Presymptomatic SARS-CoV-2 Infections and Transmission in a Skilled Nursing Facility

A visualized and bibliometric analysis of nursing research during the COVID-19 pandemic

BACKGROUND

The global spread of Coronavirus disease 2019 (COVID-19) has been increasing since December 2019. A total of 8460 publications were obtained from the Web of Science Core Collection from 2019 to 2023, providing insights into the progress of nursing research throughout the COVID-19 pandemic.

METHODS

Bibliometric analysis was conducted on these articles using CiteSpace. The analysis focused on examining the distribution of these publications in terms of space and time, distribution of authors, subject categories, distribution of topics, and cited references.

RESULTS

These results may be explained from 3 perspectives. Initially, the number of yearly publications on nursing research consistently increased during the COVID-19 pandemic. Furthermore, a co-occurrence analysis of the countries and the authors revealed that certain countries, including the United States, China, and England, have successfully implemented organized and standardized nursing models. These countries also have well-developed and established nursing research systems. Notably, academic communities in specific regions, such as the team led by MD Stefan Gravenstein, Mor Vincent, and White Elizabeth at Brown University in the United States, have emerged as leaders in this field. Furthermore, examining the papers' subject categories and topic distribution indicate that nursing during the COVID-19 pandemic has been predominantly interdisciplinary, encompassing various disciplines such as clinical medicine, essential medicine, psychology, public health management, and even telematics science.

CONCLUSION SUBSECTIONGS

Our study provided valuable insights into acquiring knowledge on nursing research during the COVID-19 pandemic, pinpointed possible partners for researchers interested in nursing, and uncovered prevalent research patterns and popular subjects.

Data-driven mathematical modeling approaches for COVID-19: A survey

In this review, we successively present the methods for phenomenological modeling of the evolution of reported and unreported cases of COVID-19, both in the exponential phase of growth and then in a complete epidemic wave. After the case of an isolated wave, we present the modeling of several successive waves separated by endemic stationary periods. Then, we treat the case of multi-compartmental models without or with age structure. Eventually, we review the literature, based on 260 articles selected in 11 sections, ranging from the medical survey of hospital cases to forecasting the dynamics of new cases in the general population. This review favors the phenomenological approach over the mechanistic approach in the choice of references and provides simulations of the evolution of the number of observed cases of COVID-19 for 10 states (California, China, France, India, Israel, Japan, New York, Peru, Spain and United Kingdom).

Opportunities for Enhanced Public Health Surveillance via Molecular Detection and Sequencing of Diverse Respiratory Viruses From Self-collected SARS-CoV-2 Antigen Test Swabs

We sequenced and genotyped severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza, adenovirus, and respiratory syncytial virus, among other pathogens, from residual anterior nasal swabs self-collected for rapid SARS-CoV-2 antigen testing at the US Naval Academy. This is a key proof-of-concept for an acute respiratory infection surveillance approach, which could leverage prevalent SARS-CoV-2 antigen self-testing.

Insights into SARS-CoV-2 Surveillance among Prison Populations in Mato Grosso do Sul, Brazil, in 2022

This study examines the epidemiological and genomic characteristics, along with the transmission dynamics, of SARS-CoV-2 within prison units I and II in Campo Grande, Mato Grosso do Sul, Brazil. Conducted between May and October 2022, it reveals how the virus spreads in the confined settings of prisons, emphasizing the roles of overcrowded cells, frequent transfers, and limited healthcare access. The research involved 1927 participants (83.93% of the total prison population) and utilized nasopharyngeal swabs and RT-qPCR testing for detection. Contact tracing monitored exposure within cells. Out of 2108 samples, 66 positive cases were identified (3.13%), mostly asymptomatic (77.27%), with the majority aged 21-29 and varying vaccination statuses. Next-generation sequencing generated 28 whole genome sequences, identifying the Omicron variant (subtypes BA.2 and BA.5) with 99% average coverage. Additionally, the study seeks to determine the relationship between immunization levels and the incidence of SARS-CoV-2 cases within this enclosed population. The findings underscore the necessity of comprehensive control strategies in prisons, including rigorous screening, isolation protocols, vaccination, epidemiological monitoring, and genomic surveillance to mitigate disease transmission and protect both the incarcerated population and the broader community.

Secondary attack rate following on-site isolation of patients with suspected COVID-19 in multiple-bed rooms

The implementation of isolation precautions for patients with suspected Coronavirus Disease 2019 (COVID-19) and pending test results is resource intensive. Due to the limited availability of single-bed rooms at our institution, we isolated patients with suspected COVID-19 together with patients without suspected COVID-19 on-site in multiple-bed rooms until SARS-CoV-2-test results were available. We evaluated the likelihood of SARS-CoV-2 transmission to individuals sharing the room with patients isolated on-site. This observational study was performed at the University Hospital Basel, Switzerland, from 03/20 - 11/20. Secondary attack rates were compared between patients hospitalized in multiple-bed rooms and exposed to individuals subjected to on-site isolation precautions (on-site isolation group), and patients exposed to individuals initially not identified as having COVID-19, and not placed under isolation precautions until the diagnosis was suspected (control group). Transmission events were confirmed by whole-genome sequencing. Among 1,218 patients with suspected COVID-19, 67 (5.5%) tested positive for SARS-CoV-2. Of these, 21 were isolated on-site potentially exposing 27 patients sharing the same room. Median contact time was 12 h (interquartile range 7-18 h). SARS-CoV-2 transmission was identified in none of the patients in the on-site isolation group vs. 10/63 (15.9%) in the control group (p = 0.03). Isolation on-site of suspected COVID-19-patients in multiple-bed rooms avoided single-room occupancy and subsequent in-hospital relocation for many patients without confirmed SARS-CoV-2-infection. The absence of secondary transmission among the exposed patients in the on-site isolation group allows for assessment of the risk/benefit ratio of this strategy given the limitation of a small sample size.

Clinical Outcomes After Admission of Patients With COVID-19 to Skilled Nursing Facilities

Importance

During the COVID-19 pandemic, stabilized COVID-19-positive patients were discharged to skilled nursing facilities (SNFs) to alleviate hospital crowding. These discharges generated controversy due to fears of seeding outbreaks, but there is little empirical evidence to inform policy.

Objective

To assess the association between the admission to SNFs of COVID-19-positive patients and subsequent COVID-19 cases and death rates among residents.

Design, Setting, and Participants

This cohort study analyzed survey data from the National Healthcare Safety Network of the Centers for Disease Control and Prevention. The cohort included SNFs in the US from June 2020 to March 2021. Exposed facilities (ie, with initial admission of COVID-19-positive patients) were matched to control facilities (ie, without initial admission of COVID-19-positive patients) in the same county and with similar preadmission case counts. Data were analyzed from June 2023 to February 2024.

Exposure

The week of the first observable admission of COVID-19-positive patients (defined as those previously diagnosed with COVID-19 and continued to require transmission-based precautions) during the study period.

Main Outcomes and Measures

Weekly counts of new cases of COVID-19, COVID-19-related deaths, and all-cause deaths per 100 residents in the week prior to the initial admission. A stacked difference-in-differences approach was used to compare outcomes for 10 weeks before and 15 weeks after the first admission. Additional analyses examined whether outcomes differed in facilities with staff or personal protective equipment (PPE) shortages.

Results

A matched group of 264 exposed facilities and 518 control facilities was identified. Over the 15-week follow-up period, exposed SNFs had a cumulative increase of 6.94 (95% CI, 2.91-10.98) additional COVID-19 cases per 100 residents compared with control SNFs, a 31.3% increase compared with the sample mean (SD) of 22.2 (26.4). Exposed facilities experienced 2.31 (95% CI, 1.39-3.24) additional cumulative COVID-19-related deaths per 100 residents compared with control facilities, representing a 72.4% increase compared with the sample mean (SD) of 3.19 (5.5). Exposed facilities experiencing potential staff shortage and PPE shortage had larger increases in COVID-19 cases per 100 residents (additional 10.97 [95% CI, 2.76-19.19] cases and additional 14.81 [95% CI, 2.38-27.25] cases, respectively) compared with those without such shortages.

Conclusion

This cohort study suggests that admission of COVID-19-positive patients into SNFs early in the pandemic was associated with preventable COVID-19 cases and mortality among residents, particularly in facilities with potential staff and PPE shortages. The findings speak to the importance of equipping SNFs to adhere to infection-control best practices as they continue to face COVID-19 strains and other respiratory diseases.

Cutaneous manifestations associated with COVID-19 infection at a university hospital in eastern China

BACKGROUND

Coronavirus disease 2019 (COVID-19) affects different organ systems, including the skin. A retrospective analysis of skin manifestations in Chinese outpatient and inpatient settings is lacking. The study aims to analyze cutaneous manifestations in COVID-19 patients and the recurrence or aggravation of previous skin diseases.

MATERIALS AND METHODS

A retrospective cross-sectional study was conducted from November 2022 to July 2023 in a university hospital in eastern China. It involved reverse transcriptase polymerase chain reaction (RT-PCR)-positive COVID-19 patients, documenting various skin manifestations and the recurrence or aggravation of pre-existing skin conditions. The pattern of skin lesions and other variables were assessed.

RESULTS

The study included 303 patients, with 127 males and 176 females. Maculopapular rash was the predominant new cutaneous manifestation (54.92%), mainly in middle-aged individuals. Other findings included urticaria (16.39%), herpes zoster (11.89%), and herpes simplex (4.10%), vesicular rashes (2.46%), purpura (2.05%), erythema multiforme (1.64%), livedo reticularis (0.41%) and so on. Severe disease was associated with herpes zoster and livedo reticularis. Critical COVID-19 cases were linked to vesicular rashes, purpura, and erythema multiforme. The mean time for skin lesion emergence post-infection varied from 3 days for seborrheic dermatitis to 17.48 days for herpes zoster. Vasculitic manifestations correlated with elevated D-dimer levels. A total of 59 cases (19.47%) of recurrent or aggravated skin diseases were reported following infection with COVID-19, with dermatitis being the most common, followed by acne and folliculitis, psoriasis, urticaria, bullous pemphigoid, pemphigus, tinea corporis and androgenetic alopecia.

CONCLUSION

The cutaneous phenotypes delineated in this study expand the dermatologic spectrum associated with COVID-19. Cutaneous manifestations may result from overactive immune responses, complement activation, and microvascular damage. Herpes zoster typically occurs in elderly COVID-19 patients with weaker immune systems or more severe diseases. Purpura and livedo reticularis, although rare, may indicate disease severity. It is possible to predict the course of COVID-19 with different severity through cutaneous manifestations. Recognizing these skin manifestations could aid in predicting COVID-19 severity and guide dermatologists in managing the pandemic response.

No evidence for enhanced disease with human polyclonal SARS-CoV-2 antibody in the ferret model

Since SARS-CoV-2 emerged in late 2019, it spread from China to the rest of the world. An initial concern was the potential for vaccine- or antibody-dependent enhancement (ADE) of disease as had been reported with other coronaviruses. To evaluate this, we first developed a ferret model by exposing ferrets to SARS-CoV-2 by either mucosal inoculation (intranasal/oral/ocular) or inhalation using a small particle aerosol. Mucosal inoculation caused a mild fever and weight loss that resolved quickly; inoculation via either route resulted in virus shedding detected in the nares, throat, and rectum for 7-10 days post-infection. To evaluate the potential for ADE, we then inoculated groups of ferrets intravenously with 0.1, 0.5, or 1 mg/kg doses of a human polyclonal anti-SARS-CoV-2 IgG from hyper-immunized transchromosomic bovines (SAB-185). Twelve hours later, ferrets were challenged by mucosal inoculation with SARS-CoV-2. We found no significant differences in fever, weight loss, or viral shedding after infection between the three antibody groups or the controls. Signs of pathology in the lungs were noted in infected ferrets but no differences were found between control and antibody groups. The results of this study indicate that healthy, young adult ferrets of both sexes are a suitable model of mild COVID-19 and that low doses of specific IgG in SAB-185 are unlikely to enhance the disease caused by SARS-CoV-2.

An Evaluation of the Sensitivity and Specificity of Three COVID-19 Rapid Immunochromatographic Test Kits Compared to Real-Time Reverse Transcriptase-Polymerase Chain Reaction (rRT-PCR) Among Clinical Samples

Background and objective The coronavirus disease 2019 (COVID-19) pandemic has imposed a significant burden on healthcare systems worldwide. This highlights the need for simple, rapid, and affordable diagnostic tests that can serve as alternatives to the existing costly and demanding polymerase chain reaction (PCR) assay, especially in resource-limited countries like Ghana. In light of this, we aimed to assess the diagnostic efficacy of three COVID-19 rapid immunochromatographic antigen test kits vs. real-time reverse transcriptase-PCR (rRT-PCR). Methods This study evaluated the sensitivity and specificity of three COVID-19 rapid immunochromatographic antigen test kits: DG Rapid, SD Rapid, and SS Rapid. They were compared with the gold standard RT-PCR for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antigen in 75 randomly selected archived nasopharyngeal samples. Results Of the 75 samples tested, 38 (50.7%) were positive and 37 (49.3%) were negative for SARS-CoV-2 RNA by rRT-PCR assay. No false positives were recorded. On the other hand, the DG Rapid kit detected 30 (78.9%) true positives and eight (21.1%) false negatives. SD Rapid kit detected 28 (73.7%) true positives and 10 (26.3%) false negatives, while the SS Rapid kit detected 19 (50.0%) true positives and 19 (50.0%) false negatives. While the specificity of each test kit was 100% (95% CI), the sensitivity of the DG Rapid, SD Rapid, and SS Rapid kits was 79%, 74%, and 50% (95% CI), respectively. Higher sensitivities were recorded among samples with cycle threshold (Ct) values <29.99 for each kit. Also, the DG Rapid kit demonstrated 79% excellent agreement with rRT-PCR, while the SD Rapid and SS Rapid kits demonstrated good agreement with rRT-PCR with 73% and 50% Cohen's kappa values, respectively. Conclusions Based on our findings, DG Rapid and SD Rapid kits are reliable alternatives to rRT-PCR for the detection of SARS-CoV-2 infection, especially in resource-limited settings like Ghana.

COVID-19 response in a long-term care facility for people with epilepsy

OBJECTIVE

To assess asymptomatic rates and severity of SARS-CoV-2 infection in people with epilepsy and their healthcare workers in a long-term care facility which had implemented weekly surveillance testing between April 2020 and June 2022.

METHODS

Questionnaires focused on objective and subjective COVID-19 symptoms for people with epilepsy residing in and their healthcare workers at the Chalfont Centre for Epilepsy in June 2022. Demographic information, comorbidities, and seizure frequency were gathered from medical records. We also collected responses on objective and subjective COVID-19 symptoms from healthcare workers who participated in a prospective study assessing the reaction to COVID-19 vaccinations (SAFER).

RESULTS

Fifty-five out of 89 (62%) residents tested positive at least once on weekly PCR testing for SARS-CoV-2 during the period of interest; 20 of those (37%) were asymptomatic. In comparison, of those 63 healthcare workers who tested positive at least once on weekly testing during the same period, only four (6%) were asymptomatic. Of the 159 healthcare workers who also participated in the SAFER study, 41 tested positive at least once, and seven (17%) were completely asymptomatic during infection with SARS-CoV-2.

SIGNIFICANCE

People with epilepsy living in a long-term care facility were more likely to present with asymptomatic SARS-CoV-2 infections than healthcare workers at the same facility. Despite possible bias in the reporting of subjective symptoms due to management-by-proxy, there is no evidence that vulnerable people living in an epilepsy long-term care facility showed reduced resilience towards infections.

PLAIN LANGUAGE SUMMARY

People with epilepsy living in care home facilities had a surprisingly high degree of asymptomatic infections with SARS-CoV-2. Very few residents had severe or fatal outcomes. This is in stark contrast to the widely reported bad outcomes for people without epilepsy in other care homes. People with epilepsy reported significantly less symptoms than their healthcare workers. No changes in seizure frequency during or after infection were observed.

ADLM Guidance Document on Laboratory Diagnosis of Respiratory Viruses

Respiratory viral infections are among the most frequent infections experienced worldwide. The COVID-19 pandemic has highlighted the need for testing and currently several tests are available for the detection of a wide range of viruses. These tests vary widely in terms of the number of viral pathogens included, viral markers targeted, regulatory status, and turnaround time to results, as well as their analytical and clinical performance. Given these many variables, selection and interpretation of testing requires thoughtful consideration. The current guidance document is the authors' expert opinion based on the preponderance of available evidence to address key questions related to best practices for laboratory diagnosis of respiratory viral infections including who to test, when to test, and what tests to use. An algorithm is proposed to help laboratories decide on the most appropriate tests to use for the diagnosis of respiratory viral infections.

A closer look at the link between cycle threshold, clinical features and biomarkers: An observational study in COVID-19 patients

Background

Symptoms for severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) appear 2-3 days after exposure to the virus. Being a virus, detection is primarily by polymerase chain reaction as this offers superior sensitivity and specificity. There was a misconception that patients with low cycle threshold (Ct) have severe coronavirus disease (COVID), and for individuals with higher Ct, it is the other way around. The prognosis for COVID was derived from various biomarkers and physicians heavily relied on them.

Materials and Methods

A cross-sectional study spanning a duration of 2 years was conducted at a tertiary care centre in western India. A total of 201 individuals were included and the correlation between Ct, clinical features and biomarkers was studied.

Results

In the E-gene, 43.28% had lower Ct values and 40.79% had low Ct values in the RdRp gene. 50% of all patients had diabetes, with 60% being between the ages of 61 and 80. 54.1% of hypertension patients belonged to ages between 61 and 80. 90.54% of COVID-positive individuals had lactose dehydrogenase levels ranging from 440 to 760. 79% of patients had a procalcitonin value of more than one but less than six. 79.1% of patients had an erythrocyte sedimentation rate between 36 and 90.

Conclusion

Ct value though has a research value; it is a poor prognostic marker when compared to the various biomarkers that have been studied earlier. We cannot conclusively state that all our findings are accurate due to a lack of data but further research into the prognostic value of Ct should be conducted which will help in the ongoing scenario.

COVID-19 outbreak and genomic investigation in an inpatient behavioral health unit

Background

Inpatient behavioral health units (BHUs) had unique challenges in implementing interventions to mitigate coronavirus disease 2019 (COVID-19) transmission, in part due to socialization in BHU settings. The objective of this study was to identify the transmission routes and the efficacy of the mitigation strategies employed during a COVID-19 outbreak in an inpatient BHU during the Omicron surge from December 2021 to January 2022.

Methods

An outbreak investigation was performed after identifying 2 COVID-19-positive BHU inpatients on December 16 and 20, 2021. Mitigation measures involved weekly point prevalence testing for all inpatients, healthcare workers (HCWs), and staff, followed by infection prevention mitigation measures and molecular surveillance. Whole-genome sequencing on a subset of COVID-19-positive individuals was performed to identify the outbreak source. Finally, an outbreak control sustainability plan was formulated for future BHU outbreak resurgences.

Results

We identified 35 HCWs and 8 inpatients who tested positive in the BHU between December 16, 2021, and January 17, 2022. We generated severe acute respiratory coronavirus virus 2 (SARS-CoV-2) genomes from 15 HCWs and all inpatients. Phylogenetic analyses revealed 3 distinct but genetically related clusters: (1) an HCW and inpatient outbreak likely initiated by staff, (2) an HCW and inpatient outbreak likely initiated by an inpatient visitor, and (3) an HCW-only cluster initiated by staff.

Conclusions

Distinct transmission clusters are consistent with multiple, independent SARS-CoV-2 introductions with further inpatient transmission occurring in communal settings. The implemented outbreak control plan comprised of enhanced personal protective equipment requirements, limited socialization, and molecular surveillance likely minimized disruptions to patient care as a model for future pandemics.

Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 Among Residents and Employees in a Veterans Affairs Community Living Center: A 42-Month Prospective Cohort Study

Background

Understanding routes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in long-term care facilities is essential for the development of effective control measures.

Methods

Between March 1, 2020, and August 31, 2023, we identified coronavirus disease 2019 (COVID-19) cases among residents and employees in a Veterans Affairs community living center that conducted routine screening for asymptomatic COVID-19. Contact tracing was conducted to identify suspected transmission events, and whole genome sequencing was performed to determine the relatedness of SARS-CoV-2 samples.

Results

During the 42-month study period, 269 cases of COVID-19 were diagnosed, including 199 employees and 70 residents. A total of 48 (24.1%) employees and 30 (42.9%) residents were asymptomatic. Sequencing analysis provided support for multiple events in which employees transmitted SARS-CoV-2 to co-workers and residents. There was 1 episode of likely transmission of SARS-CoV-2 from one resident to another resident, but no documented transmissions from residents to employees.

Conclusions

Transmission of SARS-CoV-2 in the community living center predominantly involved transmission from employees to co-workers and residents. There is a need for improved measures to prevent transmission of SARS-CoV-2 by healthcare personnel.

Commensal bacteria inhibit viral infections via a tryptophan metabolite

There is growing appreciation that commensal bacteria impact the outcome of viral infections, though the specific bacteria and their underlying mechanisms remain poorly understood. Studying a simian-human immunodeficiency virus (SHIV)-challenged cohort of pediatric nonhuman primates, we bioinformatically associated Lactobacillus gasseri and the bacterial family Lachnospiraceae with enhanced resistance to infection. We experimentally validated these findings by demonstrating two different Lachnospiraceae isolates, Clostridium immunis and Ruminococcus gnavus, inhibited HIV replication in vitro and ex vivo. Given the link between tryptophan catabolism and HIV disease severity, we found that an isogenic mutant of C. immunis that lacks the aromatic amino acid aminotransferase (ArAT) gene, which is key to metabolizing tryptophan into 3-indolelactic acid (ILA), no longer inhibits HIV infection. Intriguingly, we confirmed that a second commensal bacterium also inhibited HIV in an ArAT-dependent manner, thus establishing the generalizability of this finding. In addition, we found that purified ILA inhibited HIV infection by agonizing the aryl hydrocarbon receptor (AhR). Given that the AhR has been implicated in the control of multiple viral infections, we demonstrated that C. immunis also inhibited human cytomegalovirus (HCMV) infection in an ArAT-dependent manner. Importantly, metagenomic analysis of individuals at-risk for HIV revealed that those who ultimately acquired HIV had a lower fecal abundance of the bacterial ArAT gene compared to individuals who did not, which indicates our findings translate to humans. Taken together, our results provide mechanistic insights into how commensal bacteria decrease susceptibility to viral infections. Moreover, we have defined a microbiota-driven antiviral pathway that offers the potential for novel therapeutic strategies targeting a broad spectrum of viral pathogens.

Magnitude and determinants of excess total, age-specific and sex-specific all-cause mortality in 24 countries worldwide during 2020 and 2021: results on the impact of the COVID-19 pandemic from the C-MOR project

INTRODUCTION

To examine the impact of the COVID-19 pandemic on mortality, we estimated excess all-cause mortality in 24 countries for 2020 and 2021, overall and stratified by sex and age.

METHODS

Total, age-specific and sex-specific weekly all-cause mortality was collected for 2015-2021 and excess mortality for 2020 and 2021 was calculated by comparing weekly 2020 and 2021 age-standardised mortality rates against expected mortality, estimated based on historical data (2015-2019), accounting for seasonality, and long-term and short-term trends. Age-specific weekly excess mortality was similarly calculated using crude mortality rates. The association of country and pandemic-related variables with excess mortality was investigated using simple and multilevel regression models.

RESULTS

Excess cumulative mortality for both 2020 and 2021 was found in Austria, Brazil, Belgium, Cyprus, England and Wales, Estonia, France, Georgia, Greece, Israel, Italy, Kazakhstan, Mauritius, Northern Ireland, Norway, Peru, Poland, Slovenia, Spain, Sweden, Ukraine, and the USA. Australia and Denmark experienced excess mortality only in 2021. Mauritius demonstrated a statistically significant decrease in all-cause mortality during both years. Weekly incidence of COVID-19 was significantly positively associated with excess mortality for both years, but the positive association was attenuated in 2021 as percentage of the population fully vaccinated increased. Stringency index of control measures was positively and negatively associated with excess mortality in 2020 and 2021, respectively.

CONCLUSION

This study provides evidence of substantial excess mortality in most countries investigated during the first 2 years of the pandemic and suggests that COVID-19 incidence, stringency of control measures and vaccination rates interacted in determining the magnitude of excess mortality.

A joint Bayesian hierarchical model for estimating SARS-CoV-2 genomic and subgenomic RNA viral dynamics and seroconversion

Understanding the viral dynamics of and natural immunity to the severe acute respiratory syndrome coronavirus 2 is crucial for devising better therapeutic and prevention strategies for coronavirus disease 2019 (COVID-19). Here, we present a Bayesian hierarchical model that jointly estimates the genomic RNA viral load, the subgenomic RNA (sgRNA) viral load (correlated to active viral replication), and the rate and timing of seroconversion (correlated to presence of antibodies). Our proposed method accounts for the dynamical relationship and correlation structure between the two types of viral load, allows for borrowing of information between viral load and antibody data, and identifies potential correlates of viral load characteristics and propensity for seroconversion. We demonstrate the features of the joint model through application to the COVID-19 post-exposure prophylaxis study and conduct a cross-validation exercise to illustrate the model's ability to impute the sgRNA viral trajectories for people who only had genomic RNA viral load data.

Single-center Outcomes After Liver Transplantation With SARS-CoV-2-Positive Donors: An Argument for Increased Utilization

Background

The COVID-19 pandemic has led to an increase in SARS-CoV-2-test positive potential organ donors. The benefits of life-saving liver transplantation (LT) must be balanced against the potential risk of donor-derived viral transmission. Although emerging evidence suggests that the use of COVID-19-positive donor organs may be safe, granular series thoroughly evaluating safety are still needed. Results of 29 consecutive LTs from COVID-19-positive donors at a single center are presented here.

Methods

A retrospective cohort study of LT recipients between April 2020 and December 2022 was conducted. Differences between recipients of COVID-19-positive (n = 29 total; 25 index, 4 redo) and COVID-19-negative (n = 472 total; 454 index, 18 redo) deceased donor liver grafts were compared.

Results

COVID-19-positive donors were significantly younger (P = 0.04) and had lower kidney donor profile indices (P = 0.04) than COVID-19-negative donors. Recipients of COVID-19-positive donor grafts were older (P = 0.04) but otherwise similar to recipients of negative donors. Donor SARS-CoV-2 infection status was not associated with a overall survival of recipients (hazard ratio, 1.11; 95% confidence interval, 0.24-5.04; P = 0.89). There were 3 deaths among recipients of liver grafts from COVID-19-positive donors. No death seemed virally mediated because there was no qualitative association with peri-LT antispike antibody titers, post-LT prophylaxis, or SARS-CoV-2 variants.

Conclusions

The utilization of liver grafts from COVID-19-positive donors was not associated with a decreased overall survival of recipients. There was no suggestion of viral transmission from donor to recipient. The results from this large single-center study suggest that COVID-19-positive donors may be used safely to expand the deceased donor pool.

Progranulin promotes regulatory T cells plasticity by mitochondrial metabolism through AMPK/PGC-1α pathway in ARDS

As the aging population increases, the focus on elderly patients with acute respiratory distress syndrome (ARDS) is also increasing. In this article, we found progranulin (PGRN) differential expression in ARDS patients and healthy controls, even in young and old ARDS patients. Its expression strongly correlates with several cytokines in both young and elderly ARDS patients. PGRN has comparable therapeutic effects in young and elderly mice with lipopolysaccharide-induced acute lung injury, manifesting as lung injury, apoptosis, inflammation, and regulatory T cells (Tregs) differentiation. Considering that Tregs differentiation relies on metabolic reprogramming, we discovered that Tregs differentiation was mediated by mitochondrial function, especially in the aged population. Furthermore, we demonstrated that PGRN alleviated the mitochondrial damage during Tregs differentiation through the AMPK/PGC-1α pathway in T cells. Collectively, PGRN may regulate mitochondria function to promote Tregs differentiation through the AMPK/PGC-1α pathway to improve ARDS.

Molecular Epidemiology of SARS-CoV-2 within Accra Metropolis Postlockdown

Introduction

Currently, sequencing has been the only tool for the identification of circulating severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants. However, it is known to be an expensive and laborious approach involving high technical expertise. Considering the reduced adherence to preventive measures postlockdown in Accra, this study presents an alternative method that leverages polymerase chain reaction (PCR) to identify circulating SARS-CoV-2 variants in the Accra Metropolis postlockdown.

Methods

This prospective cross-sectional study was conducted between July and December 2022. Nasopharyngeal samples were collected from 268 consenting participants. Samples were subjected to nucleic acid extraction and followed by real-time polymerase chain reaction for the detection and quantification of SARS-CoV-2 RNA. SARS-CoV-2 positive samples were subsequently subjected to variant identification using rapid PCR. Findings. The prevalence of SARS-CoV-2 within the Accra Metropolis was 30.2%. The majority of the SARS-CoV-2 infection was diagnosed in females, participants aged 41-50 years, and symptomatic participants. Participants aged ≤10 years and females recorded the highest viral load while participants aged 41-50 years recorded the highest number of infections. The SARS-CoV-2 variants detected were Alpha (64.2%), Delta (22.2%), and Omicron (13.6%). Predictors of SARS-CoV-2 infection identified were chills, cough, headache, body weakness, sore throat, and dyspnoea in order of decreasing association with SARS-CoV-2 infection. There was a strong association between symptom status, gender, age, and SARS-CoV-2 infection.

Conclusion

There was a high prevalence of SARS-CoV-2 within the Accra Metropolis postlockdown within the sampling period. The Alpha variant of SARS-CoV-2 is the predominant circulating variant, and persons presenting with symptoms are most likely to be diagnosed with COVID-19. Children aged ≤10 years serve as a reservoir for infection transmission.

Timing and Predictors of Loss of Infectivity Among Healthcare Workers With Mild Primary and Recurrent COVID-19: A Prospective Observational Cohort Study

BACKGROUND

There is a need to understand the duration of infectivity of primary and recurrent coronavirus disease 2019 (COVID-19) and identify predictors of loss of infectivity.

METHODS

Prospective observational cohort study with serial viral culture, rapid antigen detection test (RADT) and reverse transcription polymerase chain reaction (RT-PCR) on nasopharyngeal specimens of healthcare workers with COVID-19. The primary outcome was viral culture positivity as indicative of infectivity. Predictors of loss of infectivity were determined using multivariate regression model. The performance of the US Centers for Disease Control and Prevention (CDC) criteria (fever resolution, symptom improvement, and negative RADT) to predict loss of infectivity was also investigated.

RESULTS

In total, 121 participants (91 female [79.3%]; average age, 40 years) were enrolled. Most (n = 107, 88.4%) had received ≥3 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine doses, and 20 (16.5%) had COVID-19 previously. Viral culture positivity decreased from 71.9% (87/121) on day 5 of infection to 18.2% (22/121) on day 10. Participants with recurrent COVID-19 had a lower likelihood of infectivity than those with primary COVID-19 at each follow-up (day 5 odds ratio [OR], 0.14; P < .001]; day 7 OR, 0.04; P = .003]) and were all non-infective by day 10 (P = .02). Independent predictors of infectivity included prior COVID-19 (adjusted OR [aOR] on day 5, 0.005; P = .003), an RT-PCR cycle threshold [Ct] value <23 (aOR on day 5, 22.75; P < .001) but not symptom improvement or RADT result.The CDC criteria would identify 36% (24/67) of all non-infectious individuals on day 7. However, 17% (5/29) of those meeting all the criteria had a positive viral culture.

CONCLUSIONS

Infectivity of recurrent COVID-19 is shorter than primary infections. Loss of infectivity algorithms could be optimized.

Early predictors of intensive care unit admission among COVID-19 patients in Qatar

Background

COVID-19 is associated with significant morbidity and mortality. This study aimed to explore the early predictors of intensive care unit (ICU) admission among patients with COVID-19.

Methods

This was a case-control study of adult patients with confirmed COVID-19. Cases were defined as patients admitted to ICU during the period February 29-May 29, 2020. For each case enrolled, one control was matched by age and gender.

Results

A total of 1,560 patients with confirmed COVID-19 were included. Each group included 780 patients with a predominant male gender (89.7%) and a median age of 49 years (interquartile range = 18). Predictors independently associated with ICU admission were cardiovascular disease (adjusted odds ratio (aOR) = 1.64, 95% confidence interval (CI): 1.16-2.32, p = 0.005), diabetes (aOR = 1.52, 95% CI: 1.08-2.13, p = 0.016), obesity (aOR = 1.46, 95% CI: 1.03-2.08, p = 0.034), lymphopenia (aOR = 2.69, 95% CI: 1.80-4.02, p < 0.001), high AST (aOR = 2.59, 95% CI: 1.53-4.36, p < 0.001), high ferritin (aOR = 1.96, 95% CI: 1.40-2.74, p < 0.001), high CRP (aOR = 4.09, 95% CI: 2.81-5.96, p < 0.001), and dyspnea (aOR = 2.50, 95% CI: 1.77-3.54, p < 0.001).

Conclusion

Having cardiovascular disease, diabetes, obesity, lymphopenia, dyspnea, and increased AST, ferritin, and CRP were independent predictors for ICU admission in patients with COVID-19.

Control of SARS-CoV-2 infection in skilled nursing facilities in Detroit, Michigan: a model for emerging infectious diseases

An infection prevention bundle that consisted of the development of a response team, public-academic partnership, daily assessment, regular testing, isolation, and environmental controls was implemented in 26 skilled nursing facilities in Detroit, Michigan (March 2020-April 2021). This intervention was associated with sustained control of severe acute respiratory coronavirus virus 2 infection among residents and staff.

Latent and incubation periods of Delta, BA.1, and BA.2 variant cases and associated factors: a cross-sectional study in China

BACKGROUND

The latent and incubation periods characterize the transmission of infectious viruses and are the basis for the development of outbreak prevention and control strategies. However, systematic studies on the latent period and associated factors with the incubation period for SAS-CoV-2 variants are still lacking. We inferred the two durations of Delta, BA.1, and BA.2 cases and analyzed the associated factors.

METHODS

The Delta, BA.1, and BA.2 (and its lineages BA.2.2 and BA.2.76) cases with clear transmission chains and infectors from 10 local SAS-CoV-2 epidemics in China were enrolled. The latent and incubation periods were fitted by the Gamma distribution, and associated factors were analyzed using the accelerated failure time model.

RESULTS

The mean latent period for 672 Delta, 208 BA.1, and 677 BA.2 cases was 4.40 (95%CI: 4.24 ~ 4.63), 2.50 (95%CI: 2.27 ~ 2.76), and 2.58 (95%CI: 2.48 ~ 2.69) days, respectively, with 85.65% (95%CI: 83.40 ~ 87.77%), 97.80% (95%CI: 96.35 ~ 98.89%), and 98.87% (95%CI: 98.40 ~ 99.27%) of them starting to shed viruses within 7 days after exposure. In 405 Delta, 75 BA.1, and 345 BA.2 symptomatic cases, the mean latent period was 0.76, 1.07, and 0.79 days shorter than the mean incubation period [5.04 (95%CI: 4.83 ~ 5.33), 3.42 (95%CI: 3.00 ~ 3.89), and 3.39 (95%CI: 3.24 ~ 3.55) days], respectively. No significant difference was observed in the two durations between BA.1 and BA.2 cases. After controlling for the sex, clinical severity, vaccination history, number of infectors, the length of exposure window and shedding window, the latent period [Delta: exp(β) = 0.81, 95%CI: 0.66 ~ 0.98, p = 0.034; Omicron: exp(β) = 0.82, 95%CI: 0.71 ~ 0.94, p = 0.004] and incubation period [Delta: exp(β) = 0.69, 95%CI: 0.55 ~ 0.86, p < 0.001; Omicron: exp(β) = 0.83, 95%CI: 0.72 ~ 0.96, p = 0.013] were significantly shorter in 18 ~ 49 years but did not change significantly in ≥ 50 years compared with 0 ~ 17 years.

CONCLUSION

Pre-symptomatic transmission can occur in Delta, BA.1, and BA.2 cases. The latent and incubation periods between BA.1 and BA.2 were similar but shorter compared with Delta. Age may be associated with the latent and incubation periods of SARS-CoV-2.

Bio-based ionic liquid filter with enhanced electrostatic attraction for outside filtration and inside collection of viral aerosols

Hazardous biological pathogens in the air pose a significant public environmental health concern as infected individuals emit virus-laden aerosols (VLAs) during routine respiratory activities. Mask-wearing is a key preventive measure, but conventional filtration methods face challenges, particularly in high humidity conditions, where electrostatic charge decline increases the risk of infection. This study introduces a bio-based air filter comprising glycine ionic liquids (GILs) and malleable polymer composite (GILP) with high polarity and functional group density, which are wrapped around a melamine-formaldehyde (MF) resin skeleton, forming a conductive, porous GIL functionized ionic network air filter (GILP@MF). When subjected to low voltage, the GILP@MF composite efficiently captures VLAs including nanoscale virus particles through the enhanced electrostatic attraction, especially in facing high humidity bioaerosols exhaled by human body. The filtration/collection efficiency and quality factor can reach 98.3% and 0.264 Pa-1 at 0.1 m s-1, respectively. This innovative filter provides effective VLA protection and offers potential for non-invasive respiratory virus sampling, advancing medical diagnosis efforts.

Wastewater Surveillance for Identifying SARS-CoV-2 Infections in Long-Term Care Facilities, Kentucky, USA, 2021-2022

Persons living in long-term care facilities (LTCFs) were disproportionately affected by COVID-19. We used wastewater surveillance to detect SARS-CoV-2 infection in this setting by collecting and testing 24-hour composite wastewater samples 2-4 times weekly at 6 LTCFs in Kentucky, USA, during March 2021-February 2022. The LTCFs routinely tested staff and symptomatic and exposed residents for SARS-CoV-2 using rapid antigen tests. Of 780 wastewater samples analyzed, 22% (n = 173) had detectable SARS-CoV-2 RNA. The LTCFs reported 161 positive (of 16,905) SARS-CoV-2 clinical tests. The wastewater SARS-CoV-2 signal showed variable correlation with clinical test data; we observed the strongest correlations in the LTCFs with the most positive clinical tests (n = 45 and n = 58). Wastewater surveillance was 48% sensitive and 80% specific in identifying SARS-CoV-2 infections found on clinical testing, which was limited by frequency, coverage, and rapid antigen test performance.

Belief, knowledge, attitude and practices towards COVID-19 amongst residents of Abuja, Nigeria: implications for pandemic preparedness

Introduction

coronavirus disease, (COVID-19), was a pandemic with high global morbidity and mortality, partly due to a lack of preparedness. People´s knowledge, belief, attitude, and perception of disease outbreaks may affect their response, and this may impact their health-related behavior. This study was designed to determine the pattern of belief, knowledge, attitude, and practices (BKAP) of residents of Abuja, Nigeria, towards the COVID-19 pandemic. The outcome of the study may help to make informed decisions on future pandemic preparedness.

Methods

a cross-sectional study with data collected online about the local perceptions and common concerns, beliefs, misconceptions, attitudes, and conspiracy theories amongst residents of the FCT. A self-reported validated e-questionnaire prepared on Google Forms was used. The obtained data was downloaded on Excel sheet and then exported to SPSS for analysis.

Results

there were one thousand eight hundred and seventy-three (1,873) respondents, 1017 (54.3%) females and 856 (45.7%) males. Participants were majorly knowledgeable, the majority (31.2%) were in the 41-50 years age group. Surprisingly, about 17% did not know that wearing a face mask could prevent COVID-19. About 25% still met in crowded places, and slightly more than 33% did not wear outdoor masks. The highest knowledge of COVID-19 was found among people in the age range 41-50 years, females, University graduates, married people, and healthcare personnel, particularly doctors.

Conclusion

our study concludes that the overall population of Abuja had good knowledge and, a positive attitude, with pockets of poor attitudes and bad practices born out of misconceptions and infodemics.

A retrospective cohort study on early antibiotic use in vaccinated and unvaccinated COVID-19 patients

The bacteriophage behavior of SARS-CoV-2 during the acute and post-COVID-19 phases appears to be an important factor in the development of the disease. The early use of antibiotics seems to be crucial to inhibit disease progression-to prevent viral replication in the gut microbiome, and control toxicological production from the human microbiome. To study the impact of specific antibiotics on recovery from COVID-19 and long COVID (LC) taking into account: vaccination status, comorbidities, SARS-CoV-2 wave, time of initiation of antibiotic therapy and concomitant use of corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs). A total of 211 COVID-19 patients were included in the study: of which 59 were vaccinated with mRNA vaccines against SARS-CoV-2 while 152 were unvaccinated. Patients were enrolled in three waves: from September 2020 to October 2022, corresponding to the emergence of the pre-Delta, Delta, and Omicron variants of the SARS-CoV-2 virus. The three criteria for enrolling patients were: oropharyngeal swab positivity or fecal findings; moderate symptoms with antibiotic intake; and measurement of blood oxygen saturation during the period of illness. The use of antibiotic combinations, such as amoxicillin with clavulanic acid (875 + 125 mg tablets, every 12 h) plus rifaximin (400 mg tablets every 12 h), as first choice, as suggested from the previous data, or azithromycin (500 mg tablets every 24 h), plus rifaximin as above, allows healthcare professionals to focus on the gut microbiome and its implications in COVID-19 disease during patient care. The primary outcome measured in this study was the estimated average treatment effect, which quantified the difference in mean recovery between patients receiving antibiotics and those not receiving antibiotics at 3 and 9 days after the start of treatment. In the analysis, both vaccinated and unvaccinated groups had a median illness duration of 7 days (interquartile range [IQR] 6-9 days for each; recovery crude hazard ratio [HR] = 0.94, p = 0.700). The median illness duration for the pre-Delta and Delta waves was 8 days (IQR 7-10 days), while it was shorter, 6.5 days, for Omicron (IQR 6-8 days; recovery crude HR = 1.71, p < 0.001). These results were confirmed by multivariate analysis. Patients with comorbidities had a significantly longer disease duration: median 8 days (IQR 7-10 days) compared to 7 days (IQR 6-8 days) for those without comorbidities (crude HR = 0.75, p = 0.038), but this result was not confirmed in multivariate analysis as statistical significance was lost. Early initiation of antibiotic therapy resulted in a significantly shorter recovery time (crude HR = 4.74, p < 0.001). Concomitant use of NSAIDs did not reduce disease duration and in multivariate analysis prolonged the disease (p = 0.041). A subgroup of 42 patients receiving corticosteroids for a median of 3 days (IQR 3-6 days) had a longer recovery time (median 9 days, IQR 8-10 days) compared to others (median 7 days, IQR 6-8 days; crude HR = 0.542, p < 0.001), as confirmed also by the adjusted HR. In this study, a statistically significant reduction in recovery time was observed among patients who received early antibiotic treatment. Early initiation of antibiotics played a crucial role in maintaining higher levels of blood oxygen saturation. In addition, it is worth noting that a significant number of patients who received antibiotics in the first 3 days and for a duration of 7 days, during the acute phase did not develop LC.

Environmental surface monitoring as a noninvasive method for SARS-CoV-2 surveillance in community settings: Lessons from a university campus study

Environmental testing of high-touch objects is a potential noninvasive approach for monitoring population-level trends of SARS-CoV-2 and other respiratory viruses within a defined setting. We aimed to determine the association between SARS-CoV-2 contamination on high-touch environmental surfaces, community level case incidence, and university student health data. Environmental swabs were collected from January 2022 to November 2022 from high-touch objects and surfaces from five locations on a large university campus in Florida, USA. RT-qPCR was used to detect and quantify viral RNA, and a subset of positive samples was analyzed by viral genome sequencing to identify circulating lineages. During the study period, we detected SARS-CoV-2 viral RNA on 90.7 % of 162 tested samples. Levels of environmental viral RNA correlated with trends in community-level activity and case reports from the student health center. A significant positive correlation was observed between the estimated viral gene copy number in environmental samples and the weekly confirmed cases at the university. Viral sequencing data from environmental samples identified lineages concurrently circulating in the local community and state based on genomic surveillance data. Further, we detected emerging variants in environmental samples prior to their identification by clinical genomic surveillance. Our results demonstrate the utility of viral monitoring on high-touch environmental surfaces for SARS-CoV-2 surveillance at a community level. In communities with delayed or limited testing facilities, immediate environmental surface testing may considerably inform epidemic dynamics.

Excess Mortality During 2020 in Spain: The Most Affected Population, Age, and Educational Group by the COVID-19 Pandemic

OBJECTIVE

The objective of this work was to study mortality increase in Spain during the first and second academic semesters of 2020, coinciding with the first 2 waves of the Covid-19 pandemic; by sex, age, and education.

METHODS

An observational study was carried out, using linked populations and deaths' data from 2017 to 2020. The mortality rates from all causes and leading causes other than Covid-19 during each semester of 2020, compared to the 2017-2019 averages for the same semester, was also estimated. Mortality rate ratios (MRR) and differences were used for comparison.

RESULTS

All-cause mortality rates increased in 2020 compared to pre-covid, except among working-age, (25-64 years) highly-educated women. Such increases were larger in lower-educated people between the working age range, in both 2020 semesters, but not at other ages. In the elderly, the MMR in the first semester in women and men were respectively, 1.14, and 1.25 among lower-educated people, and 1.28 and 1.23 among highly-educated people. In the second semester, the MMR were 1.12 in both sexes among lower-educated people and 1.13 in women and 1.16 in men among highly-educated people.

CONCLUSION

Lower-educated people within working age and highly-educated people at older ages showed the greatest increase in all-cause mortality in 2020, compared to the pre-pandemic period.

Elevated levels of cell-free NKG2D-ligands modulate NKG2D surface expression and compromise NK cell function in severe COVID-19 disease

Introduction

It is now clear that coronavirus disease 19 (COVID-19) severity is associated with a dysregulated immune response, but the relative contributions of different immune cells is still not fully understood. SARS CoV-2 infection triggers marked changes in NK cell populations, but there are contradictory reports as to whether these effector lymphocytes play a protective or pathogenic role in immunity to SARS-CoV-2.

Methods

To address this question we have analysed differences in the phenotype and function of NK cells in SARS-CoV-2 infected individuals who developed either very mild, or life-threatening COVID-19 disease.

Results

Although NK cells from patients with severe disease appeared more activated and the frequency of adaptive NK cells was increased, they were less potent mediators of ADCC than NK cells from patients with mild disease. Further analysis of peripheral blood NK cells in these patients revealed that a population of NK cells that had lost expression of the activating receptor NKG2D were a feature of patients with severe disease and this correlated with elevated levels of cell free NKG2D ligands, especially ULBP2 and ULBP3 in the plasma of critically ill patients. In vitro, culture in NKG2DL containing patient sera reduced the ADCC function of healthy donor NK cells and this could be blocked by NKG2DL-specific antibodies.

Discussion

These observations of reduced NK function in severe disease are consistent with the hypothesis that defects in immune surveillance by NK cells permit higher levels of viral replication, rather than that aberrant NK cell function contributes to immune system dysregulation and immunopathogenicity.

An intranasal live-attenuated SARS-CoV-2 vaccine limits virus transmission

The development of effective SARS-CoV-2 vaccines has been essential to control COVID-19, but significant challenges remain. One problem is intramuscular administration, which does not induce robust mucosal immune responses in the upper airways-the primary site of infection and virus shedding. Here we compare the efficacy of a mucosal, replication-competent yet fully attenuated virus vaccine, sCPD9-ΔFCS, and the monovalent mRNA vaccine BNT162b2 in preventing transmission of SARS-CoV-2 variants B.1 and Omicron BA.5 in two scenarios. Firstly, we assessed the protective efficacy of the vaccines by exposing vaccinated male Syrian hamsters to infected counterparts. Secondly, we evaluated transmission of the challenge virus from vaccinated and subsequently challenged male hamsters to naïve contacts. Our findings demonstrate that the live-attenuated vaccine (LAV) sCPD9-ΔFCS significantly outperformed the mRNA vaccine in preventing virus transmission in both scenarios. Our results provide evidence for the advantages of locally administered LAVs over intramuscularly administered mRNA vaccines in preventing infection and reducing virus transmission.

Silent battles: immune responses in asymptomatic SARS-CoV-2 infection

SARS-CoV-2 infections manifest with a broad spectrum of presentations, ranging from asymptomatic infections to severe pneumonia and fatal outcomes. This review centers on asymptomatic infections, a widely reported phenomenon that has substantially contributed to the rapid spread of the pandemic. In such asymptomatic infections, we focus on the role of innate, humoral, and cellular immunity. Notably, asymptomatic infections are characterized by an early and robust innate immune response, particularly a swift type 1 IFN reaction, alongside a rapid and broad induction of SARS-CoV-2-specific T cells. Often, antibody levels tend to be lower or undetectable after asymptomatic infections, suggesting that the rapid control of viral replication by innate and cellular responses might impede the full triggering of humoral immunity. Even if antibody levels are present in the early convalescent phase, they wane rapidly below serological detection limits, particularly following asymptomatic infection. Consequently, prevalence studies reliant solely on serological assays likely underestimate the extent of community exposure to the virus.

Transfer Trauma Among Nursing Home Residents: Development of a Composite Measure

BACKGROUND AND OBJECTIVES

Nursing home (NH)-to-NH transfers place NH residents at risk for developing transfer trauma. We aimed to develop a composite measure of transfer trauma and apply it among those transferring before and during the pandemic.

RESEARCH DESIGN AND METHODS

Cross-sectional cohort analysis of long-stay NH residents with a NH-to-NH transfer. Minimum Data Set data (2018-2020) were used to create the cohorts. A composite measure of transfer trauma was developed (2018 cohort) and applied to the 2019 and 2020 cohorts. We analyzed resident characteristics and conducted logistic regression analyses to compare rates of transfer trauma between periods.

RESULTS

In 2018, 794 residents were transferred; 242 (30.5%) met the criteria for transfer trauma. In the 2019 and 2020, 750 residents (2019) and 795 (2020) were transferred. In 2019 cohort, 30.7% met the criteria for transfer trauma, and 21.9% in 2020 cohort. During the pandemic, a higher proportion of transferred residents left the facility before the first quarterly assessment. Among residents who stayed in NH for their quarterly assessment, after adjusting for demographic characteristics, residents in the 2020 cohort were less likely to experience transfer trauma than those in the 2019 cohort (adjusted odds ratio [AOR] = 0.64, 95% confidence interval [CI]: 0.51, 0.81). However, residents in 2020 cohort were two times more likely to die (AOR = 1.94, 95% CI: 1.15, 3.26) and 3 times more likely to discharge within 90 days after transfer (AOR = 2.86, 95% CI: 2.30, 3.56) compared with those in 2019 cohort.

DISCUSSION AND IMPLICATIONS

These findings highlight how common transfer trauma is after NH-to-NH transfer and the need for further research to mitigate negative outcomes associated with the transfer in this vulnerable population.

Markers of community outbreak and facility type for mitigation of COVID-19 in long-term care homes in Ontario, Canada: Insights and implications from a time-series analysis

PURPOSE

The resident deaths among Long Term Care Home (LTCH) accounted for more than 65% of total deaths in the province of Ontario, Canada, during March 29 to June 3, 2020, yet not all LTCHs were severely affected.

METHODS

We carried out a retrospective cohort study, with case control for questions for which data allowed, with LTCH COVID-19 databases obtained from Ontario's Ministry of Long Term Care. We performed a combined temporal and spatial data analysis of COVID-19 cases and deaths among LTCH residents, identified trends, contributing factors, and early markers of LTCH outbreak severity.

RESULTS

Our analysis shows that for-profit LTCHs had higher death-to-bed ratio, also with an average rate of increase of death-to-bed ratio higher for for-profit homes than other types of management. We find from uni- and multi-variable analyses (linear and nonlinear) that staff infection has the strongest association with death-to-bed ratio from among the descriptor variables considered, reflecting the risk of the disease in the health region/community. We also identify a delay of up to 8 days between the trends in fatalities among individuals outside LTCHs and that of LTCH residents. We did find an association between policy change to single LTCH/staff and reduction in weekly LTCH resident death, albeit with an expected time delay of about 7-10 days.

CONCLUSIONS

The association between the risk of COVID-19 in the health region and the deaths among LTCH residents, and the delay between fatality among individuals residing outside and inside LTCHs suggests that fatality in a health region could be a predictor of outbreak in LTCHs within the same health region.

Cycle threshold of SARS-CoV-2 RT-PCR as a driver of retesting

SARS-CoV-2 RT-PCR is a critical and, at times, limited resource. Frequent Retesting of patients may strain testing infrastructure unduly. Recommendations that include cycle threshold (Ct) cutoffs may incentivize early retesting when the Ct value is reported. We aimed to investigate patterns of retesting in association with initial Ct-values. We performed a retrospective analysis of RT-PCR results (including Ct-values) for patients from whom ≥ 2 samples were collected within 14 days, the first of which had to be positive. We calculated absolute and baseline-corrected kinetics of Ct-values over time, as well as the median initial Ct-values in dependence of the timing of the first retesting and the time until RT-PCR negativity for SARS-CoV-2. Retesting after an initial positive SARS-CoV-2 RT-PCR was most commonly performed on day 7, with patients being retested as early as day 1. The majority of patients retested within 14 days remained SARS-CoV-2 positive in the RT-PCR. Baseline-corrected Ct-values showed a quasi-linear increase over 14 days since the initial positive result. Both the timing until the first retesting and until RT-PCR negativity were inversely correlated with the initial Ct-value. The timing of retesting after a positive SARS-CoV-2 RT-PCR appears to be significantly influenced by the initial Ct-value. Although it can be assumed that Ct-values will increase steadily over time, strategies that rely on rigid Ct-cutoffs should be discussed critically, not only because of methodological caveats but also because of the strain on testing infrastructure caused by the incentive for early retesting that Ct-values apparently represent.

Cost-Effectiveness of Universal Asymptomatic Preoperative SARS-CoV-2 Polymerase Chain Reaction Screening: A Cost-Utility Analysis

BACKGROUND

An early report has shown the clinical benefit of the asymptomatic preoperative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) screening test, and some clinical guidelines recommended this test. However, the cost-effectiveness of asymptomatic screening was not evaluated. We aimed to investigate the cost-effectiveness of universal preoperative screening of asymptomatic patients for SARS-CoV-2 using polymerase chain reaction (PCR) testing.

METHODS

We evaluated the cost-effectiveness of asymptomatic screening using a decision tree model from a payer perspective, assuming that the test-positive rate was 0.07% and the screening cost was 8500 Japanese yen (JPY) (approximately 7601 US dollars [USD]). The input parameter was derived from the available evidence reported in the literature. A willingness-to-pay threshold was set at 5 000 000 JPY/quality-adjusted life-year (QALY).

RESULTS

The incremental cost of 1 death averted was 74 469 236 JPY (approximately 566 048 USD) and 291 123 368 JPY/QALY (approximately 2 212 856 USD/QALY), which was above the 5 000 000 JPY/QALY willingness-to-pay threshold. The incremental cost-effectiveness ratio fell below 5 000 000 JPY/QALY only when the test-positive rate exceeded 0.739%. However, when the probability of developing a postoperative pulmonary complication among SARS-CoV-2-positive patients was below 0.22, asymptomatic screening was never cost-effective, regardless of how high the test-positive rate became.

CONCLUSIONS

Asymptomatic preoperative universal SARS-CoV-2 PCR screening is not cost-effective in the base case analysis. The cost-effectiveness mainly depends on the test-positive rate, the frequency of postoperative pulmonary complications, and the screening costs; however, no matter how high the test-positive rate, the cost-effectiveness is poor if the probability of developing postoperative pulmonary complications among patients positive for SARS-CoV-2 is sufficiently reduced.

Association of clinical characteristics and vaccines with risk of persistently viral clearance in patients infected with SARS-CoV-2 Omicron variant in Shanghai, China

Importance

The global COVID-19 pandemic does not appear to end in the near future. Currently, limited data are available on the risk factors for delayed viral clearance in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection.

Objective

This study aimed to investigate the association of clinical characteristics and vaccination with prolonged viral clearance.

Methods

This retrospective cohort included 16,985 patients who had contracted the SARS-CoV-2 Omicron variant between April 5 and May 30, 2022, in Shanghai, China, and had mild or no symptoms. The patients were admitted to the quarantine venue at the Shanghai New International Expo Center.

Results

Of the 16,985 participants, the occurrence of viral clearance was ≤8 and > 8 days in 11,009 (64.8 %) and 5976 (35.2 %) participants, respectively. Risk factors related to patients who remained persistently polymerase chain reaction (PCR)-positive were sex (Male, odds ratio [OR] 1.221, p < 0.001), older age (35-49, OR 1.389, p < 0.001; 50-64, OR 1.659, p < 0.001; ≥65, OR 2.139, p < 0.001), presence of symptoms (OR 1.093, p = 0.030), number of vaccinations (two doses, OR 0.753, p < 0.001; three doses, OR 0.797, p < 0.001; four doses, OR 0.543, p < 0.001), and cycle threshold (Ct) value for ORF1ab gene at diagnosis (25-35, OR 0.235, p < 0.001; >35, OR 0.079, p < 0.001). The lower rates of increase in Ct values were observed in the later viral shedding group than in the early viral shedding group for ORF1ab (β = -0.791, p < 0.001) and N genes (β = -0.825, p < 0.001).

Conclusion

Prolonged SARS-CoV-2 RNA detection and higher viral concentrations were associated with factors such as male sex, older age, symptomatic status, and fewer doses of vaccination in patients admitted to Shanghai Makeshift Hospital between April 5 and May 30, 2022.

Changing genomic epidemiology of COVID-19 in long-term care facilities during the 2020-2022 pandemic, Washington State

BACKGROUND

Long-term care facilities (LTCFs) are vulnerable to disease outbreaks. Here, we jointly analyze SARS-CoV-2 genomic and paired epidemiologic data from LTCFs and surrounding communities in Washington state (WA) to assess transmission patterns during 2020-2022, in a setting of changing policy. We describe sequencing efforts and genomic epidemiologic findings across LTCFs and perform in-depth analysis in a single county.

METHODS

We assessed genomic data representativeness, built phylogenetic trees, and conducted discrete trait analysis to estimate introduction sizes over time, and explored selected outbreaks to further characterize transmission events.

RESULTS

We found that transmission dynamics among cases associated with LTCFs in WA changed over the course of the COVID-19 pandemic, with variable introduction rates into LTCFs, but decreasing amplification within LTCFs. SARS-CoV-2 lineages circulating in LTCFs were similar to those circulating in communities at the same time. Transmission between staff and residents was bi-directional.

CONCLUSIONS

Understanding transmission dynamics within and between LTCFs using genomic epidemiology on a broad scale can assist in targeting policies and prevention efforts. Tracking facility-level outbreaks can help differentiate intra-facility outbreaks from high community transmission with repeated introduction events. Based on our study findings, methods for routine tree building and overlay of epidemiologic data for hypothesis generation by public health practitioners are recommended. Discrete trait analysis added valuable insight and can be considered when representative sequencing is performed. Cluster detection tools, especially those that rely on distance thresholds, may be of more limited use given current data capture and timeliness. Importantly, we noted a decrease in data capture from LTCFs over time. Depending on goals for use of genomic data, sentinel surveillance should be increased or targeted surveillance implemented to ensure available data for analysis.

Comparison of clinical outcomes over time of inpatients with healthcare-associated or community-acquired coronavirus disease 2019 (COVID-19): A multicenter, prospective cohort study

OBJECTIVE

To compare clinical outcomes over time of inpatients with healthcare-associated coronavirus disease 2019 (HA-COVID-19) versus community-acquired COVID-19 (CA-COVID-19).

DESIGN

We conducted a multicenter, prospective observational cohort study of inpatients with COVID-19.

SETTING

The study was conducted across 16 acute-care hospitals in Switzerland.

PARTICIPANTS AND METHODS

We compared HA-COVID-19 cases, defined as patients with a positive severe acute respiratory coronavirus virus 2 (SARS-CoV-2) test > 5 days after hospital admission, with hospitalized CA-COVID-19 cases, defined as those who tested positive within 5 days of admission. The composite primary outcome was patient transfer to an intensive care unit (ICU) or an intermediate care unit (IMCU) and/or all-cause in-hospital mortality. We used cause-specific Cox regression and Fine-Gray regression to model the time to the composite clinical outcome, adjusting for confounders and accounting for the competing event of discharge from hospital. We compared our results to those from a conventional approach using an adjusted logistic regression model where time-varying effects and competitive risk were ignored.

RESULTS

Between February 19, 2020, and December 31, 2020, we included 1,337 HA-COVID-19 cases and 9,068 CA-COVID-19 cases. HA-COVID-19 patients were significantly older: median, 80 (interquartile range [IQR], 71-87) versus median 70 (IQR, 57-80) (P < .001). A greater proportion of HA-COVID-19 patients had a Charlson comorbidity index ≥ 5 (79% vs 55%; P < .001) than did CA-COVID-19 patients. In time-varying analyses, between day 0 and 8, HA-COVID-19 cases had a decreased risk of death or ICU or IMCU transfer compared to CA-COVID-19 cases (cause-specific hazard ratio [csHR], 0.43; 95% confidence interval [CI], 0.33-0.56). In contrast, from day 8 to 30, HA-COVID-19 cases had an increased risk of death or ICU or IMCU transfer (csHR, 1.49; 95% CI, 1.20-1.85), with no significant effect on the rate of discharge (csHR, 0.83; 95% CI, 0.61-1.14). In the conventional logistic regression model, HA-COVID-19 was protective against transfer to an ICU or IMCU and/or all-cause in-hospital mortality (adjusted odds ratio [aOR], 0.79, 95% CI, 0.67-0.93).

CONCLUSIONS

The risk of adverse clinical outcomes for HA-COVID-19 cases increased substantially over time in hospital and exceeded that for CA-COVID-19. Using approaches that do not account for time-varying effects or competing events may not fully capture the true risk of HA-COVID-19 compared to CA-COVID-19.

Universal masking during COVID-19 outbreaks in aged care settings: A systematic review and meta-analysis

Aged care facilities (ACF) are a high-risk COVID-19 transmission setting, and older residents are at greater risk of severe outcomes. This systematic review and meta-analysis assessed whether universal masking and COVID-19 vaccination reduce SARS-CoV-2 attack rates (ARs) in ACF. Articles published between 1 December 2019 and 28 February 2022 were screened across five databases (Medline, Embase, PubMed, Scopus, Web of Science and Cumulative Index to Nursing and Allied Health Literature (CINAHL)). Risk of bias was assessed using relevant Joanna Briggs Institute critical appraisal tools. Meta-analysis of single proportions, subgroup analysis, and meta-regression were performed to compare the effects of universal masking and vaccine doses on pooled SARS-CoV-2 ARs. Of 99 included articles, SARS-CoV-2 ARs for residents were available in 86 studies (representing 139 outbreaks), and for staff in 49 studies (78 outbreaks). Universal masking was associated with lower SARS-CoV-2 ARs in ACF outbreaks (AR = 34.9% [95% CI: 27.2-42.6%]) compared to facilities without universal masking (67.3% [54.2-80.4%], p < .0001). In ACF with universal masking prior to outbreak onset, facility-wide testing, and documentation of asymptomatic infection, the asymptomatic AR at time of testing was 11.4% (6.5-17.4%) in residents. Receipt of zero, one and two vaccination doses were associated with ARs of 64.9% (49.6-80.2%), 54.9% (33.7-76.1%) and 45.2% (29.2-61.3%), respectively. To protect residents from COVID-19, ACF should provide vaccination of residents and staff, universal masking for staff, and facility-wide testing during times of heightened community transmission.

Seroprevalence of Anti-SARS-CoV-2 Remained Extremely Low in Taiwan Until the Vaccination Program Was Implemented

Background

The Taiwanese government made a concerted effort to contain a coronavirus disease 2019 (COVID-19) nosocomial outbreak of variant B.1.429, shortly before universal vaccination program implementation. This study aimed to investigate seroprevalence in the highest-risk regions.

Methods

Between January and February 2021, we retrieved 10 000 repository serum samples from blood donors to examine for antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) and spike (S) antigens. A positive result was confirmed if anti-N and anti-S antibodies were positive. Overall, 2000 donors residing in the highest-risk district and donating blood in January 2021 were further examined for SARS-CoV-2 RNA. We estimated seroprevalence and compared the epidemic curve between confirmed COVID-19 cases and blood donors with positive antibodies or viral RNA.

Results

Twenty-one cases with COVID-19 were confirmed in the nosocomial cluster, with an incidence of 1.27/100 000 in the COVID-affected districts. Among 4888 close contacts of the nosocomial cases, 20 (0.4%) became confirmed cases during isolation. Anti-SARS-CoV-2 was detected in 2 of the 10000 blood donors, showing a seroprevalence of 2/10000 (95% CI, 0.55-7.29). None of the 2000 donors who underwent tests for SARS-CoV-2 RNA were positive. The SARS-CoV-2 infection epidemic curve was observed sporadically in blood donors compared with the nosocomial cluster.

Conclusions

In early 2021, an extremely low anti-SARS-CoV-2 seroprevalence among blood donors was observed. Epidemic control measures through precise close contact tracing, testing, and isolation effectively contained SARS-CoV-2 transmission before universal vaccination program implementation.

Nursing Home Residents' COVID-19 Infections in the United States: A Systematic Review of Personal and Contextual Factors

Background: This mixed methods systemic review synthesizes the evidence about nursing home risks for COVID-19 infections. Methods: Four electronic databases (PubMed, Web of Science, Scopus, and Sage Journals Online) were searched between January 2020 and October 2022. Inclusion criteria were studies reported on nursing home COVID-19 infection risks by geography, demography, type of nursing home, staffing and resident's health, and COVID-19 vaccination status. The Mixed Methods Appraisal Tool (MMAT) was used to assess the levels of evidence for quality, and a narrative synthesis for reporting the findings by theme. Results: Of 579 initial articles, 48 were included in the review. Findings suggest that highly populated counties and urban locations had a higher likelihood of COVID-19 infections. Larger nursing homes with a low percentage of fully vaccinated residents also had increased risks for COVID-19 infections than smaller nursing homes. Residents with advanced age, of racial minority, and those with chronic illnesses were at higher risk for COVID-19 infections. Discussion and implications: Findings suggest that along with known risk factors for COVID-19 infections, geographic and resident demographics are also important preventive care considerations. Access to COVID-19 vaccinations for vulnerable residents should be a priority.

Impact of nursing home characteristics on COVID-19 infections among residents and staff

BACKGROUND

Excess mortality occurred in nursing homes during the SARS-CoV pandemic. This study aimed to identify risk factors for COVID-19 infection and mortality in nursing home residents and staff in Hesse, Germany.

METHODS

A retrospective cohort study of 687 nursing homes was performed. We used t tests and logistic regressions to quantify the role of nursing homes' size, location, staff qualification, and room occupancy as potential risk factors.

RESULTS

The bivariate statistics show that a higher proportion of infected staff and for-profit operations were associated with an increase in infections among residents and staff, while more single rooms and registered nurses showed protective effects. Our model calculations also show that the presence of a higher ratio of registered nurses was a significant protective factor against resident infection (odds ratios [OR]: 0.969, P = .002), resident mortality (OR: 0.973, P = .006), and safeguarded staff (OR: 0.979, P = .034). In contrast, more single rooms (OR: 0.993, P = .029) were protective for residents, while increased risk factors included more beds (OR: 1.006, P = .006 for residents' infections, OR: 1.008, P < .001 for mortality) and infected staff (OR: 2.363, P < .001 for residents' infections). For staff, medium population density (OR: 2.322, P = .016) and infected residents (OR: 1.308, P < .001) were associated with elevated risk.

CONCLUSIONS

Preventing infection outbreaks among residents and staff is crucial to reduce mortality. Strategies include increasing single-occupancy rooms, improving staff qualifications, and targeting facilities with lower registered nurse ratios and single-occupancy rooms for inspection.

Human mRNA in saliva can correctly identify individuals harboring acute infection

IMPORTANCE

There are a variety of clinical and laboratory criteria available to clinicians in controlled healthcare settings to help them identify whether an infectious disease is present. However, in situations such as a new epidemic caused by an unknown infectious agent, in health screening contexts performed within communities and outside of healthcare facilities or in battlefield or potential biowarfare situations, this gets more difficult. Pathogen-agnostic methods for rapid screening and triage of large numbers of people for infection status are needed, in particular methods that might work on an easily accessible biospecimen like saliva. Here, we identify a small, core set of approximately 70 human genes whose transcripts serve as saliva-based biomarkers of infection in the human body, in a way that is agnostic to the specific pathogen causing infection.

"We are still tired": staff and administrators' experiences during the COVID-19 pandemic within California residential care facilities for older adults

BACKGROUND

Extensive research has been conducted on the impacts of the COVID-19 pandemic on long-term care workers in specialized care facilities. However, little is known about the impacts faced by facilities that provide generalized long-term support and care, such as residential care facilities for older adults (RCFs). This study describes the challenges experienced by staff and administrators of RCFs during the COVID-19 pandemic.

METHODS

An electronic questionnaire collecting data using both closed- and open-ended questions on staff experiences was sent to 5,721 unique RCF administrator emails within the state of California between June-December 2021. Email addresses were obtained from the public database of RCFs available through the California Health and Human Services Open Data Portal. Descriptive statistics were calculated on quantitative data regarding staff preparedness training, access to resources, and administrators' confidence in meeting recommended guidelines during the pandemic. Inductive thematic analysis was conducted on qualitative data regarding the confidence levels in meeting pandemic guidelines and challenges faced related to staff stress and morale.

RESULTS

A total of 150 RCF administrators across California (response rate of 2.6%) completed the survey. Over three-fourths of respondents indicated their facilities had a designated staff member to train other staff members on emergency preparedness plans and the most frequently used resources during the COVID-19 pandemic were the Department of Social Services Community Care Licensing Division (88.7%), the county health department (86.7%), and the Centers for Disease Control and Prevention (80.7%). Administrators felt least confident in their facilities' ability to maintain adequate staffing (52.0%), communication with nearby hospitals (62.1%) and communication with state and local public health officials (69.8%) during the pandemic. Three central themes emerged from the thematic analysis on staff stress and morale: (1) physical safety, mental and emotional impact of the COVID-19 pandemic; (2) staffing issues; and (3) challenges with guidelines in managing the ongoing pandemic.

CONCLUSIONS

Findings from this research study can be used to actively target training resources for facility administrators and staff that have been identified as most frequently used and relevant for emergency preparedness in these understudied facilities. Additionally, developing a better understanding of the staffing stress and morale difficulties in RCFs can provide insight on how policymakers can assist these critical facilities in better preparing for future crises.

Analysis of blood and nasal epithelial transcriptomes to identify mechanisms associated with control of SARS-CoV-2 viral load in the upper respiratory tract

OBJECTIVES

The amount of SARS-CoV-2 detected in the upper respiratory tract (URT viral load) is a key driver of transmission of infection. Current evidence suggests that mechanisms constraining URT viral load are different from those controlling lower respiratory tract viral load and disease severity. Understanding such mechanisms may help to develop treatments and vaccine strategies to reduce transmission. Combining mathematical modelling of URT viral load dynamics with transcriptome analyses we aimed to identify mechanisms controlling URT viral load.

METHODS

COVID-19 patients were recruited in Spain during the first wave of the pandemic. RNA sequencing of peripheral blood and targeted NanoString nCounter transcriptome analysis of nasal epithelium were performed and gene expression analysed in relation to paired URT viral load samples collected within 15 days of symptom onset. Proportions of major immune cells in blood were estimated from transcriptional data using computational differential estimation. Weighted correlation network analysis (adjusted for cell proportions) and fixed transcriptional repertoire analysis were used to identify associations with URT viral load, quantified as standard deviations (z-scores) from an expected trajectory over time.

RESULTS

Eighty-two subjects (50% female, median age 54 years (range 3-73)) with COVID-19 were recruited. Paired URT viral load samples were available for 16 blood transcriptome samples, and 17 respiratory epithelial transcriptome samples. Natural Killer (NK) cells were the only blood cell type significantly correlated with URT viral load z-scores (r = -0.62, P = 0.010). Twenty-four blood gene expression modules were significantly correlated with URT viral load z-score, the most significant being a module of genes connected around IFNA14 (Interferon Alpha-14) expression (r = -0.60, P = 1e-10). In fixed repertoire analysis, prostanoid-related gene expression was significantly associated with higher viral load. In nasal epithelium, only GNLY (granulysin) gene expression showed significant negative correlation with viral load.

CONCLUSIONS

Correlations between the transcriptional host response and inter-individual variations in SARS-CoV-2 URT viral load, revealed many molecular mechanisms plausibly favouring or constraining viral replication. Existing evidence corroborates many of these mechanisms, including likely roles for NK cells, granulysin, prostanoids and interferon alpha-14. Inhibition of prostanoid production and administration of interferon alpha-14 may be attractive transmission-blocking interventions.

Neutralizing Antibodies against SARS-CoV-2: Importance of Comorbidities in Health Personnel against Reinfections

One of the priority lines of action to contain the SARS-CoV-2 pandemic was vaccination programs for healthcare workers. However, with the emergence of highly contagious strains, such as the Omicron variant, it was necessary to know the serological status of health personnel to make decisions for the application of reinforcements. The aim of this work was to determine the seroprevalence against SARS-CoV-2 in healthcare workers in a Mexican hospital after six months of the administration of the Pfizer-BioNTech vaccine (two doses, 4 weeks apart) and to investigate the association between comorbidities, response to the vaccine, and reinfections. Neutralizing antibodies against SARS-CoV-2 were determined using ELISA assays for 262 employees of Hospital Juárez de México with and without a history of COVID-19. A beta regression analysis was performed to study the associated comorbidities and their relationship with the levels of antibodies against SARS-CoV-2. Finally, an epidemiological follow-up was carried out to detect reinfections in this population. A significant difference in SARS-CoV-2 seroprevalence was observed in workers with a history of COVID-19 prior to vaccination compared to those without a history of the disease (MD: 0.961 and SD: 0.049; <0.001). Beta regression showed that workers with a history of COVID-19 have greater protection compared to those without a history of the infection. Neutralizing antibodies were found to be decreased in alcoholic and diabetic subjects (80.1%). Notably, eight cases of Omicron reinfections were identified, and gender and obesity were associated with the presence of reinfections (6.41 OR; 95% BCa CI: 1.15, 105.0). The response to the vaccine was influenced by the history of SARS-CoV-2 infection and associated comorbidities. The above highlights the importance of prioritizing this segment of the population for reinforcements in periods of less than one year to guarantee their effectiveness against new variants.

The impact of SARS-CoV-2 on healthcare workers of a large University Hospital in the Veneto Region: risk of infection and clinical presentation in relation to different pandemic phases and some relevant determinants

Aim

The aim of this study is to evaluate the incidence of SARS-CoV-2 infection and the prevalence of COVID-19-related symptoms in relation to pandemic phases and some relevant variables in a cohort of 8,029 HCWs from one of the largest Italian University Hospitals.

Methods

A single-center retrospective study was performed on data collected during SARS-CoV-2 infection surveillance of HCWs. Cox's multiple regression was performed to estimate hazard ratios of SARS-CoV-2 infection. Logistic multivariate regression was used to assess the risk of asymptomatic infections and the onset of the most frequent symptoms. All analyses were adjusted for sociodemographic and occupational factors, pandemic phases, vaccination status, and previous infections.

Results

A total of 3,760 HCWs resulted positive (2.0%-18.6% across five study phases). The total incidence rate of SARS-CoV-2 infection was 7.31 cases per 10,000 person-days, significantly lower in phase 1 and higher in phases 4 and 5, compared to phase 3. Younger HCWs, healthcare personnel, and unvaccinated subjects showed a higher risk of infection. Overall, 24.5% were asymptomatic infections, with a higher probability for men, physicians, and HCWs tested for screening, fully vaccinated, and those with previous infection. The clinical presentation changed over the phases in relation to vaccination status and the emergence of new variants.

Conclusion

The screening activities of HCWs allowed for the early detection of asymptomatic cases, limiting the epidemic clusters inside the hospital wards. SARS-CoV-2 vaccination reduced infections and symptomatic cases, demonstrating again its paramount value as a preventive tool for occupational and public health.