The Impact of an Antimicrobial Stewardship Program on Days of Therapy in the Pediatric Center:An Interrupted Time-Series Analysis of a 19-Year Study

Background@#We aimed to analyze the effects of an antimicrobial stewardship program (ASP) on the proportion of antimicrobial-resistant pathogens in bacteremia, antimicrobial use, and mortality in pediatric patients. @*Methods@#A retrospective single-center study was performed on pediatric inpatients under 19 years old who received systemic antimicrobial treatment from 2001 to 2019. A pediatric infectious disease attending physician started ASP in January 2008. The study period was divided into the pre-intervention (2001–2008) and the post-intervention (2009–2019) periods. The amount of antimicrobial use was defined as days of therapy per 1,000 patientdays, and the differences were compared using delta slope (= changes in slopes) between the two study periods by an interrupted time-series analysis. The proportion of resistant pathogens and the 30-day overall mortality rate were analyzed by the χ2 . @*Results@#The proportion of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae bacteremia increased from 17% (39 of 235) in the pre-intervention period to 35% (189 of 533) in the post-intervention period (P < 0.001). The total amount of antimicrobial use significantly decreased after the introduction of ASP (delta slope value = −16.5; 95% confidence interval [CI], −30.6 to −2.3; P = 0.049). The 30-day overall mortality rate in patients with bacteremia did not increase, being 10% (55 of 564) in the pre-intervention and 10% (94 of 941) in the post-intervention period (P = 0.881). @*Conclusion@#The introduction of ASP for pediatric patients reduced the delta slope of the total antimicrobial use without increasing the mortality rate despite an increased incidence of ESBL-producing gram-negative bacteremia.

Molecular Epidemiology of Bacillus cereus in a Pediatric Cancer Center

PURPOSE: Bacillus cereus has been reported as the cause of nosocomial infections in cancer patients. In our pediatric cancer ward, a sudden rise in the number of patients with B. cereus bacteremia was observed in 2013 to 2014. This study was performed to investigate the molecular epidemiology of increased B. cereus bacteremia cases in our center. METHODS: Pediatric cancer patients who developed B. cereus bacteremia were identified from January 2001 to June 2014. The B. cereus bacteremia in this study was defined as a case in which at least one B. cereus identified in blood cultures, regardless of true bacteremia. Available isolates were further tested by multilocus sequence typing (MLST) analysis. A retrospective chart review was performed. RESULTS: Nineteen patients developed B. cereus bacteremia during the study period. However, in 2013, a sudden increase in the number of patients with B. cereus bacteremia was observed. In addition, three patients developed B. cereus bacteremia within 1 week in July and the other three patients within 1 week in October, respectively, during emergency room renovation. However, MLST analysis revealed different sequence types without consistent patterns. Before 2013, five tested isolates were ST18, ST26, ST177, and ST147-like type, and ST219-like type. Isolates from 2013 were ST18, ST73, ST90, ST427, ST784, ST34-like type, and ST130-like type. CONCLUSIONS: MLST analyses showed variable ST distribution of B. cereus isolates. Based on this study, there was no significant evidence suggesting a true outbreak caused by a single ST among patients who developed B. cereus bacteremia.

Stenotrophomonas maltophilia and Ventilator-Associated Pneumonia in Critically Ill Pediatric Patients: a Retrospective Analysis at a Single Center

PURPOSE: Ventilator-associated pneumonia (VAP) is a serious threat in critically ill pediatric patients. Data regarding Stenotrophomonas maltophilia VAP in pediatric population is limited. We evaluated the clinical data of S. maltophilia associated VAP in critically ill pediatric patients. METHODS: A retrospective chart review was performed in pediatric patients 18 years old or younger who developed S. maltophilia associated VAP at Samsung Medical Center, Seoul Korea from January 2008 to December 2012. RESULTS: A total of 31 patients were identified S. maltophilia associated VAP. Median age was 8 months (range, 0.5 month to 16.6 years) and 13 patients were male (40.6%). Underlying illnesses were cardiologic diseases (n=11, 34.4%), hematologic oncologic malignancies (n=7, 25%), neurologic diseases (n=4, 12.5%), pulmonary diseases (n=3, 9.4%), and others (n=4, 12.5%). The median duration of ventilator use before S. maltophilia VAP diagnosis was 14 days (range, 4-256 days). Overall mortality at 30 days was 12.5% (4/32). CONCLUSIONS: S. maltophilia should be also considered as a possible pathogen for VAP in critically ill pediatric patients. Empiric antibiotic choice should include agents that are active against S. maltophilia in patients who are deteriorating on broad spectrum beta-lactam antimicrobial agents.

Effectiveness of Varicella Zoster Immune Globulin Administration within 96 Hours versus more than 96 Hours after Exposure to the Varicella-Zoster Virus

PURPOSE: Varicella Zoster Immune Globulin (VZIG) is available in Korea for post-exposure prophylaxis of the Varicella-zoster virus (VZV) in high-risk patients. In July 2013, the United States Centers for Disease Control and Prevention (US CDC) recommended extending the time for administration of VariZIG(R) from within 96 hours up to 10 days after VZV exposure. This study was performed to analyze the effectiveness of VZIG prophylaxis between the two groups of patients who received VZIG within 96 hours and more than 96 hours of exposure to varicella. METHODS: A retrospective chart review was performed in pediatric patients who received VZIG at Samsung Medical Center, Seoul, Korea from January 2001 to December 2012. RESULTS: A total of 91 patients were identified. Fifty-seven patients were male (62.6%) and the median age was 5.91 years. Thirty-nine patients (42.9%) were exposed to VZV in the hospital. Underlying diseases were solid tumors (41.8%), hematologic malignancies (40.7%), and others (17.5%). Forty-five patients (49.5%) were hematopoietic cell transplant recipients. Seventy-four patients (81.3%) received VZIG within 96 hours after VZV exposure. There was no significant difference in the development of chickenpox between the two groups (2.7% vs. 5.9%, P=0.4664). In 22 seronegative patients, we also observed no significant difference between the groups in terms of the development of chickenpox (6.6% vs. 0%, P=0.667). CONCLUSIONS: This study showed that the effectiveness of VZIG for the prevention of chickenpox was comparable between patients who received VZIG within 96 hours and those who received VZIG more than 96 hours after exposure to VZV.

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.

Usefulness of Influenza Rapid Antigen Test in Influenza A (H1N1) / 소아알레르기및호흡기학회지

PURPOSE: The aim of this study was to examine the sensitivity and specificity of the influenza rapid antigen test, in comparison with reverse transcription polymerase chain reaction (RT-PCR), according to the time of the test from symptom onset and the clinical manifestations in the patients tested for suspected infection of the influenza A (H1N1) at a second hospital. METHODS: A total of 529 pediatric patients, aged between 6 and 12 years old, who visited the emergency department from October 1, 2009 to December 31, 2009, received the influenza rapid antigen test and RT-PCR. We examined the sensitivity and specificity of the influenza rapid antigen test in comparison with RT-PCR according to the time of the test from symptom onset (72 hours) and clinical manifestations (fever, cough, rhinorrhea.nasal obstruction, sore throat, gastrointestinal symptoms, and general symptoms) in a retrospective study based on hospital charts. RESULTS: The sensitivity of the influenza rapid antigen test at elapsed times of less than 24 hours, 24 to 48 hours, and 48 to 72 hours after the onset of the symptoms was 53.9%, 61.4%, and 62.1% respectively. When the elapse time was greater than 72 hours, the sensitivity was 31.6%; thus, the sensitivity of the influenza rapid antigen test tended to decrease with elapsed time. The sensitivity of the test was 79% in patients presenting with gastrointestinal symptoms, which was the highest, but there was no statistical difference according to the clinical manifestations of the patients. CONCLUSION: Our study suggests that more accurate results might be gained when the influenza rapid antigen test is performed within 72 hours after symptom onset.

A Case of Early Gastric Cancer Diagnosed from the Area of Ulcer Scar and Showing Part of Malignant Cycle / 대한소화기내시경학회지

In the case of IIc type of early gastric cancer occuring from the area of ulcer sear, endoscopic differentiation between it and beoign ulcer scar is occasionally very difficult, due to the absence of characteristic malignant features. The presence of the irregular granular mucosal changes on the area of ulcer scar may be very helpful in the differential diagnosis between early gastric cancer and benign ulcer sear. And underetanding of the malignant cycle of early gaetric cancer is very important for the diagnosis of the depressed forms of early gastric cancer, We experienced and report a cases of IIc type of early gastric cancer diagnosed before operation by the endoscopic finding of irregular granular mucoeal changes on the area of ulcer scar and showing part of malignant cycle.