Ventilation strategies based on an aerodynamic analysis during a large-scale SARS-CoV-2 outbreak in an acute-care hospital.

BACKGROUND: This study aimed to investigate ventilation strategies to prevent nosocomial transmission of coronavirus disease 2019 (COVID-19). METHODS: We conducted a retrospective epidemiological investigation of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak in a teaching hospital (February-March 2021). The largest outbreak ward was studied, and measurements were taken to determine the pressure difference and air change per hour (ACH) of the rooms. Airflow dynamics were assessed using an oil droplet generator, indoor air quality sensor, and particle image velocimetry in the index patient's room, corridor, and opposite rooms, by varying the opening and closing of windows and doors. RESULTS: During the outbreak, 283 COVID-19 cases were identified. The SARS-CoV-2 spread occurred sequentially from the index room to the nearest room, especially the opposite. The aerodynamic study demonstrated that droplet-like particles in the index room diffused through the corridor and the opposite room through the opening door. The mean ACH of the rooms was 1.44; the air supply volume was 15.9% larger than the exhaust volume, forming a positive pressure. Closing the door prevented diffusion between adjacent rooms facing each other, and natural ventilation reduced the concentration of particles within the ward and minimised their spread to adjacent rooms. CONCLUSIONS: Spread of droplet-like particles between rooms could be attributed to the pressure difference between the rooms and corridor. To prevent spread of SARS-CoV-2 between rooms, increasing the ACH in the room by maximising ventilation and minimising the positive pressure through supply/exhaust control and closing the room door are essential.

Correlates of burnout among healthcare workers during the COVID-19 pandemic in South Korea.

Burnout is a form of negative emotional and physical response to job stress. This study aimed to investigate the prevalence of burnout among healthcare workers responding to the coronavirus disease 2019 (COVID-19) outbreak in Korea and to explore correlates of burnout among healthcare workers. A nationwide questionnaire-based survey was conducted from December 1, 2020, to January 29, 2021 on 1425 healthcare workers who worked in one of the 16 healthcare facilities designated for COVID-19 care, in public health centers, or as paramedics in Korea. Burnout was assessed using 16 Korean-adapted items based on the Oldenburg Burnout Inventory (OLBI). Data were collected using a structured questionnaire and analyzed using the R version 4.1.1 software program. OLBI results indicate clinically exhaustion in 84.5% (1204/1425) and clinically disengagement in 91.1% (1298/1425), and 77.3% (1102/1425) met the score criteria for both the exhaustion and disengagement subscales for burnout. Burnout rate was significantly increased in the group with chronic fatigue symptoms (Fatigue Severity Scale ≥ 3.22) after the outbreak of COVID-19 (OR, 3.94; 95% CI 2.80-5.56), in the female group (OR, 2.05; 95% CI 1.46-2.86), in the group with physical symptoms (Patient Health Questionnaire-15 ≥ 10) after the outbreak of COVID-19 (OR, 2.03; 95% CI 1.14-3.60), in the group with a higher Global Assessment of Recent Stress scale (OR, 1.71; 95% CI 1.46-2.01), in the group with post-traumatic stress symptoms (Primary Care Post-Traumatic Stress Disorder-5 ≥ 2) (OR, 1.47; 95% CI 1.08-2.01), and in the younger age group(OR, 1.45; 95% CI 1.22-1.72). The chronic fatigue symptoms were correlated with cumulative days of care (OR, 1.18; 95% CI 1.02-1.37). The physical symptoms were correlated with average contact hours with COVID-19 patients per day (OR, 1.34; 95% CI 1.17-1.54), and cumulative days of care (OR, 1.21; 95% CI 1.06-1.38). Most Korean healthcare workers suffered from burnout related to excessive workload during the COVID-19 pandemic. During a widespread health crisis like COVID-19, it is necessary to regularly check the burnout status in healthcare workers and reduce their excessive workload by supplementing the workforce and providing appropriate working hours sufficient rest hours.

Guidelines for Infection Control and Burnout Prevention in Healthcare Workers Responding to COVID-19.

During the coronavirus disease 2019 (COVID-19) pandemic, frontline healthcare workers (HCWs) suffered more distress from the possibility of contracting the virus, quarantine, social stigma, and prejudice against their families. Many studies have investigated the impact of the pandemic on HCWs; however, studies or guidelines presenting strategies to overcome these challenges are lacking. As part of a 2020 research project supported by the Ministry of Health and Welfare, titled "Health impact assessment of healthcare workers undertaking coronavirus disease 2019 treatment and management in Korea: Identifying problems and researching effective solutions" (HC20C0003), we created guidelines to respond to serious problems posed by infection control. and burnout among HCWs during COVID-19 response measures throughout the extended pandemic period. We formulated the guidelines by means of a systematic review and collated them with the latest literature. The guidelines will highlight the gravity and impact of infection control and burnout among HCWs responding to COVID-19 and include potential prevention strategies, and they can be used as a reference in the event of another emerging infectious disease outbreak in the future.

Expert Consensus on Measures to Promote Physical and Psychological Health among COVID-19-Related Healthcare Workers in Korea using Delphi Technique.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has caused health problems and distress among healthcare workers (HCWs), so supportive measures to promote their health and relieve distress are needed. MATERIALS AND METHODS: We conducted two rounds of Delphi surveys with 20 COVID-19-related frontline healthcare professionals and public officials. The surveys evaluated means of supporting HCWs' health by improving health care systems and working environments in terms of effectiveness and urgency. The validity of the measures was assessed by calculating the content validity ratio. RESULTS: The top-priority measures to support HCWs were "secure isolation units capable of treating severe cases" in the facility infrastructure category, "secure nursing staff dedicated for patients in the intensive care units" in the personnel infrastructure category, "improve communication between central office and frontline field" in the cooperation system category, "support personal protective equipment and infection control supplies" in the aid supplies category, and "realization of hazard pay" in the physical/mental health and compensation category. CONCLUSION: There was consensus among the experts on the validity and priorities of policies in the facility, personnel, cooperation, supplies, and compensation categories regarding measures to promote COVID-19 related HCWs' health.

A SARS-CoV-2 outbreak associated with vaccine breakthrough in an acute care hospital.

BACKGROUND: We aimed to analyze an outbreak caused by a vaccine breakthrough infection in a hospital with an active infection control program where 91.9% of health care workers were vaccinated. METHODS: We investigated a SARS-CoV-2 outbreak between September 9 and October 2, 2021, in a referral teaching hospital in Korea. We retrospectively collected data on demographics, vaccination history, transmission, and clinical features of confirmed coronavirus disease 2019 (COVID-19) in patients, health care workers, and caregivers. RESULTS: During the outbreak, 94 individuals tested positive for SARS-CoV-2 using reverse transcription-polymerase chain reaction testing. There were infections in 61 health care workers, 18 patients, and 15 caregivers; 74.5% (70/94) were vaccine breakthrough infections. Most transmissions appeared to be caused by three index cases, which accounted for 86.2% (81/94) of transmissions. Forty-seven (58.0%, 47/81) cases were associated with the hospital staff cafeteria and offices located in the basement. Among health care workers and caregivers, only one required oxygen supplementation. In contrast, among patients, there were four fatal cases (22.2%, 4/18), 3 of which were unvaccinated. CONCLUSIONS: Superspreading infection among fully vaccinated individuals occurred in an acute care hospital while the delta variant was dominant. Given the potential for severe complications, as this outbreak demonstrated, preventive measures including adequate ventilation should be emphasized to minimize transmission in hospitals.

Workload of Healthcare Workers During the COVID-19 Outbreak in Korea: A Nationwide Survey.

BACKGROUND: As the coronavirus disease 2019 (COVID-19) pandemic is ongoing, heavy workload of healthcare workers (HCWs) is a concern. This study investigated the workload of HCWs responding to the COVID-19 outbreak in South Korea. METHODS: A nationwide cross-sectional survey was conducted from September 16 to October 15, 2020, involving 16 healthcare facilities (4 public medical centers, 12 tertiary-care hospitals) that provide treatment for COVID-19 patients. RESULTS: Public medical centers provided the majority (69.4%) of total hospital beds for COVID-19 patients (n = 611), on the other hand, tertiary care hospitals provided the majority (78.9%) of critical care beds (n = 57). The number of beds per doctor (median [IQR]) in public medical centers was higher than in tertiary care hospitals (20.2 [13.0, 29.4] versus 3.0 [1.3, 6.6], P = 0.006). Infectious Diseases physicians are mostly (80%) involved among attending physicians. The number of nurses per patient (median [interquartile range, IQR]) in tertiary-care hospitals was higher than in public medical centers (4.6 [3.4-5] vs. 1.1 [0.8-2.1], P = 0.089). The median number of nurses per patient for COVID-19 patients was higher than the highest national standard in South Korea (3.8 vs. 2 for critical care). All participating healthcare facilities were also operating screening centers, for which a median of 2 doctors, 5 nurses, and 2 administrating staff were necessary. CONCLUSION: As the severity of COVID-19 patients increases, the number of HCWs required increases. Because the workload of HCWs responding to the COVID-19 outbreak is much greater than other situations, a workforce management plan regarding this perspective is required to prevent burnout of HCWs.

SARS-CoV-2-Specific Antibody and T Cell Response Kinetics According to Symptom Severity.

Data on the longevity of humoral and cell-mediated immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with coronavirus disease 2019 (COVID-19) are limited. We evaluated the detailed kinetics of antibody and T-cell responses at the acute, convalescent, and post-convalescent phases in COVID-19 patients with a wide range of severity. We enrolled patients with COVID-19 prospectively from four hospitals and one community treatment center between February 2020 and January 2021. symptom severity was classified as mild, moderate, or severe/critical. Patient blood samples were collected at 1 week (acute), 1 month (convalescent), and 2 months after symptom onset (post-convalescent). Human SARS-CoV-2 IgG and IgM antibodies were measured using in-house-developed ELISA. The SARS-CoV-2-specific T-cell responses against overlapping peptides of spike proteins and nucleoprotein were measured by interferon-γ enzyme-linked immunospot assays. Twenty-five COVID-19 patients were analyzed (mild, n = 5; moderate, n = 9; severe/critical, n = 11). IgM and IgG antibody responses peaked at 1 month after symptom onset and decreased at 2 months. IgG response levels were significantly greater in the severe/critical group compared with other groups. Interferon-γ-producing T-cell responses increased between 1 week and 1 month after symptom onset, and had a trend toward decreasing at 2 months, but did not show significant differences according to severity. Our data indicate that SARS-CoV-2-specific antibody responses were greater in those with severe symptoms and waned after reaching a peak around 1 month after symptom onset. However, SARS-CoV-2-specific T-cell responses were not significantly different according to symptom severity, and decreased slowly during the post-convalescent phase.

Risk factors for isolation of multi-drug resistant organisms in coronavirus disease 2019 pneumonia: A multicenter study.

OBJECTIVES: Superimposed multi-drug resistant organisms (MDROs) co-infection can be associated with worse outcomes in patients with severe coronavirus disease 2019 (COVID-19), even if these patients were managed with strict airborne and contact precautions. Identifying risk factors for isolation of MDROs is critical to COVID-19 treatment. METHODS: All eligible adult patients with confirmed COVID-19 pneumonia from 10 hospitals in the Republic of Korea between February 2020 and May 2020 were retrospectively enrolled. Using this cohort, epidemiology and risk factors for isolation of MDROs were evaluated. RESULTS: Of 152 patients, 47 with microbial culture results were included. Twenty isolates of MDROs from 13 (28%) patients were cultured. Stenotrophomonas maltophilia (5 isolates) was the most common MDRO, followed by methicillin-resistant staphylococcus aureus (4 isolates). MDROs were mostly isolated from sputum samples (80%, 16/20). The median time from hospitalization to MDRO isolation was 28 days (interquartile range, 18-38 days). In-hospital mortality was higher in patients with MDRO isolation (62% vs 15%; P = .001). Use of systemic corticosteroids after diagnosis of COVID-19 (adjusted odds ratio [aOR]: 15.07; 95% confidence interval [CI]: 2.34-97.01; P = .004) and long-term care facility (LTCF) stay before diagnosis of COVID-19 (aOR: 6.09; 95% CI: 1.02-36.49; P = .048) were associated with MDRO isolation. CONCLUSIONS: MDROs were isolated from 28% of COVID-19 pneumonia patients with culture data and 8.6% of the entire cohort. Previous LTCF stay and adjunctive corticosteroid use were risk factors for the isolation of MDROs. Strict infection prevention strategies may be needed in these COVID-19 patients with risk factors.

Impacts of Side Effects to BNT162b2 and the First Dose of ChAdOx1 Anti-SARS-CoV-2 Vaccination on Work Productivity, the Need for Medical Attention, and Vaccine Acceptance: A Multicenter Survey on Healthcare Workers in Referral Teaching Hospitals in the Republic of Korea.

To establish a successful anti-SARS-CoV-2 vaccination strategy, it is necessary to take possible tradeoffs into account. We conducted a survey on vaccinated healthcare workers (HCWs) inthree referral teaching hospitals in the Republic of Korea. We investigated the frequency of vaccination side effects (SEs), the impact on their work productivity, the need for medical attention, and vaccine acceptance. Three groups of HCWs were surveyed: 1406 who had received the first dose of BNT162b2 (BNT162b2#1), 1168 who had received the second dose of BNT162b2 (BNT162b2#2), and 1679 who had received the first dose of ChAdOx1 (ChAdOx1#1). More SEs and impact on work productivity were reported in ChAdOx1#1 than in the other two groups. However, among individuals aged ≥40 years, no significant difference of absence from work was found between ChAdOx1#1 and BN162b2#2 (4.4%, 31/699 vs. 3.0%, 12/405; p = 0.26), and none were hospitalized. Older HCWs in ChAdOx1#1 showed intention to receive the second dose of the vaccine. Although the incidence of SEs and their impacts were greater after the first dose of ChAdOx1 than BNT162b2 in young people, significant impact of SEs seemed to be rare in individuals aged ≥40 years, regardless of the vaccine they received.

What should we prepare for the next coronavirus disease 2019 outbreak? A survey on the opinions of infectious diseases specialists in South Korea.

BACKGROUND/AIMS: This study aimed to collect information on the opinions of Korean infectious disease (ID) experts on coronavirus disease 2019 (COVID-19) and related issues in preparation for a future outbreak. METHODS: A survey was conducted over the course of 5 days (from April 21 to 25, 2020), targeting all adult ID specialists currently in the medical field in South Korea (n = 265). An online-based survey was forwarded via text message and e-mail. Only one response was accepted from each participant. RESULTS: Of these 265 ID specialists gotten to, 132 (49.8%) responded. The highest proportion of the respondents envisaged the current COVID-19 outbreak to end after December 2020 (47.7% for the domestic Korean outbreak and 70.5% for the global pandemic); moreover, 60.7% of them stated that a second nationwide wave is likely to occur between September and December 2020 in South Korea. N95 respirators were considered to be the most important item in hospitals in preparation for a second wave. The most important policy to be implemented at the national level was securing national hospitals designated for the treatment of ID (67.4%). CONCLUSION: ID experts in South Korea believe that the COVID-19 pandemic may not be easily controlled and that a second nationwide wave is likely to occur in South Korea. Our results indicate that Korean ID specialists believe that a high level of preparation is needed in various aspects, including the procurement of personal protective equipment, to respond efficiently to a second outbreak.

Psychological distress among infectious disease physicians during the response to the COVID-19 outbreak in the Republic of Korea.

BACKGROUND: This study aimed to investigate psychological distress among infectious disease (ID) physicians during the coronavirus disease 2019 (COVID-19) outbreak in the Republic of Korea. METHODS: Using an online-based survey link sent via text message and email, we conducted a survey from April 21 to 25, 2020, targeting all ID physicians currently working in ID (n = 265). The questionnaire was based on the Maslach Burnout Inventory-Human Services Survey and the Depression, Anxiety, and Stress Scales, and information was collected on factors protecting against psychological distress and difficulties in relation to COVID-19. RESULTS: Of 265 ID physicians, 115 (43.3%) responded, showing burnout (97, 90.4%), depression (20, 17.4%), anxiety (23, 20.0%), and stress (5, 4.3%). There were no differences in terms of distress between ID physicians who were directly involved in the care of patients with COVID-19 or not. Greater than 50% of physicians valued their work and felt recognized by others, whereas < 10% indicated that sufficient human and financial support and private time had been provided during the outbreak. The most challenging issues concerned a lack of attending physicians caring for COVID-19 patients or infection control practitioners, a shortage of personal protective equipment or airborne infection isolation rooms, pressure for research, and lack of guidelines for COVID-19 management. CONCLUSIONS: During the COVID-19 outbreak in the Republic of Korea, most respondents reported psychological distress. Preparing strategies to secure human resources are crucial to prepare effectively for future epidemics and pandemics.

Factors of Severity in Patients with COVID-19: Cytokine/Chemokine Concentrations, Viral Load, and Antibody Responses.

The severity of COVID-19 ranges from mild to critical diseases. However, limited data have been published on the detailed kinetics of viral load and host immune response throughout the disease course depending on disease severity. In this study, we comprehensively analyzed viral load, antibody responses to SARS-CoV-2, and cytokines/chemokines during the disease course, and identified the factors related to severity. Nasopharyngeal (NP) and plasma specimens were obtained from 31 patients with COVID-19 during hospitalization. Viral RNA in NP specimens was quantified by reverse transcription-PCR. Anti-SARS-CoV-2 antibodies and cytokines/chemokines in plasma specimens were analyzed by ELISA and cytometric bead array. The viral load in patients with COVID-19 peaked at the early stage of the disease and continuously decreased. Severe and critical cases showed higher viral load and prolonged viral shedding than asymptomatic and mild cases. Whereas plasma IgG was gradually increased and maintained during hospitalization, plasma IgM peaked at 3 weeks after symptom onset and dissipated. The antibody response in severe and critical cases was slightly delayed but stronger than those in others. High levels of interferon (IFN)-α, IFN-γ-induced protein-10, monokine induced by IFN-γ, and interleukin-6 at 5-10 days from symptom onset were associated with the severity of COVID-19. Our data indicate that high viral load in the respiratory tract and excessive production of cytokines and chemokines between 1 and 2 weeks from the symptom onset were significantly associated with the severity of COVID-19.

Effectiveness of surgical, KF94, and N95 respirator masks in blocking SARS-CoV-2: a controlled comparison in 7 patients.

BACKGROUND: Data on the filtration efficacies of various masks against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited. We thus evaluate the effectiveness of the surgical mask, the N95 respirator mask, and its equivalent (KF94 mask) in filtering SARS-CoV-2. METHODS: Patients hospitalised with SARS-CoV-2 infection were instructed to cough five times each while wearing (1) no mask, (2) surgical mask, (3) KF94 mask, and (4) N95 mask. The coughs were separated by 20-second intervals, and the patients were rested for at least 5 min between each setting. SARS-CoV-2 viral loads in patient samples (i.e. nasopharyngeal swabs and saliva), petri dishes placed in front of the patients during coughing, and swabs from the outer and inner surfaces of the masks were analysed with PCR. RESULTS: A total of 7 patients with SARS-CoV-2 infection participated in the mask test. SARS-CoV-2 was detected on the petri dishes after coughing in 3 out of 7 cases with the surgical mask or no mask. Viral particles were not found in the petri dishes after coughing while wearing the N95 mask or the KF94 mask. While viral particles were detected in both the inner and outer surfaces of the surgical masks, those were detected only in the inner surfaces of the N95 and K94 masks. CONCLUSION: Surgical masks were less effective in filtering viral particles from coughing patients with SARS-CoV-2 infection. N95 masks and its equivalents efficiently blocked SARS-CoV-2 particles from coughing patients.

Clinical Course and Molecular Viral Shedding Among Asymptomatic and Symptomatic Patients With SARS-CoV-2 Infection in a Community Treatment Center in the Republic of Korea.

IMPORTANCE: There is limited information about the clinical course and viral load in asymptomatic patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). OBJECTIVE: To quantitatively describe SARS-CoV-2 molecular viral shedding in asymptomatic and symptomatic patients. DESIGN, SETTING, AND PARTICIPANTS: A retrospective evaluation was conducted for a cohort of 303 symptomatic and asymptomatic patients with SARS-CoV-2 infection between March 6 and March 26, 2020. Participants were isolated in a community treatment center in Cheonan, Republic of Korea. MAIN OUTCOMES AND MEASURES: Epidemiologic, demographic, and laboratory data were collected and analyzed. Attending health care personnel carefully identified patients' symptoms during isolation. The decision to release an individual from isolation was based on the results of reverse transcription-polymerase chain reaction (RT-PCR) assay from upper respiratory tract specimens (nasopharynx and oropharynx swab) and lower respiratory tract specimens (sputum) for SARS-CoV-2. This testing was performed on days 8, 9, 15, and 16 of isolation. On days 10, 17, 18, and 19, RT-PCR assays from the upper or lower respiratory tract were performed at physician discretion. Cycle threshold (Ct) values in RT-PCR for SARS-CoV-2 detection were determined in both asymptomatic and symptomatic patients. RESULTS: Of the 303 patients with SARS-CoV-2 infection, the median (interquartile range) age was 25 (22-36) years, and 201 (66.3%) were women. Only 12 (3.9%) patients had comorbidities (10 had hypertension, 1 had cancer, and 1 had asthma). Among the 303 patients with SARS-CoV-2 infection, 193 (63.7%) were symptomatic at the time of isolation. Of the 110 (36.3%) asymptomatic patients, 21 (19.1%) developed symptoms during isolation. The median (interquartile range) interval of time from detection of SARS-CoV-2 to symptom onset in presymptomatic patients was 15 (13-20) days. The proportions of participants with a negative conversion at day 14 and day 21 from diagnosis were 33.7% and 75.2%, respectively, in asymptomatic patients and 29.6% and 69.9%, respectively, in symptomatic patients (including presymptomatic patients). The median (SE) time from diagnosis to the first negative conversion was 17 (1.07) days for asymptomatic patients and 19.5 (0.63) days for symptomatic (including presymptomatic) patients (P = .07). The Ct values for the envelope (env) gene from lower respiratory tract specimens showed that viral loads in asymptomatic patients from diagnosis to discharge tended to decrease more slowly in the time interaction trend than those in symptomatic (including presymptomatic) patients (ß = -0.065 [SE, 0.023]; P = .005). CONCLUSIONS AND RELEVANCE: In this cohort study of symptomatic and asymptomatic patients with SARS-CoV-2 infection who were isolated in a community treatment center in Cheonan, Republic of Korea, the Ct values in asymptomatic patients were similar to those in symptomatic patients. Isolation of asymptomatic patients may be necessary to control the spread of SARS-CoV-2.

Persistent severe acute respiratory syndrome coronavirus 2 detection after resolution of coronavirus disease 2019-associated symptoms/signs.

There are limited data on the duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in respiratory specimens after resolution of coronavirus disease 2019 (COVID-19)-associated symptoms/signs. We determined duration of SARS-CoV-2 virus shedding in symptomatic patients after remission of symptoms. We investigated the duration of SARS-CoV-2 RNA detection using real-time reverse transcriptase polymerase chain reaction for SARS-CoV-2 in nasopharyngeal/oropharyngeal swabs or sputum or saliva. Six patients were included in the final analysis. The median (range) duration of SARS-CoV-2 viral detection after hospitalization was 34 days (22 to 67). After resolution of symptoms/signs, SARS-CoV-2 RNA was detected for median (range) of 26 days (9 to 48). Among the six patients, one had persistent detection of SARS-CoV-2 RNA until day 67 of hospitalization, which was 30 days after symptom resolution. This case represents the longest duration of SARS-CoV-2 detection, and highlights the need for long-term follow up of COVID-19 patients despite resolution of symptoms to confirm SARS-CoV-2 clearance.