COVID-19 Vaccination and Herd Immunity / 임상당뇨병

Vaccination has been used for the prevention and eradication of communicable diseases such as smallpox, polio, and measles. Herd immunity and immunity threshold have already been conceptualized for the prevention of outbreaks and pandemicity of these diseases. Coronavirus infectious disease-19 (COVID-19) is the second pandemic coronavirus disease of the 21st century. Vaccination has been conducted since December 2020 in an attempt to control the pandemic. The morbidity and incidence of COVID-19 has decreased since the initiation of the vaccination program within Israel, the United Kingdom, and the United States. However, irregular vaccine rollout and uneven distribution of vaccine is a major barrier to vaccine access. Moreover, genetic variants of the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) could be a barrier to immunity.

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

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.

Mortality of Community-Acquired Pneumonia in Korea: Assessed with the Pneumonia Severity Index and the CURB-65 Score

The pneumonia severity index (PSI) and CURB-65 are widely used tools for the prediction of community-acquired pneumonia (CAP). This study was conducted to evaluate validation of severity scoring system including the PSI and CURB-65 scores of Korean CAP patients. In the prospective CAP cohort (participated in by 14 hospitals in Korea from January 2009 to September 2011), 883 patients aged over 18 yr were studied. The 30-day mortalities of all patients were calculated with their PSI index classes and CURB scores. The overall mortality rate was 4.5% (40/883). The mortality rates per CURB-65 score were as follows: score 0, 2.3% (6/260); score 1, 4.0% (12/300); score 2, 6.0% (13/216); score 3, 5.7% (5/88); score 4, 23.5% (4/17); and score 5, 0% (0/2). Mortality rate with PSI risk class were as follows: I, 2.3% (4/174); II, 2.7% (5/182); III, 2.3% (5/213); IV, 4.5% (11/245); and V, 21.7% (15/69). The subgroup mortality rate of Korean CAP patients varies based on the severity scores and CURB-65 is more valid for the lower scores, and PSI, for the higher scores. Thus, these variations must be considered when using PSI and CURB-65 for CAP in Korean patients.

Hypoglycemic Seizures Associated with Pentamidine for Pneumocystis jiroveci Pneumonia in a HIV Patient / 대한내과학회지

Trimethoprim-sulfamethoxazole (TMX-SMZ) is the initial treatment for Pneumocystis jiroveci pneumonia in human immunodeficiency virus (HIV) patients. About 20% of patients do not complete the TMX-SMZ treatment due to treatment failure or adverse reactions. Pentamidine isethionate has been used for P. jiroveci pneumonia as a second-line regimen. Although hypoglycemia is a common adverse effect of pentamidine, pentamidine-induced hypoglycemia has not been reported in Korea. We present an HIV patient with grand mal seizures caused by pentamidine-induced hypoglycemia who was managed successfully with IV dextrose infusion. Mental changes can occur during pentamidine treatment, but hypoglycemia is often ignored and misdiagnosed as epilepsy or stroke. It can result in seizures, coma, and even death. We should be aware of pentamidine-induced hypoglycemia, which can lead to severe neurologic deficits and diabetes mellitus.

Pneumocystis carinii pneumonia in gastric cancer patients without acquired immune deficiency syndrome: 3 cases report and literature review / 대한외과학회지

Pneumocystis carinii pneumonia (PCP) has rarely been reported in solid tumor patients. It is a well-known complication in immunosuppressed states including acquired immune deficiency syndrome and hematologic malignancy. PCP has been reported in solid tumor patients who received long-term steroid treatment due to brain or spinal cord metastases. We found 3 gastric cancer patients with PCP, who received only dexamethasone as an antiemetic during chemotherapy. The duration and cumulative dose of dexamethasone used in each patient was 384 mg/48 days, 588 mg/69 days, and 360 mg/42 days, respectively. These cases highlight that the PCP in gastric cancer patients can successfully be managed through clinical suspicion and prompt treatment. The cumulative dose and duration of dexamethasone used in these cases can be basic data for risk of PCP development in gastric cancer patients during chemotherapy.

Multiple Metastatic Infection Related to Arteriovenous Graft Infection in an ESRD Patient on Hemodialysis / 대한신장학회지

Arteriovenous vascular access infection associated with S. aureus bacteremia may cause metastatic complications, which relate to a poor outcome especially if proper diagnosis and treatment are delayed. We report a case of a 61-year-old male patient on maintenance hemodialysis who developed multiple metastatic infections associated with arteriovenous graft infection caused by methicillin-resistant Staphylococcus aureus (MRSA). At 7th hospital day, multiple metastatic infections, including osteomyelitis of clavicle, vertebral osteomyelitis, and tendinitis of the 5th finger proximal interphalangeal joint, were diagnosed by CT of chest, ultrasonography of hands, and whole body bone scan. Infected arteriovenous graft was removed and antibiotics was administrated for 18 weeks. Thereafter, MRSA bacteremia and clinical symptoms and signs related to metastatic infections were improved.

Bloodstream Infections and Clinical Significance of Healthcare-associated Bacteremia: A Multicenter Surveillance Study in Korean Hospitals

Recent changes in healthcare systems have changed the epidemiologic paradigms in many infectious fields including bloodstream infection (BSI). We compared clinical characteristics of community-acquired (CA), hospital-acquired (HA), and healthcare-associated (HCA) BSI. We performed a prospective nationwide multicenter surveillance study from 9 university hospitals in Korea. Total 1,605 blood isolates were collected from 2006 to 2007, and 1,144 isolates were considered true pathogens. HA-BSI accounted for 48.8%, CA-BSI for 33.2%, and HCA-BSI for 18.0%. HA-BSI and HCA-BSI were more likely to have severe comorbidities. Escherichia coli was the most common isolate in CA-BSI (47.1%) and HCA-BSI (27.2%). In contrast, Staphylococcus aureus (15.2%), coagulase-negative Staphylococcus (15.1%) were the common isolates in HA-BSI. The rate of appropriate empiric antimicrobial therapy was the highest in CA-BSI (89.0%) followed by HCA-BSI (76.4%), and HA-BSI (75.0%). The 30-day mortality rate was the highest in HA-BSI (23.0%) followed by HCA-BSI (18.4%), and CA-BSI (10.2%). High Pitt score and inappropriate empirical antibiotic therapy were the independent risk factors for mortality by multivariate analysis. In conclusion, the present data suggest that clinical features, outcome, and microbiologic features of causative pathogens vary by origin of BSI. Especially, HCA-BSI shows unique clinical characteristics, which should be considered a distinct category for more appropriate antibiotic treatment.

Korean Nosocomial Infections Surveillance System, Intensive Care Unit Module Report: Data Summary from July 2008 through June 2009 and Analysis of 3-Year Results / 병원감염관리

BACKGROUND: In this report, we present the annual data of the intensive care unit (ICU) module of the Korean Nosocomial Infections Surveillance System (KONIS) from July 2008 through June 2009. METHODS: We performed a prospective surveillance of nosocomial urinary tract infections (UTI), bloodstream infections (BSI), and pneumonia (PNEU) at 101 ICUs in 57 hospitals using KONIS. Nosocomial infection (NI) rates were calculated as the numbers of infections per 1,000 patient-days or device-days. RESULTS: We identified 3,287 NIs during the study period: 1,787 UTIs (1,772 cases were urinary catheter-associated), 917 BSIs (797 were central line-associated), and 583 PNEUs (335 were ventilator-associated). The rate of urinary catheter-associated UTIs was 4.80 cases per 1,000 device-days (95% confidence interval, 4.58-5.03) and urinary catheter utilization ratio was 0.85 (0.849-0.851). Although the urinary catheter utilization ratios were lower in the hospitals with 400-699 beds than in the hospitals with 700-899 beds and more than 900 beds, the rates of urinary catheter-associated UTIs were higher in hospitals with 400-699 beds than in the larger ones. The rate of central line-associated BSIs was 3.27 (3.05-3.51) and the utilization ratio was 0.56 (0.559-0.561). The rate of ventilator-associated PNEUs was 1.86 (1.67-2.07) and the utilization ratio was 0.41 (0.409-0.411). The rate of ventilator-associated PNEUs was lower in July 2008-June 2009 than in July 2007-June 2008 and July 2006-December 2006. CONCLUSION: It appears that the KONIS influences the reduction in the rate of device-associated infections, especially ventilator-associated PNEU; therefore, ongoing targeted surveillance and infection control strategies are needed to control device-associated infections.

A case of Haemophilus aphrophilus native valve endocarditis / 대한내과학회지

Haemophilus aphrophilus, a fastidious, gram-negative oropharyngeal species grouped as a HACEK organism, is a rare cause of infective endocarditis. Three cases of endocarditis with Haemophilus aphrophilus were reported in Korea, and all of them required valve replacement surgery. We describe a case of native valve infective endocarditis with cerebral embolism and infarction caused by Haemophilus aphrophilus in a 61-year-old woman who was successfully treated with antibiotic therapy for 6 weeks without valve replacement surgery.

Evaluation of Ceftriaxone Utilization at Multicenter Study

BACKGROUND/AIMS: As bacterial resistance to antimicrobial agents has grown due to the increasing use of antimicrobial agents, we sought to evaluate the suitability of ceftriaxone usage (representative of third generation cephalosporins) at 10 university hospitals in Korea. METHODS: We prospectively evaluated the appropriateness of antibiotic usage in 400 adult patients who received ceftriaxone between February 1, 2006 and June 30, 2006. Drug utilization evaluation (DUE) methods were based on standards set forth by the American Society of Hospital Pharmacists. The DUE criteria used in this study were modified to be more suitable in our hospital setting: justification of drug use, critical and process indications, complications, and outcome measures. RESULTS: The average patient age was 64.4 years. The utilization of ceftriaxone was appropriate in 262 cases (65.5%) for the justification of use, while inappropriate use was observed in 138 cases (34.5%). Common reasons for inappropriate use of ceftriaxone included continued empiric use for presumed infections, prophylactic perioperative injection, and empiric therapy for fever. Most of the critical indications showed a high rate of suitability (66.5-98.5%). Complications occurred in 37 cases (9.3%). With respect to outcome measures, clinical responses were observed in 60.7% of cases, while only 15.7% of cases showed evidence of infection eradication via negative cultures. CONCLUSIONS: Appropriate use (65.5%) of ceftriaxone was higher than inappropriate use (34.5%) at university hospitals in Korea. Inappropriate utilization, however, including continued empiric use for presumed infections and prophylactic perioperative injection remained high. Intensification of educational programs and antibiotic control systems for ceftriaxone is needed to improve the suitability of antimicrobial use.

Comparison between the Surveillance Definitions for Nosocomial Pneumonia Published by the CDC in 1996 and 2002 / 병원감염관리

BACKGROUND: This is a retrospective, descriptive study, evaluating the observed agreement between 1996 & 2002 Centers for Disease Control and Prevention (CDC) definitions of nosocomial pneumonia (NP) for medical intensive care unit (MICU) and surgical intensive care unit (SICU) patients. METHODS: A total of 476 adult patients who were over 15 years of age and had been admitted to the MICU & SICU of a university hospital between August 1, 2005 and August 1, 2007 were enrolled. Data were collected from electronic medical records according to the 1996 & 2002 CDC definitions of NP. RESULTS: According to the 1996 CDC definitions of NP, there were a total of 116 NP cases and incidence rate was 11.6 per 1,000 patient-days; when analyzed with the 2002 CDC definitions of NP, 75 cases met the criteria and the incidence rate was 7.5 per 1,000 patient-days. Kappa value measuring agreement between the two definitions was 0.67 (95% confidence interval 0.601-0.706). When 1996 CDC definitions were compared with 2002 CDC definitions, sensitivity, specificity, positive predictive value, and negative predictive value were 93.3, 88.5, 60.3, and 98.6%, respectively. CONCLUSION: Even though the aforementioned NP criteria had been applied to the same study population, the number of patients that met the definitions changed depending on which criteria had been used. Therefore, it is necessary to consider the differences when making a comparison.

Korean Nosocomial Infections Surveillance System, Intensive Care Unit Module Report: Data Summary from July 2007 through June 2008 / 병원감염관리

BACKGROUND: This is the first annual data on the surveillance of intensive care unit (ICU) module by the Korean Nosocomial Infections Surveillance System (KONIS) from July 2007 through June 2008. METHODS: The KONIS performed a prospective surveillance for nosocomial urinary tract infections (UTI), bloodstream infections (BSI), and pneumonia (PNEU) at 96 ICUs in 56 hospitals. Nosocomial infection (NI) rates were calculated as the numbers of infections per 1,000 patient-days or device-days. RESULTS: A total of 2,637 NIs were found during the study period; 1,391 UTIs (1,365 cases were urinary catheter-associated), 667 BSIs (563 were central line-associated), and 579 PNEUs (357 were ventilator-associated). The rate of urinary catheter-associated UTIs was 4.43 cases per 1,000 device-days (95% confidence interval, 4.20-4.67) and urinary catheter utilization ratio was 0.84 (0.839-0.841). The rate of central line-associated BSIs was 2.83 (2.61-3.07) and the utilization ratio was 0.54 (0.538-0.542). The rate of ventilator-associated PNEUs was 2.49 (2.25-2.76) and the utilization ratio was 0.39 (0.388-0.392). Although the ventilator utilization ratios were lower in the hospitals with less than 900 beds than in the hospitals with more than 900 beds, the rates of ventilator-associated PNEUs were higher in the smaller hospitals than in the larger ones. CONCLUSION: This result suggests that ongoing targeted surveillance and implementation of proven infection control strategies are needed.

Retraction: Changing Trends in Antimicrobial Resistance Among Invasive Pneumococcal Pathogens in Asian Countries: Asian Network for Surveillance of Resistant Pathogens (ANSORP) Study / 감염과화학요법

No abstract available.

Retraction: Changing Trends in Antimicrobial Resistance Among Invasive Pneumococcal Pathogens in Asian Countries: Asian Network for Surveillance of Resistant Pathogens (ANSORP) Study / 감염과화학요법

No abstract available.

A case of necrotizing fasciitis caused by Klebsiella pneumoniae secondary to chronic otitis media / 대한내과학회지

Necrotizing fasciitis is a relatively uncommon infectious disorder where a bacterial organism penetrates the subcutaneous tissues and superficial fascia, ultimately causing necrosis of vast areas of soft tissue. Although invasive Streptococcus spp., most commonly group-A streptococci, is the most frequent cause of this disorder, in a single organism-infection, necrotizing fasciits caused by Klebseilla pneumoniae is becoming more frequently reported, perhaps due to the recent increase in the frequency of diabetes and liver diseases. Necrotizing fasciitis caused by K. pneumoniae is usually secondary to hematogenous dissemination, most commonly caused by trauma or liver abscess and usually results in multiple organ failure. The progression of the disease is so rapid that the mortality rate is high despite aggressive surgical intervention and extensive use of antibiotics at an early disease stage. Here we report a case of necrotizing fasciitis caused by hematogenously spread K. pneumoniae from incompletely treated chronic otitis media in a patient with alcoholic liver cirrhosis and diabetes.

Profiles of infectious complications on the outcomes for the recipients of allogeneic hematopoietic stem cell transplantation / 대한내과학회지

BACKGROUND: We wanted to investigate the effect of infectious complications on the outcome of patients who received allogeneic hematopoietic stem cell transplantation (HSCT), and we determined the risk factors for predicting infectious complication and the mortality in allogeneic HSCT recipients. METHODS: We enrolled all the patients who underwent allogeneic HSCT at Samsung Medical Center from February 1996 to October 2003. RESULTS: A total of 139 patients were enrolled. A total of 450 infectious episodes were observed in 131 allogeneic recipients (90.8%). Infectious complications occurred in the allogeneic recipients [3.243.00 episodes/patient]. Microbiologically documented infection (MDI), clinically documented infection (CDI), and unknown fever (UF) accounted for 41.6%, 34.0% and 24.4%, respectively, of the total infections. Pneumonia (15.1%) was the most common infection. Among the 187 MDIs, bacterial infection, viral infection and fungal infection accounted for 50.3%, 39.6%, and 7.5%, respectively. Twelve of 24 deaths in the late post-transplantation period were related with infection. The statistically significant risk factors for infection related to mortality, by multivariate analysis, were the underlying disease risk, the duration of neutropenia, the failure of stem cell engraftment, acute GVHD, MDI, UF, the number of infectious episodes, bacteremia, fungemia, pneumonia, genitourinary tract infections, S. aureus, E. coli, Pseudomonas spp., Aspergillus spp., Non-albicans candida and CMV diseases. CONCLUSIONS: The incidence of fungal infections was still low in our institute, even though prophylaxis for fungal infections was not applied, except for gargling with nystatin. In addition, most of them were non-albican Candida and Aspergillus species. Therefore, routine fluconazole prophylaxis may not be needed in our institute.

Clinical Significance of Bacteremia Caused by Viridans Streptococci / 감염과화학요법

BACKGROUND: Clinical significance of viridans streptococcal bacteremia may be variable from insignificant colonization to serious invasive diseases such as endocarditis. However, there have been no data on the clinical implications of viridans streptococcal bacteremia in Korea to date. MATERIALS AND METHODS: We have analyzed 95 cases of viridans streptococcal bacteremia diagnosed at the Samsung Medical Center from 1997 to 2003. All available clinical and microbiological data were analyzed. RESULTS: Of the total 95 cases, 76 (80%) had clinically significant infections, while 20% of cases were not associated with clinical diseases. Primary bacteremia was the most common disease (48%) followed by intra-abdominal infections (15%), and infective endocarditis (8%). Primary bacteremia was mostly observed in patients with neutropenia after anti-cancer chemotherapy. Infective endocarditis was unlikely if patients did not have underlying heart diseases. S. mitis, S. oralis, and S. intermedius were the most common etiologic agent in infective endocarditis, primary bacteremia, and intra-abdominal infection, respectively. Thirty-eight percent of isolates were not susceptible to penicillin. CONCLUSION: Viridans streptococcal bacteremia is likely to be associated with invasive clinical diseases, especially in patients with neutropenia, intra-abdominal diseases or underlying heart diseases. However, the presence of viridans streptococci in the blood cultures does not necessarily mean the possibility of infective endocarditis.

Urinary Tract Infections in Renal Transplant Recipients / 감염과화학요법

BACKGROUND: To evaluate urinary tract infections (UTI) in renal transplant recipients in setting where TMP-SMX resistance is quite common. MATERIALS AND METHODS: All patients underwent renal transplantation at Samsung Medical Center from January 1998 to August 2002 were included with the completion of 2 year-follow-up. TMP- SMX was prophylactically administered during 12 months after renal transplantation. Their medical records and microbiologic data were reviewed, retrospectively. RESULTS: A total of 336 patients were enrolled (male to female ratio, 191:145; mean age, 39+/-10 years). 146 episodes of UTI were observed in 104 patients (31.0%) within 2 years after renal transplantation. 52 episodes (35.6%) developed during post-transplantation 30 days, and 87 episodes (59.6%) within post-transplantation 6 months. There was no difference in the incidence of UTI with regard to the type of immunosuppressants (P=0.371) or graft rejections (P=0.291). Among the isolated strains, Escherichia coli (E. coli) (51.4%) was the most common, followed by Enterococcus species (12.3%), Pseudomonas species (6.8%), Enterobacter species (6.1%), Coagulase-negative staphylococci (5.5%), and Klebsiella species (5.5%). Among 75 E. coli isolates, rates of resistance to TMP-SMX, ciprofloxacin, ampicillin-sulbactam and ceftriaxone were 62.7%, 34.7%, 33.3%, and 1.0%, respectively. There was no difference in mortality rate related with the occurrence of UTI (P= 0.754). CONCLUSION: Despite high prevalence of TMP-SMX resistance, post-transplantation UTI is usually mild and does not seem to predispose to increase graft rejection or patient mortality. Nevertheless, because most common episodes of UTI occur within 1 or 6 months of transplantation, further studies are warranted to evaluate if additional preventive strategies during early period are needed.

Clinical Manifestations of Posttransplantation Lymphoproliferative Disorder (PTLD) after Liver Transplantation / 감염과화학요법

BACKGROUND: Post-transplantation lymphoproliferative disorder (PTLD) after liver transplantation is a rare but potentially fatal disease. Clinical manifestations and prevalence of PTLD after liver transplantation in Korea have not been investigated thoroughly. MATERIALS AND METHODS: A retrospective chart review was done for 284 liver transplant recipients at Samsung Medical Center, Seoul, Korea during the period from 1996 to 2003. RESULTS: The incidence of PTLD after liver transplantation was 3.9% (11/284). PTLDs were more prevalent in children (9/55, 16.4%) than in adults (2/237, 0.9%; P<0.01). Among the PTLD patients, four cases were male (36.3%) and seven were female (63.7%). Median time from the transplantation to PTLD diagnosis was 9 months. The type of PTLD was as follows:early lesion (6 cases, 54.5%), polymorphic PTLD (3 cases, 27.3%), and B cell lymphoma (2 cases, 18.2%). PTLDs were more prevalent in the patients with cyclosporine use (OR 13.28, 95% CI:1.29-136.31, P=0.03), acute rejection (OR 5.63, 95% CI:1.03-30.62, P=0.04), and negative serology for EBV VCA IgG (OR 19.15, 95% CI:1.99-183.98, P=0.01) by multivariate logistic regression. Three patients (27.3%) died of B cell lymphoma (2 cases) and polymorphic PTLD (1 case). The remaining patients were improved with reduction of immunosuppression and treatment with acyclovir. CONCLUSION: The incidence of PTLD was high in children. The risk factors of PTLD were negative serology for EBV VCA IgG, history of acute rejection, and cyclosporine use. Considering the poor prognosis of PTLD, effective strategies for prevention and early diagnosis for early treatment should be emphasized.

Clinical Significance of Bacteremia Caused by Viridans Streptococci / 감염과화학요법

BACKGROUND: Clinical significance of viridans streptococcal bacteremia may be variable from insignificant colonization to serious invasive diseases such as endocarditis. However, there have been no data on the clinical implications of viridans streptococcal bacteremia in Korea to date. MATERIALS AND METHODS: We have analyzed 95 cases of viridans streptococcal bacteremia diagnosed at the Samsung Medical Center from 1997 to 2003. All available clinical and microbiological data were analyzed. RESULTS: Of the total 95 cases, 76 (80%) had clinically significant infections, while 20% of cases were not associated with clinical diseases. Primary bacteremia was the most common disease (48%) followed by intra-abdominal infections (15%), and infective endocarditis (8%). Primary bacteremia was mostly observed in patients with neutropenia after anti-cancer chemotherapy. Infective endocarditis was unlikely if patients did not have underlying heart diseases. S. mitis, S. oralis, and S. intermedius were the most common etiologic agent in infective endocarditis, primary bacteremia, and intra-abdominal infection, respectively. Thirty-eight percent of isolates were not susceptible to penicillin. CONCLUSION: Viridans streptococcal bacteremia is likely to be associated with invasive clinical diseases, especially in patients with neutropenia, intra-abdominal diseases or underlying heart diseases. However, the presence of viridans streptococci in the blood cultures does not necessarily mean the possibility of infective endocarditis.