Trend of immunity against measles and varicella zoster virus in healthcare workers in Korea.

OBJECTIVE: To examine the seroprevalence of measles and varicella zoster virus (VZV) among healthcare workers (HCW) and evaluate the concordance between self-reported history of previous disease or vaccination and seropositivity. DESIGN: A seroprevalence study and survey. SETTING: A university-affiliated tertiary care hospital. PARTICIPANTS: All HCWs working in high-risk services in 2017 underwent serologic tests and survey; all new HCWs employed in the subsequent years, serologic tests only. METHODS: A serologic study was conducted using chemiluminescence immunoassay (2017) or enzyme immunoassays (2018 and later). HCWs who underwent serological testing in 2017 completed a self-administered questionnaire on their history of infection and vaccination. RESULTS: A total of 10,278 and 9607 HCWs underwent serologic tests for measles and VZV IgG, respectively, from 2017 to 2022. The overall seropositivity rates for measles and VZV were 78.1 % and 92.8 %, respectively. Measles seropositivity declined gradually from >90 % in the HCWs born in the 1960s to <80 % in those born in the 1990s. There was a significant difference in measles seropositivity between the birth cohorts (BCs) 1967-1984 and 1985-1999 (P < 0.001; odds ratio, 1.16; 95 % confidence interval, 1.14-1.18). The seropositivity for VZV was stable, at >90 % in all BCs. The self-reported vaccination history was not independently associated with seropositivity, and the negative predictive value of the survey was very low (9.6 % and 13.1 %, respectively). CONCLUSIONS: Measles seropositivity showed a substantial decline among HCWs born in 1985 or later, while varicella seropositivity remained high. The self-reported vaccination history was not sufficiently reliable for screening HCWs.

The impact of vancomycin-resistant Enterococcus (VRE) screening policy change on the incidence of healthcare-associated VRE bacteremia.

OBJECTIVE: To evaluate the impact of a vancomycin-resistant Enterococcus (VRE) screening policy change on the incidence of healthcare-associated (HA)-VRE bacteremia in an endemic hospital setting. DESIGN: A quasi-experimental before-and-after study. SETTING: A 1,989-bed tertiary-care referral center in Seoul, Republic of Korea. METHODS: Since May 2010, our hospital has diminished VRE screening for admitted patients transferred from other healthcare facilities. We assessed the impact of this policy change on the incidence of HA-VRE bacteremia using segmented autoregression analysis of interrupted time series from January 2006 to December 2014 at the hospital and unit levels. In addition, we compared the molecular characteristics of VRE blood isolates collected before and after the screening policy change using multilocus sequence typing and pulsed-field gel electrophoresis. RESULTS: After the VRE screening policy change, the incidence of hospital-wide HA-VRE bacteremia increased, although no significant changes of level or slope were observed. In addition, a significant slope change in the incidence of HA-VRE bacteremia (change in slope, 0.007; 95% CI, 0.001-0.013; P = .02) was observed in the hemato-oncology department. Molecular analysis revealed that various VRE sequence types appeared after the policy change and that clonally related strains became more predominant (increasing from 26.1% to 59.3%). CONCLUSIONS: The incidence of HA-VRE bacteremia increased significantly after VRE screening policy change, and this increase was mainly driven by high-risk patient populations. When planning VRE control programs in hospitals, different approaches that consider risk for severe VRE infection in patients may be required.

Implementing a multidisciplinary care bundle to reduce colon surgical site infections.

PURPOSE: The aim of this study was to investigate how rates of surgical site infections (SSI) were changed over 2 years after applying colon SSI bundle in patients who underwent colon surgery. METHODS: The multidisciplinary working group developed a care bundle consisting of 8 components, including several recommendations of Surgical Care Improvement Project and monitoring of medical/surgical hand washing. We implemented the care bundle for each patient who underwent colon surgery from April 2013 to December 2014. RESULTS: Overall bundle compliance was 87.9% before implementation, 88.2% in 2013, and 90.5% in 2014. In particular, compliance of the following 3 components was substantial improved during the project period; discontinuation of prophylactic antimicrobial agent within 24 hours of surgery (from 88.3% to 100%), surgical hand washing (from 50.0% to 78.9%), and medical hand washing (from 74.7% to 82.8%). The rate of SSI was 8.0% (12/150) during 3 months before implementation, 3.3% (16/480) from April to December in 2013, and 2.3% (14/607) in 2014. CONCLUSION: After implementation of multidisciplinary care bundle, the compliance of each component was increased and rates of SSIs were significantly decreased compared to those before the quality improvement project.

A contact investigation after exposure to a child with disseminated tuberculosis mimicking inflammatory bowel disease.

PURPOSE: Tuberculosis (TB) is one of the most important diseases that cause significant mortality and morbidity in young children. Data on TB transmission from an infected child are limited. Herein, we report a case of disseminated TB in a child and conducted a contact investigation among exposed individuals. METHODS: A 4-year-old child without Bacille Calmette-Guérin vaccination was diagnosed as having culture-proven disseminated TB. The child initially presented with symptoms of inflammatory bowel disease, and nosocomial and kindergarten exposures were reported. The exposed individuals to the index case were divided into 3 groups, namely household, nosocomial, or kindergarten contacts. Evaluation was performed following the Korean guidelines for TB. Kindergarten contacts were further divided into close or casual contacts. Chest radiography and tuberculin skin test or interferon-gamma-releasing assay were performed for the contacts. RESULTS: We examined 327 individuals (3 household, 10 nosocomial, and 314 kindergarten contacts), of whom 18 (5.5%), the brother of the index patient, and 17 kindergarten children were diagnosed as having latent TB infection (LTBI). LTBI diagnosis was more frequent in the children who had close kindergarten contact with the index case (17.1% vs. 4.4%, P=0.007). None of the cases had active TB. CONCLUSION: This is the first reported case of TB transmission among young children from a pediatric patient with disseminated TB in Korea. TB should be emphasized as a possible cause of chronic diarrhea and failure to thrive in children. A national TB control policy has been actively applied to identify Korean children with LTBI.

Validation of semiautomated surgical site infection surveillance using electronic screening algorithms in 38 surgery categories.

OBJECTIVE: To verify the validity of a semiautomated surgical site infection (SSI) surveillance system using electronic screening algorithms in 38 categories of surgery. DESIGN: A cohort study for validation of semiautomated SSI surveillance system using screening algorithms. SETTING: A 1,989-bed tertiary-care referral center in Seoul, Republic of Korea. METHODS: A dataset of 40,516 surgical procedures in 38 categories stored in the conventional SSI surveillance registry at the Samsung Medical Center between January 2013 and December 2014 was used as the reference standard. In the semiautomated surveillance system, electronic screening algorithms flagged cases meeting at least 1 of 3 criteria: antibiotic prescription, microbial culture, and infectious disease consultation. Flagged cases were audited by infection preventionists. Analyses of sensitivity, specificity, and positive predictive value (PPV) were conducted for the semiautomated surveillance system, and its effect on reducing the workload for chart review was evaluated. RESULTS: A total of 575 SSI events (1·42%) were identified by conventional SSI surveillance. The sensitivity of the semiautomated SSI surveillance was 96·7%, and the PPV of the screening algorithms alone was 4·1%. Semiautomated SSI surveillance reduced the chart review workload of the infection preventionists from 1,283 to 482 person hours per year (a 62·4% decrease). CONCLUSIONS: Compared to conventional surveillance, semiautomated surveillance using electronic screening algorithms followed by chart review of selected cases can provide high-validity surveillance results and can significantly reduce the workload of infection preventionists.

Impact of Targeted Interventions on Trends in Central Line-Associated Bloodstream Infection: A Single-Center Experience From the Republic of Korea.

OBJECTIVE: To assess the impact of targeted interventions on trends in central line-associated bloodstream infection. DESIGN: A before-and-after study between January 2013 and September 2014. SETTING: Tertiary hospital in the Republic of Korea. PATIENTS: All patients with central-line catheters in the hospital. INTERVENTIONS: In September 2013, interventions that targeted central line insertion practices were implemented in 10 ICUs, including compliance monitoring with a central line insertion practices bundle and use of an all-inclusive catheter kit. The impact of targeted interventions on trends in central line-associated bloodstream infection was evaluated by segmented autoregression analysis of an interrupted time series. MEASUREMENTS AND MAIN RESULTS: The average hospital-wide central line-associated bloodstream infection rates in the baseline and intervention periods were 1.84 and 1.56 per 1,000 catheter-days, respectively. During the baseline period, there was an increase of central line-associated bloodstream infection rate of 0.12 per 1,000 catheter-days per month. In the intervention period, there was a decrease of central line-associated bloodstream infection rate of 0.16 per 1,000 catheter-days per month (change in slope, -0.28; 95% CI, -0.37 to -0.19; p < 0.0001). In ICUs, the average central line-associated bloodstream infection rates in the baseline and intervention periods were 1.92 and 1.64 per 1,000 catheter-days, respectively. During the baseline period, there was an increase of central line-associated bloodstream infection rate of 0.18 per 1,000 catheter-days per month in ICUs. After sequential-targeted interventions, there was a decrease of central line-associated bloodstream infection rate of 0.16 per 1,000 catheter-days per month (change in slope, -0.34; 95% CI, -0.50 to -0.18; p = 0.0007). CONCLUSIONS: Targeted interventions were associated with significant changes in trends in the occurrence rate of central line-associated bloodstream infection in ICUs and the entire hospital.

MERS-CoV outbreak following a single patient exposure in an emergency room in South Korea: an epidemiological outbreak study.

BACKGROUND: In 2015, a large outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection occurred following a single patient exposure in an emergency room at the Samsung Medical Center, a tertiary-care hospital in Seoul, South Korea. We aimed to investigate the epidemiology of MERS-CoV outbreak in our hospital. METHODS: We identified all patients and health-care workers who had been in the emergency room with the index case between May 27 and May 29, 2015. Patients were categorised on the basis of their exposure in the emergency room: in the same zone as the index case (group A), in different zones except for overlap at the registration area or the radiology suite (group B), and in different zones (group C). We documented cases of MERS-CoV infection, confirmed by real-time PCR testing of sputum samples. We analysed attack rates, incubation periods of the virus, and risk factors for transmission. FINDINGS: 675 patients and 218 health-care workers were identified as contacts. MERS-CoV infection was confirmed in 82 individuals (33 patients, eight health-care workers, and 41 visitors). The attack rate was highest in group A (20% [23/117] vs 5% [3/58] in group B vs 1% [4/500] in group C; p<0·0001), and was 2% (5/218) in health-care workers. After excluding nine cases (because of inability to determine the date of symptom onset in six cases and lack of data from three visitors), the median incubation period was 7 days (range 2-17, IQR 5-10). The median incubation period was significantly shorter in group A than in group C (5 days [IQR 4-8] vs 11 days [6-12]; p<0·0001). There were no confirmed cases in patients and visitors who visited the emergency room on May 29 and who were exposed only to potentially contaminated environment without direct contact with the index case. The main risk factor for transmission of MERS-CoV was the location of exposure. INTERPRETATION: Our results showed increased transmission potential of MERS-CoV from a single patient in an overcrowded emergency room and provide compelling evidence that health-care facilities worldwide need to be prepared for emerging infectious diseases. FUNDING: None.

Incidence and risk factors of postoperative nausea and vomiting in patients with fentanyl-based intravenous patient-controlled analgesia and single antiemetic prophylaxis.

PURPOSE: We evaluated the incidence and risk factors of postoperative nausea and vomiting (PONV) in patients with fentanyl-based intravenous patient-controlled analgesia (IV-PCA) and single antiemetic prophylaxis of 5-hydroxytryptamine type 3 (5 HT3)-receptor antagonist after the general anesthesia. MATERIALS AND METHODS: In this retrospective study, incidence and risk factors for PONV were evaluated with fentanyl IV-PCA during postoperative 48 hours after various surgeries. RESULTS: Four hundred-forty patients (23%) of 1878 had showed PONV. PCA was discontinued temporarily in 268 patients (14%), mostly due to PONV (88% of 268 patients). In multivariate analysis, female, non-smoker, history of motion sickness or PONV, long duration of anesthesia (>180 min), use of desflurane and intraoperative remifentanil infusion were independent risk factors for PONV. If one, two, three, four, five, or six of these risk factors were present, the incidences of PONV were 18%, 19%, 22%, 31%, 42%, or 50%. Laparoscopic surgery and higher dose of fentanyl were not risk factors for PONV. CONCLUSION: Despite antiemetic prophylaxis with 5 HT3-receptor antagonist, 23% of patients with fentanyl-based IV-PCA after general anesthesia showed PONV. Long duration of anesthesia and use of desflurane were identified as risk factors, in addition to risk factors of Apfel's score (female, non-smoker, history of motion sickness or PONV). Also, intraoperative remifentanil infusion was risk factor independent of postoperative opioid use. As the incidence of PONV was up to 50% according to the number of risk factors, risk-adapted, multimodal or combination therapy should be applied.

Effect-site concentration of remifentanil to prevent cough after laryngomicrosurgery.

OBJECTIVES/HYPOTHESIS: The aim of this study was to discover the optimal effect-site concentration of remifentanil for cough prevention that does not delay awakening or cause respiratory depression during emergence from anesthesia with propofol and remifentanil in laryngomicrosurgery patients. STUDY DESIGN: Prospective, randomized, controlled trial. METHODS: One hundred five patients were randomly assigned to maintain an effect-site concentration (Ce) of remifentanil at a predetermined value of 1 (R1), 1.5 (R1.5), and 2 (R2) ng/mL during emergence. The incidence and grade (0, no coughing; 1, single cough; 2, more than one episode of nonsustained coughing; 3, sustained and repetitive coughing with head lift) of cough, emergence time, blood pressure (MAP), heart rate (HR), spontaneous respiratory rate, oxygen saturation, and postoperative nausea and vomiting (PONV) were recorded during emergence and recovery. RESULTS: The total number of patients with coughing during emergence was lower in groups R1.5 and R2 than in group R1. The cough grade during tracheal extubation was lower in groups R1.5 and R2 than in group R1. In group R2, emergence time was longer and postanesthesia care unit score was lower than in groups R1 and R1.5. Also in group R2, transient hypoventilation and PONV were more frequent compared to group R1. There were no differences in MAP and HR among the three groups during emergence and recovery. CONCLUSIONS: Maintenance of remifentanil at Ce 1.5 and 2 ng/mL suppressed coughing without serious adverse events during emergence from anesthesia with propofol and remifentanil in patients undergoing laryngomicrosurgery.

Incidence and risk factors of acute kidney injury after thoracic aortic surgery for acute dissection.

BACKGROUND: Previous studies have reported a high incidence of acute kidney injury (AKI) after thoracic aortic surgery in heterogeneous patient cohorts, including various aortic diseases and the use of deep hypothermic circulatory arrest. Moderate hypothermia with cerebral perfusion makes deep hypothermia nonessential, but can make end organs susceptible to ischemia during circulatory arrest. We investigated the incidence and risk factors of AKI after thoracic aortic surgery with and without moderate hypothermic circulatory arrest for acute dissection. METHODS: We reviewed the medical records of 98 patients undergoing graft replacement of the thoracic aorta for acute dissection between 2008 and 2011 at a university hospital. Acute kidney injury was defined by RIFLE criteria, which is based on serum creatinine or glomerular filtration rate. RESULTS: The mean age was 55±15 years. The surgical procedures, 96% of which were emergencies, involved the ascending aorta (67%), aortic arch (41%), descending aorta (41%), and aortic valve (5%). Moderate hypothermic circulatory arrest was performed in 75%. The overall incidence of AKI was 54%, and 11% of 98 patients required renal replacement therapy. Thirty-day mortality increased with AKI severity (p=0.002). Independent risk factors for AKI were long cardiopulmonary bypass duration (>180 minutes; odds ratio, 7.50; p=0.008) and preoperative serum creatinine level (odds ratio, 8.43; p=0.016). CONCLUSIONS: Acute kidney injury was common after thoracic aortic surgery for acute dissection with or without moderate hypothermic circulatory arrest and worsened 30-day mortality. Prolonged cardiopulmonary bypass and increased preoperative serum creatinine were independent risk factors for AKI, but moderate hypothermic circulatory arrest was not.