Comparison of the Clinical Outcomes of Patients With Positive Xpert Carba-R Tests for Carbapenemase-Producing Enterobacterales According to Culture Positivity.

BACKGROUND: We aimed to compare the clinical outcomes of patients with positive Xpert Carba-R assay results for carbapenemase-producing Enterobacterales (CPE) according to CPE culture positivity. METHODS: We retrospectively collected data for patients with positive CPE (positive Xpert Carba-R or culture) who underwent both tests from August 2018 to March 2021 in a 2700-bed tertiary referral hospital in Seoul, South Korea. We compared the clinical outcomes of patients positive for Xpert Carba-R according to whether they were positive (XPCP) or negative (XPCN) for CPE culture. RESULTS: Of 322 patients with CPE who underwent both Xpert Carba-R and culture, 313 (97%) were positive for Xpert Carba-R for CPE. Of these, 87 (28%) were XPCN, and 226 (72%) were XPCP. XPCN patients were less likely to have a history of previous antibiotic use (75.9% vs 90.3%; P = .001) and to have Klebsiella pneumoniae carbapenemase (21.8% vs 48.9%; P < .001). None of the XPCN patients developed infection from colonization within 6 months, whereas 13.4% (29/216) of the XPCP patients did (P < .001). XPCN patients had lower transmission rates than XPCP patients (3.0% [9/305] vs 6.3% [37/592]; P = .03). There was no significant difference in CPE clearance from positive culture results between XPCN and XPCP patients (40.0% [8/20] vs 26.7% [55/206]; P = .21). CONCLUSIONS: Our study suggests that XPCN patients had lower rates of both infection and transmission than XPCP patients. The Xpert Carba-R assay is clinically useful not only for rapid identification of CPE but also for predicting risks of infection and transmission when performed along with culture.

Nosocomial Outbreak of COVID-19 in a Hematologic Ward.

BACKGROUND: Coronavirus disease 2019 (COVID-19) outbreaks occur in hospitals in many parts of the world. In hospital settings, the possibility of airborne transmission needs to be investigated thoroughly. MATERIALS AND METHODS: There was a nosocomial outbreak of COVID-19 in a hematologic ward in a tertiary hospital, Seoul, Korea. We found 11 patients and guardians with COVID-19 through vigorous contact tracing and closed-circuit television monitoring. We found one patient who probably had acquired COVID-19 through airborne-transmission. We performed airflow investigation with simulation software, whole-genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). RESULTS: Of the nine individuals with COVID-19 who had been in the hematologic ward, six stayed in one multi-patient room (Room 36), and other three stayed in different rooms (Room 1, 34, 35). Guardian in room 35 was close contact to cases in room 36, and patient in room 34 used the shared bathroom for teeth brushing 40 minutes after index used. Airflow simulation revealed that air was spread from the bathroom to the adjacent room 1 while patient in room 1 did not used the shared bathroom. Airflow was associated with poor ventilation in shared bathroom due to dysfunctioning air-exhaust, grill on the door of shared bathroom and the unintended negative pressure of adjacent room. CONCLUSION: Transmission of SARS-CoV-2 in the hematologic ward occurred rapidly in the multi-patient room and shared bathroom settings. In addition, there was a case of possible airborne transmission due to unexpected airflow.

Adverse Reactions of the Second Dose of the BNT162b2 mRNA COVID-19 Vaccine in Healthcare Workers in Korea.

We conducted a prospective, mobile-based survey on the self-reported adverse reactions in healthcare workers (HCWs) who received both doses of the BNT162b2 mRNA vaccine. Of the 342 HCWs who completed the two-dose vaccination, 265 (77.5%) responded to the survey at least once. Overall, the rates of adverse reactions were higher after the second dose compared with the first dose (89.1% vs. 80.1%, P = 0.006). The most common systemic reactions were muscle ache (69.1%), fatigue (65.7%), headache (48.7%), chills (44.2%), and fever (32.1%), and were notably more common after the second dose vaccine as well. We also noted a sex difference in which the frequency of adverse reactions after the second dose of the vaccine was significantly higher in females, which was not observed after the first dose. The rates of adverse reactions were lower in older age groups, and the rates and severities of the adverse reactions decreased during the 3-day period following vaccination.

Fit-failure rate associated with simulated reuse and extended use of N95 respirators assessed by a quantitative fit test.

OBJECTIVE: We quantitatively assessed the fit failure rate of N95 respirators according to the number of donning/doffing and hours worn. DESIGN: Experimental study. SETTING: A tertiary-care referral center in South Korea. PARTICIPANTS: In total, 10 infection control practitioners participated in the fit test. METHODS: The first experiment comprised 4 consecutive 1-hour donnings and fit tests between each donning. The second experiment comprised 2 consecutive 3-hour donnings and fit tests between each donning. The final experiment comprised fit tests after an 1-hour donning or a 2-hour donning. RESULTS: For 1-hour donnings, 60%, 70%, and 90% of the participants had fit failures after 2, 3, and 4 consecutive donnings, respectively. For 3-hour donnings, 50% had fit failure after the first donning and 70% had failures after 2 consecutive donnings. All participants passed the fit test after refitting whenever fit failure occurred. The final experiment showed that 50% had fit failure after a single use of 1 hour, and 30% had fit failure after a single use of 2 hours. CONCLUSIONS: High fit-failure rates were recorded after repeated donning and extended use of N95 respirators. Caution is needed for reuse (≥1 time) and extended use (≥1 hour) of N95 respirators in high-risk settings such as those involving aerosol-generating procedures. Although adequate refitting may recover the fit factor, the use of clean gloves and strict hand hygiene afterward should be ensured when touching the outer surfaces of N95 respirators for refitting.

Frequency of and risk factors for reversion of QuantiFERON test in healthcare workers in an intermediate-tuberculosis-burden country.

OBJECTIVES: High-risk healthcare workers (HCWs) are often screened for latent tuberculosis infection (LTBI) using QuantiFERON tests (QFTs), with annual serial tests often showing reversion from positive to negative results. We assessed the frequency of and risk factors for reversion of QFTs in HCWs in an intermediate-tuberculosis burden country. METHODS: We enrolled high-risk HCWs at a tertiary-care hospital in South Korea, who were assessed by QFTs at least twice between 2017 and 2019. RESULTS: Of the 1870 HCWs screened, 1542 (82%) had persistent negative results, 229 (12%) had persistent positive results, 53 (3%) showed reversion, and 46 (2%) showed conversion from negative to positive. Multivariate analysis comparing the characteristics of the 229 HCWs with persistent positive results and the 53 who experienced reversion showed that older age (adjusted odds ratio (aOR): 0.96; 95% confidence interval (CI): 0.92-0.99), male sex (aOR: 0.29; 95% CI: 0.11-0.78) and high (≥0.70 IU/mL) baseline QFT results (aOR: 0.15; 95% CI: 0.07-0.31) were inversely associated with reversion. Using an ROC curve-derived cut-off of <0.738 IU/mL, the area under the curve was 0.79. Of 53 HCWs with reversion, 36 (78%) had below 0.738 IU/mL of baseline QFT, while 181 (79%) of 229 HCWs without reversion had above 0.738 IU/mL of baseline QFT. CONCLUSION: Reversion during serial testing is unlikely in HCWs who are male, older in age, and have higher baseline QFT results. Serial testing without LTBI treatment may be indicated in HCWs who are female, younger and, especially, have lower QFT results.

Importance of Follow-Up Microscopic Examination in Hospitalized Patients with Confirmed Scabies.

We investigated the duration of positive microscopic examination in hospitalized patients with confirmed scabies in an acute care hospital. We included hospitalized patients who were diagnosed with scabies between January 2015 and June 2019. From the study period, a total of 31 patients with confirmed scabies were identified. Median age was 75 years. Of a total of 31 patients with confirmed scabies, six were discharged or transferred before getting a negative microscopic test result. Of the remaining 25 patients with negative microscopic test results, the median duration from diagnosis to a negative microscopic test result was 14 days (interquartile range, 9-17). Given that nosocomial outbreaks lead to high workload and considerable resource consumption, adequate treatment, sufficient follow-up examination, and confirmation of cure are warranted before releasing contact isolation.

The Rate of Acquisition of Carbapenemase-Producing Enterobacteriaceae among Close Contact Patients Depending on Carbapenemase Enzymes.

BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) are highly drug-resistant pathogens. Screening the contacts of newly-identified CPE patients is crucial for nosocomial transmission control. We evaluated the acquisition rate of CPE in close contacts as a function of CPE genotype. MATERIALS AND METHODS: This study was conducted in Asan Medical Center, a 2,700-bed, tertiary teaching hospital in Seoul, Korea, between November 2010 and October 2017. Index cases were defined as patients with positive tests for CPE from any infected or colonized site during hospitalization who had no direct epidemiologic linkage with existing CPE patients; close contact patients were defined as those whose hospital stay overlapped with the stay of an index case for at least one day and who occupied the same room or intensive care unit (ICU). Secondary patients were defined as those who produced positive CPE culture isolates from surveillance cultures that had the same CPE enzyme as that of the index case patients. RESULTS: A total of 211 index case patients and 2,689 corresponding contact patients were identified. Of the contact patients, 1,369 (50.9%) including 649 New-Delhi metallo-beta-lactamase-1 (NDM-1) and 448 Klebsiella pneumoniae carbapenemase (KPC)-producing CPE exposures were screened, and 44 secondary patients (3.2%; 95% confidence interval 2.3 - 4.3%) were positive for NDM-1-producing CPE (16 patients) and KPC-producing (24 patients) CPE. The CPE acquisition rate (5.4%) for KPC-producing CPE exposures was significantly higher than that for NDM-1 exposures (2.7%) (P = 0.01). CONCLUSION: The CPE acquisition rate was 3.2% among close contacts sharing a multi-patient room, with about a two-fold higher risk of KPC-producing CPE than NDM-1-producing CPE.

Seroprevalence of mumps in healthcare workers in South Korea.

Mumps is contagious disease and maintaining immunity to mumps in healthcare worker (HCW) is important for preventing transmission in the hospital. We evaluated the seroprevalence of mumps in HCWs in a tertiary care hospital in Republic of Korea. A total of 6,055 HCWs born between 1950 and 1995 underwent antibody testing. The overall seropositivity rate of mumps was 87% (95% confidence interval, 86%-87%). Our data indicates that, in Korean HCWs, testing for mumps antibody followed by mumps vaccination is more appropriate than routine mumps vaccination without testing for mumps antibody.

Candida auris colonization or infection of the ear: A single-center study in South Korea from 2016 to 2018.

Candida auris was first identified in Japan from specimens obtained from the ear, but most reports since have reported invasive infections or non-ear based cases. We reviewed all the microbiology records from a single center in South Korea from February 2016 to July 2018. One hundred eleven isolates were positive for C. auris from 79 patients. All 79 patients positive for C. auris had positive ear discharge samples. All but one of the patients with C. auris had been to the otorhinolaryngology clinic. Symptom-driven ear culture was done for all but one patient, whose culture was performed for surveillance. Ear discharges were mostly purulent (60%) or serous (34%). We performed the environmental cultures at the otorhinolaryngology outpatient clinic to evaluate the environmental contamination of C. auris, but C. auris was not isolated from medical equipment and environmental surfaces.

Airborne fungal spores and invasive aspergillosis in hematologic units in a tertiary hospital during construction: a prospective cohort study.

Background: Invasive aspergillosis (IA) is an opportunistic fungal infection that mostly occurs in immunocompromised patients, such as those having hematologic malignancy or receiving hematopoietic stem cell transplantation. Inhalation of Aspergillus spores is the main transmission route of IA in immunocompromised patients. Construction work in hospitals is a risk factor for environmental fungal contamination. We measured airborne fungal contamination and the incidence of IA among immunocompromised patients, and evaluated their correlation with different types of construction works. Methods: Our tertiary hospital in Seoul, Korea underwent facility construction from September 2017 to February 2018. We divided the entire construction period into period 1 (heavier works: demolition and excavation) and period 2 (lighter works: framing, interior designing, plumbing, and finishing). We conducted monthly air sampling for environmental spore surveillance in three hematologic wards. We evaluated the incidence of IA among all immunocompromised patients hospitalized in the three hematologic wards (2 adult wards and 1 pediatric ward) during this period. IA was categorized into proven, probable, and possible aspergillosis based on the revised European Organization for Research and Treatment of Cancer/Mycosis Study Group (EORTC/MSG) criteria. Results: A total of 15 patients was diagnosed with proven (1 case), probable (8 cases), or possible (6 cases) hospital-acquired IA during period 1. In period 2, 14 patients were diagnosed with either proven (1 case), probable (10 cases), or possible (3 cases) hospital-acquired IA. Total mold and Aspergillus spp. spore levels in the air tended to be higher in period 1 (p = 0.06 and 0.48, respectively). The incidence rate of all IA by the EORTC/MSG criteria was significantly higher in period 1 than in period 2 (1.891 vs. 0.930 per 1000 person-days, p = 0.05). Conclusions: Airborne fungal spore levels tended to be higher during the period with heavier construction works involving demolition and excavation, during which the incidence of IA was significantly higher as well. We recommend monitoring airborne fungal spore levels during construction periods in hospitals with immunocompromised patients. Subsequently, the effect of airborne fungal spore level monitoring in reducing hospital-acquired IA should be evaluated.

Seroprevalence of Measles in Healthcare Workers in South Korea.

There are only limited data regarding the seroprevalence of measles of healthcare workers (HCWs) in Korea. We evaluated the seroprevalence of measles in HCWs in a tertiary care hospital in Korea. A total of 7,411 HCWs born from 1952 to 1995 underwent antibody test. The overall seropositivity of measles was 73% (95% confidence interval, 72 - 74). The seropositivity of measles sharply declined from 85% in the 1986 birth cohort to 42% in the 1995 birth cohort, thus signifying pockets of under-immunity. Our data warrant the need for routine antibody tests, followed by measles vaccination or routine measles vaccination in young Korean HCWs.

Laboratory-based surveillance of hospital-acquired respiratory virus infection in a tertiary care hospital.

Of 7,772 laboratory-confirmed cases of respiratory viral infection among hospitalized patients, 22.8% were categorized as having hospital-acquired infection. The overall incidence of hospital-acquired respiratory viral infection was 3.9 (95% confidence interval, 3.7-4.1) cases per 1,000 admitted patients. Rhinovirus was the most common virus (30.3%), followed by influenza virus (17.6%) and parainfluenza virus (15.6%).

Clearance Rate of Carbapenemase-Producing Enterobacteriaceae Carriage Among Hospitalized Patients.

During the past decade, carbapenemase-producing Enterobacteriaceae (CPE) has emerged and spread across the world. 1 The major carbapenemase enzymes currently being reported are KPC, NDM-1, VIM, IMP, and OXA. 2 Because carbapenemase can be effectively transmitted via mobile genetic elements, and current therapeutic options for CPE infections are extremely limited, CPE may be one of the most serious contemporary threats to public health. However, very little is known about the characteristics of CPE carriage during hospitalization. The aims of this study were to investigate the clearance rate of CPE carriage and determine the number of consecutive negative cultures required to confirm CPE clearance. We also examined CPE transmission among hospitalized patients.

Assessment of the appropriateness of hand surface coverage for health care workers according to World Health Organization hand hygiene guidelines.

We monitored hand surface coverage technique in health care workers in a tertiary care hospital using a 5-item hand hygiene assessment tool based on World Health Organization guidelines. Overall hand hygiene compliance was 86.7% (4,300/4,960). Appropriate hand surface coverage was observed in only 7.9% (182/2,297) of hand hygiene procedures.