1.0%). On multivariate logistic regression analysis, female sex (odds ratio [OR], 0.32) lowered the risk of adrenal insufficiency with fever, while a history of surgery within 6 months (OR, 4.35), general weakness (OR, 7.21), and cough (OR, 17.29) were significantly associated with that. @*Conclusion@#The possibility of adrenal insufficiency should be considered in patients with fever of unknown origin, especially those with risk factors.

A Case of Human Immunodeficiency Virus -triggered Hemophagocytic Lymphohistocytosis Presenting with Severe Bleeding Tendency / 감염과화학요법

Human immunodeficiency virus (HIV) is one of the less common triggers of secondary hemophagocytic lymphohistiocytosis (HLH) in which coagulation disorder is a frequent manifestation. Here, we present a case of HIV-triggered secondary HLH presenting with severe bleeding tendency and fever. Despite high-dose dexamethasone infusion (10 mg/body surface area/day), progressive disseminated intravascular coagulation and thrombocytopenia resulted in massive hemathochezia: the bleeding episode ceased after endoscopic hemoclipping. After then, he took a highly-active antiretroviral therapy (HAART). Eventually, body temperature and overall laboratory findings normalized in response to HAART.Clinicians should not overlook HIV infection as a possible trigger of secondary HLH. In such cases, HAART is the core treatment.

Clinical Characteristics of Patients with Adrenal Insufficiency and Fever

Background@#Because persistent fever often occurs in adrenal insufficiency, it might be confused with infectious diseases. This study aimed to identify clinical characteristics and risk factors of patients with adrenal insufficiency and fever. @*Methods@#All adult patients (n = 150) admitted to a tertiary care hospital in South Korea and diagnosed with adrenal insufficiency between 1 March 2018, and 30 June 2019, were recruited. Patients were excluded if they had: 1) proven structural problems in the adrenal or pituitary gland; 2) a history of chemotherapy within 6 months prior to the diagnosis of adrenal insufficiency; and 3) other medical conditions that may cause fever. @*Results@#Among the included patients, 45 (30.0%) had fever at the time of the diagnosis of adrenal insufficiency. The mean C-reactive protein level was higher (11.25 ± 8.54 vs. 4.36 ± 7.13 mg/dL) in patients with fever than in those without fever. A higher proportion of patients with fever changed antibiotics (33.3% vs. 1.0%). On multivariate logistic regression analysis, female sex (odds ratio [OR], 0.32) lowered the risk of adrenal insufficiency with fever, while a history of surgery within 6 months (OR, 4.35), general weakness (OR, 7.21), and cough (OR, 17.29) were significantly associated with that. @*Conclusion@#The possibility of adrenal insufficiency should be considered in patients with fever of unknown origin, especially those with risk factors.

Trend of Antibiotic Usage for Hospitalized Community-acquired Pneumonia Cases in Korea Based on the 2010–2015 National Health Insurance Data

Background@#This study is to describe the changes in prescribing practices of antibiotics to treat community-acquired pneumonia (CAP) in Korea during 2010–2015. @*Methods@#The claim database of the Health Insurance Review and Assessment Service in Korea was used to select adult patients (≥ 18 years of age) admitted between 2010 and 2015, with the International Classification of Diseases, Tenth Revision codes relevant to all-cause pneumonia for the first or second priority discharge diagnosis. The episodes with hospital-acquired or healthcare-associated pneumonia were excluded. Consumption of each antibiotic was converted to defined daily dose (DDD) per episode. The amount of antibiotic consumption was compared between patients with CAP aged < 65 years and those aged ≥ 65 years. @*Results@#The average amount of antibiotic consumption per episode was 15.5 DDD, which remained stable throughout the study period (P = 0.635). Patients aged ≥ 65 years received more antibiotics than those aged < 65 years (15.7 vs. 15.3 DDD). Third-generation cephalosporin (4.9 DDD/episode, 31.4%) was the most commonly prescribed, followed by macrolide (2.7 DDD/episode, 17.1%) and beta-lactam/beta-lactamase inhibitor (BL/BLI) (2.1 DDD/episode, 13.6%). The consumption amount of fourth-generation cephalosporin (4th CEP) (P = 0.001), BL/BLI (P = 0.003) and carbapenem (P = 0.002) increased each year during the study period. The consumption of 4th CEP and carbapenem was doubled during 2010–2015. @*Conclusion@#The prescription of broad-spectrum antibiotics such as 4th CEP and carbapenem to treat CAP increased in Korea during 2010–2015.

Association between Antibiotic Consumption and Incidence of Clostridioides difficile Infection in a Hospital

Previous exposure to antimicrobials is a major risk factor for Clostridioides difficile infection (CDI). Antibiotic prescription and C. difficile toxin assay records of patients admitted to a tertiary hospital in Korea from 2009 to 2013 were collected to investigate the association between antibiotic consumption and CDI incidence. A Spearman's correlation analysis between CDI incidence (positive result of toxin assay/10,000 admissions) and antibiotic consumption (defined daily dose/1,000 patient-days) was performed on a monthly basis. Using the matched month approach, we found a significant correlation between CDI rate and moxifloxacin consumption (Spearman's r = 0.351, P < 0.001). Furthermore, using the onemonth delay approach, we found that the consumption of clindamycin (Spearman's r = 0.272, P = 0.037) and moxifloxacin (Spearman's r = 0.297, P = 0.022) was significantly correlated with CDI incidence. Extended-spectrum cephalosporins did not have any effect on CDI incidence.

A Case of Prosthetic Valve Endocarditis with Cerebral Hemorrhage Caused by Rothia mucilaginosa / 대한임상미생물학회지

Rothia spp. are aerobic, gram-positive cocci belonging to the family Micrococcaceae, and are a part of the normal microbial flora of the human oropharynx and upper respiratory tract. We present the first case of the prosthetic valve endocarditis with cerebral hemorrhage caused by Rothia mucilaginosa in South Korea. A 65-year-old man with a prosthetic aortic valve visited the outpatient clinic with a complaint of fever. R. mucilaginosa was identified in one among four sets of blood culture bottles obtained on the on day 30 of fever onset. Brain magnetic resonance imaging (MRI) showed multiple micro-hemorrhages suggesting septic emboli in both the hemispheres, corticomedullary junctions, and cerebellum. Rothia spp. should be considered as a possible pathogen in the cases of infective endocarditis with intracranial hemorrhage.

History and Epidemiology of Bacillary Dysentery in Korea: from Korean War to 2017 / 감염과화학요법

Dysentery has been a major illness for a long time in our country. During Korean war, bacillary dysentery was common illness as well as other infectious diseases such as typhus fever, and Shigella flexneri occupied more than 90% of the cases reported by UN forces. After the war, the Korean National Institute of Health began to monitor the disease as a legal communicable disease. The incidence of dysentery decreased gradually from 1960 through 1980s and consistently low until 1997, and common serotype has changed from S. flexneri to S. sonnei. However, a nationwide epidemic of dysentery occurred at 1998, peaking at 2,462 cases in 2000, and continued until 2004. Most cases were S. sonnei, but the proportion of S. flexneri existed changing with time. There were several major epidemic cases during the period, and the dysentery outbreaks in 1998 and 1999 were associated with nationwide school meal provision which began in 1998. According to the region, Juju island particularly showed a high incidence rate in the period. Since 2005, the nationwide dysentery epidemic was over and incidence of dysentery remained stably low. Recently, multi-drug resistant Shigella infection imported from Southeast Asia appeared, and it requires continuous monitoring and control.

Molecular Epidemiology of Ciprofloxacin-Resistant Escherichia coli Isolated from Community-Acquired Urinary Tract Infections in Korea / 감염과화학요법

Background@#Escherichia coli is the predominant causative pathogen for community-acquired urinary tract infections (UTIs), and the increase in fluoroquinolone-resistant E. coli is of great concern in Korea. The objectives of this study were to investigate the genotypic characteristics and molecular epidemiology of ciprofloxacin-resistant (CIP-R) E. coli isolated from community-acquired UTIs in Korea. @*Materials and Methods@#E. coli samples isolated from the blood or urine were collected from patients with community-acquired acute pyelonephritis aged 15 years and more who were admitted to 12 Korean hospitals from 1st April 2010 to 29th February 2012. Phylogenetic typing, multilocus sequence typing, and molecular characterization of β-lactamase and plasmidmediated quinolone resistance determinants were performed for CIP-R E. coli isolates. @*Results@#A total of 569 E. coli isolates were collected, and 122 (21.4%) isolates were CIP-R isolates. The most prevalent sequence type (ST) was ST131 (28.7%, 35/122), followed by ST393 (14.7%, 18/122), ST1193 (13.1%, 16/122), ST38 (9.0%, 11/122), and ST405 (8.2%, 10/122). The antimicrobial resistance rates of ST131 to cefepime (22.9%, 8/35), ST38 to gentamicin (100%, 11/11), and ST405 to cefotaxime (66.7%, 6/9) were significantly higher than the resistance rates of all other STs combined. Notably, 40% (4/10) of ST405 clones produced extendedspectrum β-lactamases and were co-resistant to trimethoprim/sulfamethoxazole. aac(6′)-1b-cr (20%, 7/35) and CTX-M-14 (40%, 4/10) were more frequently observed in ST131 and ST405 compared with other clones, respectively. @*Conclusions@#Among the CIP-R uropathogenic E. coli isolates in this study, ST131, ST38, and ST405 were specifically associated with antimicrobial resistance.

Ten-year trends in antibiotic usage at a tertiary care hospital in Korea, 2004 to 2013

Background/Aims@#This study was performed to evaluate trends in antibiotic usage at a tertiary care hospital in Korea. @*Methods@#This study collated antibiotic prescription data and total patient days for inpatients at a tertiary care hospital in Korea between 2004 and 2013. The consumption of each class of antibiotic was converted to defined daily dose (DDD)/1,000 patient-days. We defined 3rd generation cephalosporins, 4th generation cephalosporins, β-lactam/β-lactamase inhibitors, and fluoroquinolones as broad-spectrum antibiotics; carbapenems, tigecycline, glycopeptides, oxazolidinone, and polymyxin were defined as antibiotics against multidrug-resistant (MDR) pathogens. Other antibiotic classes were defined as nonbroad-spectrum antibiotics. @*Results@#Mean antibiotic consumption was 920.69 DDD/1,000 patient-days. The proportions of broad-spectrum antibiotics, antibiotics against MDR pathogens, and nonbroad-spectrum antibiotics were 41.8% (384.48/920.69), 3.5% (32.24/920.69), and 54.7% (503.97/920.69), respectively. Consumption of broad-spectrum antibiotics (coefficient for time 0.141; p = 0.049) and antibiotics against MDR pathogens (coefficient for time 0.185; p < 0.001) showed a significant increasing trend over the study period. Nonbroad-spectrum antibiotic consumption showed a significant decreasing trend over the study period (coefficient for time –2.601; p < 0.001). @*Conclusions@#Over the 10-year period, a stepwise increase in the consumption of broad-spectrum antibiotics and antibiotics against MDR pathogens was observed at a tertiary care hospital in Korea. Conversely, during the same period, nonbroad-spectrum antibiotic consumption showed a significant decreasing trend.

Trend of Antibiotic Usage for Hospitalized Community-acquired Pneumonia Cases in Korea Based on the 2010–2015 National Health Insurance Data

Background@#This study is to describe the changes in prescribing practices of antibiotics to treat community-acquired pneumonia (CAP) in Korea during 2010–2015. @*Methods@#The claim database of the Health Insurance Review and Assessment Service in Korea was used to select adult patients (≥ 18 years of age) admitted between 2010 and 2015, with the International Classification of Diseases, Tenth Revision codes relevant to all-cause pneumonia for the first or second priority discharge diagnosis. The episodes with hospital-acquired or healthcare-associated pneumonia were excluded. Consumption of each antibiotic was converted to defined daily dose (DDD) per episode. The amount of antibiotic consumption was compared between patients with CAP aged < 65 years and those aged ≥ 65 years. @*Results@#The average amount of antibiotic consumption per episode was 15.5 DDD, which remained stable throughout the study period (P = 0.635). Patients aged ≥ 65 years received more antibiotics than those aged < 65 years (15.7 vs. 15.3 DDD). Third-generation cephalosporin (4.9 DDD/episode, 31.4%) was the most commonly prescribed, followed by macrolide (2.7 DDD/episode, 17.1%) and beta-lactam/beta-lactamase inhibitor (BL/BLI) (2.1 DDD/episode, 13.6%). The consumption amount of fourth-generation cephalosporin (4th CEP) (P = 0.001), BL/BLI (P = 0.003) and carbapenem (P = 0.002) increased each year during the study period. The consumption of 4th CEP and carbapenem was doubled during 2010–2015. @*Conclusion@#The prescription of broad-spectrum antibiotics such as 4th CEP and carbapenem to treat CAP increased in Korea during 2010–2015.

Association between Antibiotic Consumption and Incidence of Clostridioides difficile Infection in a Hospital

Previous exposure to antimicrobials is a major risk factor for Clostridioides difficile infection (CDI). Antibiotic prescription and C. difficile toxin assay records of patients admitted to a tertiary hospital in Korea from 2009 to 2013 were collected to investigate the association between antibiotic consumption and CDI incidence. A Spearman's correlation analysis between CDI incidence (positive result of toxin assay/10,000 admissions) and antibiotic consumption (defined daily dose/1,000 patient-days) was performed on a monthly basis. Using the matched month approach, we found a significant correlation between CDI rate and moxifloxacin consumption (Spearman's r = 0.351, P < 0.001). Furthermore, using the onemonth delay approach, we found that the consumption of clindamycin (Spearman's r = 0.272, P = 0.037) and moxifloxacin (Spearman's r = 0.297, P = 0.022) was significantly correlated with CDI incidence. Extended-spectrum cephalosporins did not have any effect on CDI incidence.

A Case of Prosthetic Valve Endocarditis with Cerebral Hemorrhage Caused by Rothia mucilaginosa / 대한임상미생물학회지

Rothia spp. are aerobic, gram-positive cocci belonging to the family Micrococcaceae, and are a part of the normal microbial flora of the human oropharynx and upper respiratory tract. We present the first case of the prosthetic valve endocarditis with cerebral hemorrhage caused by Rothia mucilaginosa in South Korea. A 65-year-old man with a prosthetic aortic valve visited the outpatient clinic with a complaint of fever. R. mucilaginosa was identified in one among four sets of blood culture bottles obtained on the on day 30 of fever onset. Brain magnetic resonance imaging (MRI) showed multiple micro-hemorrhages suggesting septic emboli in both the hemispheres, corticomedullary junctions, and cerebellum. Rothia spp. should be considered as a possible pathogen in the cases of infective endocarditis with intracranial hemorrhage.

Atypical Presentation of Pneumocystis jirovecii Infection in HIV Infected Patients: Three Different Manifestations

Advances in the treatment and prevention of Pneumocystis jirovecii infection (PJI) in human immunodeficiency virus (HIV) patients decreased incidence and mortality dramatically, however, it may be associated with an increased frequency of unusual manifestation such as cystic formation, pneumothorax, focal infiltration, nodular formation, or extrapulmonary lesions. We report three cases of PJI with atypical manifestations. Each case demonstrates different clinical features: multiple nodular pulmonary lesion (32-year-old man with abnormal chest X-ray finding), subpleural mass-like lesion (43-year-old man with left visual loss and right pleuritic chest pain), and extrapulmonary mass-like lesions in the liver, lymph nodes, and small bowel (39-year-old man with cough, sputum, and dyspnea). P. jirovecii was confirmed in all 3 cases and they were treated well. It is necessary to understand that PJI shows variable clinical features.

Descriptive Epidemiology of Acute Pyelonephritis in Korea, 2010–2014: Population-based Study

BACKGROUND: Acute pyelonephritis (APN) is one of the most common community-acquired bacterial infections. Recent increases of antimicrobial resistance in urinary pathogens might have changed the other epidemiologic characteristics of APN. The objective of this study was to describe the current epidemiology of APN in Korea, using the entire population. METHODS: From the claims database of the Health Insurance Review and Assessment Service in Korea, the patients with International Classification of Diseases, 10th Revision codes N10 (acute tubulo-interstitial nephritis) or N12 (tubulo-interstitial nephritis, neither acute nor chronic) as the primary discharge diagnosis during 2010–2014 were analyzed, with two or more claims during a 14-day period considered as a single episode. RESULTS: The annual incidence rate of APN per 10,000 persons was 39.1 and was on the increase year to year (35.6 in 2010; 36.7 in 2011; 38.9 in 2012; 40.1 in 2013; 43.8 in 2014, P = 0.004). The increasing trend was observed in both inpatients (P = 0.014) and outpatients (P = 0.004); in both men (P = 0.042) and women (P = 0.003); and those aged under 55 years (P = 0.014) and 55 years or higher (P = 0.003). Eleven times more women were diagnosed and treated with APN than men (men vs. women, 6.5 vs. 71.3), and one of every 4.1 patients was hospitalized (inpatients vs. outpatients, 9.6 vs. 29.4). The recurrence rate was 15.8%, and the median duration from a sporadic episode (i.e., no episode in the preceding 12 months) to the first recurrence was 44 days. The recurrence probability increased with the number of previous recurrences. The average medical cost per inpatient episode was USD 1,144, which was 12.9 times higher than that per outpatient episode (USD 89). CONCLUSION: The epidemiology of APN in Korea has been changing with an increasing incidence rate.

Reply: Is Taking Blood Cultures Indicated in Acute Pyelonephritis Patients Who Have Used Antibiotics before Presentation? / 감염과화학요법

No abstract available.

Reply: Is Taking Blood Cultures Indicated in Acute Pyelonephritis Patients Who Have Used Antibiotics before Presentation? / 감염과화학요법

No abstract available.

Deep Neck Infection with Mediastinal Abscess Treated by Modified Vacuum-Assisted Closure Application

Deep neck infection is a surgical emergency that can result in life threatening complications such as airway obstruction, aspiration, thrombosis of major vessels and mediastinitis by spread of infection along fascial planes. Although appropriate surgical intervention and prompt antibiotics are given, revision surgeries are often required. We report a patient with mediastinal abscess caused by a deep neck infection that was initially intractable with usual surgical drainage but was eventually successfully treated with the modified application of a vacuum-assisted closure (VAC) device (InfoV.A.C. Therapy Unit; Kinetic Concept Inc., USA). We inserted silastic drain tubes into paratracheal area. It was difficult to pack the VAC foams, so they were prone to fail, with complete debridement. With modified VAC therapy assisted by silastic drain tube, the deeply located mediastinal abscess that had been unresponsive to conventional surgical drainage was successfully treated.

Usefulness of Blood Cultures and Radiologic Imaging Studies in the Management of Patients with Community-Acquired Acute Pyelonephritis / 감염과화학요법

BACKGROUND: The objective of this study was to examine the usefulness of blood cultures and radiologic imaging studies for developing therapeutic strategies in community-acquired acute pyelonephritis (CA-APN) patients. MATERIALS AND METHODS: We prospectively collected the clinical data of CA-APN patients who visited 11 hospitals from March 2010 to February 2011. RESULTS: Positive urine and blood cultures were obtained in 69.3% (568/820) and 42.7% (277/648), respectively, of a total of 827 CA-APN patients. Blood culture identified the urinary pathogen in 60 of 645 (9.3%) patients for whom both urine and blood cultures were performed; the organisms isolated from urine were inconsistent with those from blood in 11 and only blood cultures were positive in 49 patients. Final clinical failure was more common in the bacteremic patients than the non-bacteremic ones (8.0% vs. 2.7%, P = 0.003), as was hospital mortality (3.6% vs. 0.3%, P = 0.003). Likewise, durations of hospitalization and fever were significantly longer. Bacteremia was independent risk factor for mortality (OR 9.290, 1.145-75.392, P = 0.037). With regard to radiologic studies, the detection rate of APN was 84.4% (445/527) by abdominal computed tomography and 40% (72/180) by abdominal ultrasonography. Eighty-one of 683 patients (11.9%) were found to have renal abscess, perinephric abscess, urolithiasis, hydronephorosis/hydroureter or emphysematous cystitis, which could potentially impact on clinical management. Patients with Pitt score ≥ 1, flank pain or azotemia were significantly more likely to have such structural abnormalities. CONCLUSION: Blood cultures are clinically useful for diagnosis of CA-APN, and bacteremia is predictive factor for hospital mortality. Early radiologic imaging studies should be considered for CA-APN patients with Pitt scores ≥1, flank pain or azotemia.