Nosocomial Outbreak by Delta Variant From a Fully Vaccinated Patient

Background@#The potential for a nosocomial outbreak of coronavirus disease 2019 (COVID-19) from a fully vaccinated individual is largely unknown. @*Methods@#In October 2021, during the time when the delta variant was dominant, a nosocomial outbreak of COVID-19 occurred in two wards in a tertiary care hospital in Seoul, Korea. We performed airflow investigations and whole-genome sequencing (WGS) of the virus. @*Results@#The index patient developed symptoms 1 day after admission, and was diagnosed with COVID-19 on day 4 post-admission. He was fully vaccinated (ChAdOx1 nCoV-19) 2 months before the diagnosis. Three inpatients and a caregiver in the same room, two inpatients in an adjacent room, two inpatients in rooms remote from the index room, and one nurse on the ward tested positive. Also, two resident doctors who stayed in an on-call room located on the same ward tested positive (although they had no close contact), as well as a caregiver who stayed on an adjacent ward, and a healthcare worker who had casual contact with this caregiver. Samples from five individuals were available for WGS, and all showed ≤ 1 single-nucleotide polymorphism difference. CCTV footage showed that the index case walked frequently in the corridors of two wards. An airflow study showed that the air from the corridor flowed into the resident on-call room, driven by an air circulator that was always turned on. @*Conclusion@#Transmission of severe acute respiratory syndrome coronavirus 2 from a fully vaccinated index occurred rapidly via the wards and on-call room. Care must be taken to not use equipment that can change the airflow.

Risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission Among Healthcare Workers Dining in Hospital Staff Cafeterias

Background@#Preventive measures are needed to reduce the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among healthcare workers (HCWs). Notably, hospital staff are usually exposed when they are unmasked. There are limited data on the risk of transmission during mealtimes at hospital staff cafeterias. We aimed to evaluate the risk of transmission in cafeterias. @*Methods@#From January 2020 through September 2021, we analyzed the risk of SARS-CoV-2 transmission through closed-circuit television and radio-frequency identification tracking and follow-up testing when 33 HCWs, who were eventually diagnosed as coronavirus disease 2019 (COVID-19), ate in staff cafeterias during the infectious period. The seats were arranged so the HCWs would sit on either side without facing each other. There were no plastic barriers installed, and HCWs were encouraged not to talk during meals. @*Results@#Three of the 119 individuals who ate at seats next (about 30 cm) to index during the period of transmission and underwent follow-up SARS-CoV-2 polymerase chain reaction tests were diagnosed with COVID-19 (2.5%; 95% confidence interval, 0.5–7.4%). Among the 98 HCWs who were investigated about talking during meals, there was a higher attack rate among those who spoke with each other than among those who did not (12.5% [3/24] vs. 0% [0/74], P = 0.013). @*Conclusion@#The risk of transmission in a hospital’s employee cafeterias is not high with sideby-side seating, especially in the absence of conversation.

Zingerone Attenuates Pi-induced Vascular Calcification via AMPK-mediated TIMP4 Expression

Objective@#Vascular calcification requires the differentiation of vascular smooth muscle cells (VSMCs) into osteoblast-like cells. This phenomenon can be enhanced by inflammation and oxidative stress. Zingerone is one of the active ingredients present in the ginger plant that has anti-inflammatory and antioxidant effects. Other functions include anti-obesity, antinausea effects. However, the functions of zingerone on vascular calcification has not yet been elucidated. This study investigated the effect of zingerone on vascular calcification and its molecular mechanism. @*Methods@#Reverse transcription-polymerase chain reaction (PCR), real-time PCR and Western blot analysis was used to measure expression levels of osteogenic marker genes and to investigate whether calcification was regulated by the expression of AMP-activated protein kinase (AMPK) and tissue inhibitor of metalloproteinase 4 (TIMP4). Alizarin red S staining was used to measure calcium deposition. Studies were carried out in VSMCs. @*Results@#Zingerone induced the expression of 2 markers of VSMCs differentiation (α-smooth muscle actin (α-SMA) and smooth muscle 22α (SM22α)) and decreased the expression of corebinding factor α-1 (CBFA1). Additionally, zingerone decreased inorganic phosphate (Pi)-induced expression of distal-less homeobox 5 and CBFA1. AMPK phosphorylation and TIMP4 expression were increased by zingerone. Importantly, zingerone protected VSMCs from calcification, and this protective effect was confirmed by increased TIMP4 via overexpression of AMPK, and inhibition of TIMP4 by Compound C. Zingerone upregulated AMPK/TIMP4 expression and recovered Pi-induced inhibition of TIMP4. @*Conclusions@#Taken together, our results show that zingerone inhibits Pi-induced vascular calcification by regulating the AMPK/TIMP4 signaling cascade in VSMCs. These results suggest that the natural product zingerone could be useful for treating vascular and metabolic diseases.

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.

Frequent Occurrence of SARS-CoV-2 Transmission among Non-close Contacts Exposed to COVID-19 Patients

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission among non-close contacts is not infrequent. We evaluated the proportion and circumstances of individuals to whom SARS-CoV-2 was transmitted without close contact with the index patient in a nosocomial outbreak in a tertiary care hospital in Korea. From March 2020 to March 2021, there were 36 secondary cases from 14 SARS-CoV-2 infected individuals. Of the 36 secondary cases, 26 (72%) had been classified as close contact and the remaining 10 (28%) were classified as non-close contact. Of the 10 non-close contact, 4 had short conversations with both individuals masked, 4 shared a space without any conversation with both masked, and the remaining 2 entered the space after the index had left. At least one quarter of SARSCoV-2 transmissions occurred among non-close contacts. The definition of close contact for SARS-CoV-2 exposure based on the mode of droplet transmission should be revised to reflect the airborne nature of SARS-CoV-2 transmission.

Nosocomial Outbreak of COVID-19 in a Hematologic Ward / 감염과화학요법

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 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.

Frequent Occurrence of SARS-CoV-2 Transmission among Non-close Contacts Exposed to COVID-19 Patients

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission among non-close contacts is not infrequent. We evaluated the proportion and circumstances of individuals to whom SARS-CoV-2 was transmitted without close contact with the index patient in a nosocomial outbreak in a tertiary care hospital in Korea. From March 2020 to March 2021, there were 36 secondary cases from 14 SARS-CoV-2 infected individuals. Of the 36 secondary cases, 26 (72%) had been classified as close contact and the remaining 10 (28%) were classified as non-close contact. Of the 10 non-close contact, 4 had short conversations with both individuals masked, 4 shared a space without any conversation with both masked, and the remaining 2 entered the space after the index had left. At least one quarter of SARSCoV-2 transmissions occurred among non-close contacts. The definition of close contact for SARS-CoV-2 exposure based on the mode of droplet transmission should be revised to reflect the airborne nature of SARS-CoV-2 transmission.

Nosocomial Outbreak of COVID-19 in a Hematologic Ward / 감염과화학요법

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.

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

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-betalactamase-1 (NDM-1) and 448 Klebsiella pneumoniae carbaepenamse (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.