Erratum: Correction of Funding in the Article "Rates of COVID-19 Infection Among Healthcare Workers in Designated COVID-19 Wards and General Wards".

This corrects the article on p. e308 in vol. 37, PMID: 36345254.

Usefulness of universal SARS-CoV-2 PCR testing for inpatients and their caregivers during the omicron era.

Background: Since January 2022, the Omicron variant has become the dominant strain in South Korea, and COVID-19 cases among hospitalized patients and their guardians or caregivers have increased. We evaluated the usefulness of universal periodic screening for SARS-CoV-2 in patients and resident caregivers in a South Korean tertiary care hospital. Methods: We evaluated the reason for testing in COVID-19 confirmed patients and resident caregivers during their hospitalization from March 3 to 31, 2022. The rate of positive PCR universal testing in hospital (or residency) (HD) on days 3 and 7 in asymptomatic patients and caregivers were evaluated. The test for SARS-CoV-2 was done by RT-PCR. Results: During the study period, 677 patients were diagnosed with COVID-19. The reasons for testing were the symptoms (226 (33%)), pre-admission test (183 (27%)), exposure to COVID-19 (124 (18%)), universal testing on HD 3 (94 (14%)), and that on HD 7 (34 (5%)). Caregivers (n = 340) were tested during their residency due to exposure to COVID-19 cases, 103 (30%); universal testing on HD 3, 90 (26%); symptom development, 46 (14%); pre-stay, 39 (11%); and universal testing on HD 7, 29 (9%). The positive test rates of inpatients and caregivers on HD 3 and HD 7 were as follows: 1.4% (93/6553) and 2.1% (55/2646) in inpatients, and 1.3% (79/5989) and 1.7% (35/2106) in caregivers, respectively. Conclusions: Universal testing, regardless of symptom or epidemiologic link, is useful for detecting pre-symptomatic and asymptomatic COVID-19 cases among hospitalized patients and caregivers and preventing a nosocomial outbreak during the Omicron era.

Rates of COVID-19 Infection Among Healthcare Workers in Designated COVID-19 Wards and General Wards.

BACKGROUND: To evaluate the effects of isolating coronavirus disease 2019 (COVID-19) patients in general wards, we compared the rates of COVID-19 infection in nurses and nursing assistants working in COVID-19 designated wards and in general wards of our hospital from 1 October 2021 to 21 April 2022. METHODS: This study was conducted in a 2,700-bed tertiary care hospital in Seoul, Korea. Designated wards comprised single, negative pressure rooms and a 100% outdoor air system. RESULTS: During the study period, a total of 2,698 nurses and nursing assistants were employed at our hospital, of whom 310 (11%) were working in the designated wards, and the remaining 2,388 (89%) in the general wards, and among whom 1,158 (43%) were diagnosed with COVID-19. The healthcare workers (HCWs) in the designated wards were less frequently diagnosed with COVID-19 than those in the general wards (31% vs. 45%, P < 0.001). During the period before patients with COVID-19 were isolated in general wards, and during the period after these cases were isolated in general ward, HCWs in designated wards were less frequently infected with the virus than those in general wards (7% vs. 11%, P = 0.039; and 23% vs. 33%, P < 0.001, respectively). CONCLUSION: HCWs in designated wards have a lower rate of contracting COVID-19 than those in general wards. A lack of exposure to undiagnosed cases and their caregivers, greater care with social distancing outside the hospital, higher rates of 3-dose vaccinations, and the use of isolation rooms with negative pressure may be associated with this finding.

Evaluation of In-Hospital Cluster of COVID-19 Associated With a Patient With Prolonged Viral Shedding Using Whole-Genome Sequencing.

BACKGROUND: Patients with hematologic malignancies may produce replication-competent virus beyond 20 days of SARS-CoV-2 infection. However, data regarding the transmission of SARS-CoV-2 from patients with prolonged viral shedding is limited. METHODS: In May 2022, four additional cases of COVID-19 were reported in a hematologic ward at a tertiary care hospital in South Korea, after an 8-week isolation of a patient with prolonged viral shedding. We performed whole-genome sequencing (WGS) of SARS-CoV-2 to evaluate the possibility of post-isolation transmission from this prolonged viral shedding. RESULTS: A patient (case 1) with acute myeloid leukemia was released from isolation 54 days after the diagnosis of COVID-19 based on rising Ct value of up to 29.3, and moved to a six-patient room. On days 10 and 11 post-isolation, his doctor (case 2) and 2 patients who were his roommates (case 3, 4) had positive SARS-CoV-2 PCR results. Additionally, 16 days post-isolation, another patient (case 5) in a remote room had positive SARS-CoV-2 PCR result. All the three patients were hospitalized for ≥ 14 days when they were diagnosed with SARS-CoV-2 infection. Except for case 3, the remaining 4 cases were available for WGS, which revealed that case 1 exhibited a 7 nucleotides difference in comparison to cases 4 and 5 and case 2 displayed a 20 nucleotides difference compared with case 1, while sequences of cases 4 and 5 were identical. CONCLUSIONS: Despite the possibility of transmission from the patient with prolonged viral shedding, no evidence of the transmission of SARS-CoV-2 from the patient with prolonged positive RT-PCR using WGS was found.

Two Case Reports of Life-Threatening Croup Caused by the SARS-CoV-2 Omicron BA.2 Variant in Pediatric Patients.

Croup is a common upper airway infection characterized by a barking cough, stridor, and hoarseness. It is usually caused by viral infection. A small number of croup caused by coronavirus disease 2019 (COVID-19) has been reported in children before the omicron variant surge. Previously reported cases indicated that croup caused by COVID-19 can be treated in the same manner as those with other viral causes. We describe two cases (9-month-old girl and 11-month-old boy) of previously healthy infants who presented with a barking cough and chest retraction and required endotracheal intubation and cardiopulmonary resuscitation. Despite receiving dexamethasone and nebulized racemic epinephrine (NRE) treatment for croup in the emergency department, these patients still developed acute respiratory failure. Reverse transcription polymerase chain reaction (RT-PCR) of nasopharyngeal samples revealed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron BA.2 variant (Stealth omicron) and no other common respiratory viral pathogens. Both patients were treated with mechanical ventilation, dexamethasone, and NRE in the pediatric intensive care unit. The duration of intubation was 112 hours and 80 hours, respectively. Both patients were discharged without complications. To the best of our knowledge, this is the first report of life-threatening croup produced by the omicron BA.2 variant and confirmed by RT-PCR. We suggest that this SARS-CoV-2 variant may cause severe croup that may not improve with conventional treatment, even in children without underlying diseases.

Mixed Reality-Based Interaction between Human and Virtual Cat for Mental Stress Management.

Human-animal interaction (HAI) has been observed to effectively reduce stress and induce positive emotions owing to the process of directly petting and interacting with animals. Interaction with virtual animals has recently emerged as an alternative due to the limitations in general physical interactions, both due to the COVID-19 pandemic and, more generally, due to the difficulties involved in providing adequate care for animals. This study proposes mixed reality (MR)-based human-animal interaction content along with presenting the experimental verification of its effect on the reduction of mental stress. A mental arithmetic task was employed to induce acute mental stress, which was followed by either MR content, in which a participant interacted with virtual animals via gestures and voice commands, or a slide show of animal images. During the experiment, an electrocardiogram (ECG) was continuously recorded with a patch-type, wireless ECG sensor on the chest of the subject, and their psychological state was evaluated with the help of questionnaires after each task. The findings of the study demonstrate that the MR-based interaction with virtual animals significantly reduces mental stress and induces positive emotions. We expect that this study could provide a basis for the widespread use of MR-based content in the field of mental health.

Adverse Events with the Pfizer-BioNTech COVID-19 Vaccine among Korean Healthcare Workers.

The Pfizer-BioNTech COVID-19 vaccine has shown excellent clinical effectiveness; however, adverse events of the vaccine remain a concern in Korea. We surveyed adverse events in 2498 healthcare workers vaccinated with the Pfizer-BioNTech COVID-19 vaccine at a university hospital. The survey was conducted using a diary card for 7 days following each injection. The questionnaire response rate was 75.1% (1876/2498) for the first dose and 73.8% (1840/2493) for the second dose. Among local reactions, pain was the most commonly reported (84.9% after the first dose and 90.4% after the second dose). After the second dose, two people visited the emergency room due to severe local pain, but no hospitalization or skin necrosis occurred. Among systemic reactions, fatigue was most frequently reported (52.8% after the first dose and 77.0% after the second dose), followed by myalgia (49.0% and 76.1%), headache (28.7% and 59.2%), chills (16.7% and 54.0%), and arthralgia (11.4% and 39.2%). One or more critical adverse events occurred in 0.2% and 0.7% of the vaccinees. Except for urticaria, more adverse events were reported after the second dose than after the first dose. In the future, adverse events should be investigated in older adults, and a future study with a longer observation period should be conducted.

Adverse Reactions Following the First Dose of ChAdOx1 nCoV-19 Vaccine and BNT162b2 Vaccine for Healthcare Workers in South Korea.

BACKGROUND: We performed a prospective survey on the adverse reactions following the first dose of two types of vaccines against coronavirus disease 2019 (COVID-19) in healthcare workers (HCWs) in South Korea. METHODS: HCWs at a tertiary referral hospital in Seoul, South Korea, received a chimpanzee adenovirus-vectored vaccine (ChAdOx1 nCoV-19) or an mRNA-based vaccine (BNT162b2) between March 5 and March 26, 2021. The HCWs were asked to report adverse reactions through a mobile self-report questionnaire for three days after vaccination. RESULTS: A total of 7,625 HCWs received the first dose of ChAdOx1 or BNT162b2 vaccine during the study period. Of them, 5,866 (76.9%) HCWs (ChAdOx1, n = 5,589 [95.3%]; BNT162b2, n = 277 [4.7%]) participated at least once in the survey, of whom 77% were female and 86% were younger than 50 years. The overall adverse reaction rate was 93% in the ChAdOx1 group and 80% in the BNT162b2 group (P < 0.001). Both local and systemic reactions were more commonly reported in the ChAdOx1 group, and the difference was larger in systemic reactions such as fever and fatigue. In the ChAdOx1 group, the incidence of adverse reactions was significantly higher in females and those in the younger age groups, while the BNT162b2 group showed such difference according to age. CONCLUSION: In our prospective survey, vaccine-associated adverse reactions were more commonly reported in the ChAdOx1 group than in the BNT162b2 group. Females and younger age groups experienced vaccine-associated adverse reactions more frequently.