Symptomatic Healthcare Workers Research Articles

Impact of interventions to reduce nosocomial transmission of SARS-CoV-2 in English NHS Trusts: a computational modelling study

BackgroundPrior to September 2021, 55,000–90,000 hospital inpatients in England were identified as having a potentially nosocomial SARS-CoV-2 infection. This includes cases that were likely missed due to pauci- or asymptomatic infection. Further, high numbers of healthcare workers (HCWs) are thought to have been infected, and there is evidence that some of these cases may also have been nosocomially linked, with both HCW to HCW and patient to HCW transmission being reported. From the start of the SARS-CoV-2 pandemic interventions in hospitals such as testing patients on admission and universal mask wearing were introduced to stop spread within and between patient and HCW populations, the effectiveness of which are largely unknown.Materials/methodsUsing an individual-based model of within-hospital transmission, we estimated the contribution of individual interventions (together and in combination) to the effectiveness of the overall package of interventions implemented in English hospitals during the COVID-19 pandemic. A panel of experts in infection prevention and control informed intervention choice and helped ensure the model reflected implementation in practice. Model parameters and associated uncertainty were derived using national and local data, literature review and formal elicitation of expert opinion. We simulated scenarios to explore how many nosocomial infections might have been seen in patients and HCWs if interventions had not been implemented. We simulated the time period from March-2020 to July-2022 encompassing different strains and multiple doses of vaccination.ResultsModelling results suggest that in a scenario without inpatient testing, infection prevention and control measures, and reductions in occupancy and visitors, the number of patients developing a nosocomial SARS-CoV-2 infection could have been twice as high over the course of the pandemic, and over 600,000 HCWs could have been infected in the first wave alone. Isolation of symptomatic HCWs and universal masking by HCWs were the most effective interventions for preventing infections in both patient and HCW populations. Model findings suggest that collectively the interventions introduced over the SARS-CoV-2 pandemic in England averted 400,000 (240,000 – 500,000) infections in inpatients and 410,000 (370,000 – 450,000) HCW infections.ConclusionsInterventions to reduce the spread of nosocomial infections have varying impact, but the package of interventions implemented in England significantly reduced nosocomial transmission to both patients and HCWs over the SARS-CoV-2 pandemic.

Rapid Decline of SARS-CoV-2 Viral Load in Single vs. Double-Dose (Short-Interval

The present work was carried out during the emergence of Delta Variant of Concern (VoC) and aimed to study the change in SARS CoV-2 viral load in Covishield vaccinated asymptomatic/mildly symptomatic health-care workers (HCWs) to find out the optimum isolation period. The SARS CoV-2 viral load was carried out in sequential samples of 55 eligible HCWs which included unvaccinated (UnV; n = 11), single-dose vaccinated (SDV, n = 20) and double-dose vaccinated [DDV, n = 24; short-interval (<6weeks)] subjects. The mean load of envelope (E) gene on day 5 in SDV [0.42 × 105 copies/reaction] was significantly lower as compared to DDV [6.3 × 105 copies/reaction, P = 0.005] and UnV [6.6 × 105 copies/reaction, P = 0.001] groups. The rate of decline of SARS CoV-2 viral load in the initial 5days of PCR positivity was significantly higher in SDV as compared to that in DDV (Mean log decline 0.39 vs. 0.19; P < 0.001). This was possibly due to interference of adenoviral immunity of first dose of adenovirus-vectored vaccine in double-dose vaccinated HCWs who had received vaccines within a shorter interval (<6weeks).

COVID-19 Pozitif Sağlık Çalışanlarının Semptom, Laboratuvar ve Toraks Bilgisayarlı Tomografi Bulgularının Değerlendirilmesi: Rektrospektif Çalışma

Objective: The study was carried out to examine the symptoms and laboratory and thoracic computed tomography findings of COVID-19-positive healthcare professionals in northeastern Turkey. &#x0D; Material and Method: The sample of this descriptive, cross-sectional, and retrospective study consisted of 146 healthcare professionals who had positive COVID-19. Data were collected using electronic data from the hospital information management system and the personal health records of healthcare professionals. &#x0D; Results: 50.6% of COVID-19-positive healthcare professionals were symptomatic, 49.4% were asymptomatic, 52.7% of nurses, midwives, and health officers, and those who were symptomatic experienced the most cough, muscle-joint pain, and fatigue. Healthcare workers had a high leukocyte, neutrophil, lymphocyte, platelet mean, C reactive protein, and D-dimer, and 24.1% had COVID-19-compatible thorax computed tomography. Symptomatic healthcare professionals had a lower median of leukocyte and a higher median of C reactive protein and procalcitonin compared to asymptomatic healthcare professionals. Healthcare professionals with COVID-19 compatible thorax computed tomography had a lower leukocyte, median, and platelet mean, lower high C reactive protein median, and higher D-dimer median. &#x0D; Conclusion: The study found that half of the healthcare professionals are symptomatic, and leukocyte, neutrophil, lymphocyte, C reactive protein, and platelet values affect the development of COVID-19-compatible thoracic computed tomography. The results can be used as a knowledge base for research and by health workers and institutional authorities to implement methods to improve prevention levels.

Test negative case–control study of COVID-19 vaccine effectiveness for symptomatic SARS-CoV-2 infection among healthcare workers: Zambia, 2021–2022

ObjectivesThe study aim was to evaluate vaccine effectiveness (VE) of COVID-19 vaccines in preventing symptomatic COVID-19 among healthcare workers (HCWs) in Zambia. We sought to answer the question, ‘What is...

Prevalence, Clinical Characteristics and Outcome of COVID-19 Infection among Healthcare Workers: A Retrospective Analysis in a Single Northwest Malaysia Specialist Centre

Healthcare workers (HCWs) are most susceptible to COVID-19 because they are constantly exposed to the source. This study aimed to determine the prevalence, clinical characteristics, and outcome of healthcare workers (HCWs) with positive COVID-19 in a single institution in northwest Malaysia. Data log of HCWs diagnosed with positive COVID-19 with real-time reverse transcription-polymerase chain reaction (RT-PCR) between 1st January 2021 and 31st December 2021 in Hospital Tuanku Fauziah, Perlis, Malaysia was retrospectively analysed. A total of 198 HCWs were included. Majority were female (72.2%), mean age of 39.9 + 6.55 years, Malay (96%), nurses (46%), without co-morbidities (92.4%) and had completed two doses of COVID-19 vaccination (97%). A total of 115 HCWs contracted the infection from the community, whereas 65 HCWs may be infected from the workplace. Most of the staff were symptomatic (84.3%). Fever (49%), sore throat (40.4%), cough (33.8%) and runny nose/nasal congestion (22.2%) are the most prominent symptoms. A total of 82.8% of HCWs were diagnosed with stage 2 COVID-19. The median length of infection to occur was approximately 5 months after two doses of vaccination. Majority were manageable at home during diagnosis (76.2%), with no deaths were recorded. Symptomatic HCWs had significantly longer interval of COVID-19 vaccination-to-infection period (p&lt;0.001). The HCWs diagnosed with stage two COVID-19 had significantly longer interval of COVID-19 vaccination-to-infection as compared to stage one COVID-19 (p=0.012). Periodic evaluation of COVID-19 infection among HCWs is essential for the development of effective mitigation strategies for optimal pandemic control as well as for HCWs protection during the endemic phase.

Reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay as a rapid molecular diagnostic tool for COVID-19 in healthcare workers

In December 2019, the Chinese Center for Disease Control (CDC of China) reported an outbreak of pneumonia in the city of Wuhan (Hubei province, China) that haunted the world, resulting in a global pandemic. This outbreak was caused by a betacoronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several of these cases have been observed in healthcare professionals working in hospitals and providing care on the pandemic's frontline. In the present study, nasopharyngeal swab samples of healthcare workers were used to assess the performance of the reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay and subsequently compared with the real‐time reverse-transcription quantitative PCR (RT-qPCR) method. Thus, in this study, we validated a method for detecting SARS-CoV-2 based on RT-LAMP that can be used to diagnose these workers. The methodology used was based on analyzing the sensitivity, specificity, evaluation of the detection limit, and cross-reaction with other respiratory viruses. The agreement was estimated using a dispersion diagram designed using the Bland-Altman method. A total of 100 clinical specimens of nasopharyngeal swabs were collected from symptomatic and asymptomatic healthcare workers in Pelotas, Brazil, during the SARS-CoV-2 outbreak. RT-LAMP assay, it was possible to detect SARS-CoV-2 in 96.7% of the healthcare professionals tested using the E gene and N gene primers approximately and 100% for the gene of human β-actin. The observed agreement was considered excellent for the primer set of the E and N genes (k = 0.957 and k = 0.896), respectively. The sensitivity of the RT-LAMP assay was positive for the primer set of the E gene, detected to approximately 2 copies per reaction. For the primer set of the N gene, the assay was possible to verify an LoD of approximately 253 copies per reaction. After executing the RT-LAMP assay, no positive reactions were observed for any of the virus respiratory tested. Therefore, we conclude that RT-LAMP is effective for rapid molecular diagnosis during the COVID-19 outbreak period in healthcare professionals.

Assessment of the Occupational Risk of Tuberculosis & Air Borne Infection Control in High-Risk Hospital Wards and Its Implications on Healthcare Workers in a Tertiary Care Hospital in South India.

Introduction The indoor air in hospitals could play a significant role in the transmission of a wide array of infections, especially in respiratory intensive care units, pulmonary outpatient departments, and other areas. Unprotected coughing and sneezing may facilitate the release of aerosols and contaminate the indoor environment. The majority of infections transmitted through these modes include viral diseases, including tuberculosis (TB), influenza, and measles, among several others. Moreover, the possibility of direct and indirect transmission of microbes by air has been underestimated in hospital settings, especially in developing countries. This studytherefore was carried out to assess the burden of microbes in the air of selected wards in a tertiary care hospital and evaluate the occupational risk of some infections among healthcare workers (HCWs). Methods This study was carried out between September 2019 and February 2021 at a tertiary care teaching hospital in South India. A total of 30 symptomatic healthcare workers (HCWs) were included in the study and were screened for present and past tuberculosis (TB) as well as other lower respiratory tract infections. A tuberculin skin test, chest X-ray, and sputum acid-fast staining were performed on all the HCWs who were negative for other bacterial infections and were symptomatic. The study was conductedin coordination with the pulmonology department. Active monitoring of air was performed by microbiological air sampler in the respiratory intensive care unit (RICU) and other high-risk areas including the pulmonology outpatient department (OPD), the radiology OPD, and the microbiology department. Results Sputum for tuberculousbacteriawas positive in four (16.6%) HCWs. The chest X-ray showed radiological findings suggestive of TB in five (20.8%) HCWs. Three (12.5%) HCWs who were screened for extrapulmonary TBrevealed one (33.3%) was positive for TB of the hip joint. Among the HCWs, eight (33%) returned positive tuberculin tests. Assessment of the hospital air in theRICU revealedthe bacterial count (288 CFU/m3) exceeded the normal limit (≤50 CFU/m3). The COVID-19 isolation ward showed the lowest bacterial count (06 CFU/m3) and no fungi. The predominant bacterial isolates were gram-positive cocci in clusters (Methicillin-sensitive Staphylococcus aureus). After proper disinfection and correction of ventilation techniques, the resampling results noted microbial colonies under normal limits. Conclusion A high burden of TB was noted among the HCWs. The airborne infection control strategies are essential to minimize the risk ofnosocomial infections and occupational TB risk to HCWs. Most microbes are transmitted through the airborne route and therefore it is extremely important to take measures to control the transmission of such pathogens in hospital settings.

COVID-19 and health care worker exposure at Chris Hani Baragwanath Academic Hospital

Abstract Background: Health care workers (HCWs) are at increased risk of coronavirus disease 2019 (COVID-19). Appropriate risk assessments and testing are essential to reduce transmission and avoid workforce depletion. Objective: To investigate the risk of COVID-19 infection among HCWs who fulfil the person under investigation case definition or had exposure to a confirmed COVID-19 contact. Methods: We conducted a retrospective review of HCWs who were exposed to and/or tested for COVID-19 during the first wave of the pandemic. Data collected included demographics, exposure type, risk level, and COVID-19 test result. Frequency distribution tables, bivariate analyses, univariate and multivariate analyses were conducted. Results: Among the 1111 HCWs reviewed, 643 were tested with 35.6% positive results. PUI's accounted for 62.4% of positive cases. Symptomatic HCWs with no known contact were at a greater risk of infection than those with a patient exposure (p═0.001). The risk of testing positive was higher after a patient exposure (p═0.000) compared to a co-worker contact. Patient-facing designations had a higher risk of SARS-CoV-2 infection than non-clinical designations (p═0.013). The exception to this was security personnel who were 28 times more likely to test positive than any other designation (p═0.000). Conclusion: There is a higher positivity rate among HCWs than the general population. The presence of symptoms warrants testing. Nosocomial transmission was derived from patients more than co-worker contacts. Precautions in the workplace need to be reinforced to protect the health and safety of HCWs during this pandemic. These findings should assist with preparedness for future pandemics.

1218. Genotypic Investigation of a Rotavirus Cluster at a Pediatric Hospital in 2022

Abstract Background Rotavirus group A (RVA) was the most common cause of infectious gastroenteritis among young children before introduction of rotavirus vaccine in the United States in 2006. Following widespread vaccination, U.S. hospital acquired (HA) rotavirus cases are rare. We describe a cluster of rotavirus infections in a pediatric hospital with a genotype uncommon among U.S. children. Methods Patient cases of HA gastrointestinal (GI) illness were detected through hospital-wide microbiology surveillance, performed by Infection Prevention and Control (IPC) practitioners per state requirements. Cluster procedures were implemented on a unit when 3 cases were identified by symptoms and/or laboratory tests within 48 hours. Due to the current rarity of rotavirus clusters, the hospital partnered with Centers for Disease Control and Prevention (CDC) laboratories to sequence strains in addition to instituting local control measures. RVA strains were genotyped by using the genotype specific qRT-PCR assays for VP7 and VP4 genes. Next Generation Sequencing (NGS) was performed for RVA strain characterization on Illumina MiSeq. Genotypes for all 10 RVA were determined by NCBI’s BLASTN program. Results Epidemiologic surveillance identified a rotavirus cluster of 10 patients aged 10 months to 10 years old, of whom 50% had received rotavirus vaccine. Symptoms included emesis and diarrhea. Cases could not be attributed to vaccine related shedding. All patients had epidemiologic links by contiguous bed spaces or shared care teams. Sequencing was conclusive for 9 of the 10 stool samples to be a G9P[4] genotype, which is rarely detected amongst U.S. children. Local control measures of increased education and cleaning, isolation of positive patients in single rooms, use of soap and water instead of alcohol-based hand sanitizer on room exit, and furlough of symptomatic healthcare workers halted transmission. Conclusion Routine surveillance of HA GI illness identified a cluster; RVA strain genotyping and characterization identified unusual rotavirus genotype G9P[4] as the cause. Partnership between IPC practitioners and laboratorians with CDC demonstrated the need to enhance infection prevention measures to halt transmission and identified a rare rotavirus strain as the likely cause of the cluster. Disclosures Courtney E. Comar, PhD, Pfizer: Stocks/Bonds|Viatris: Stocks/Bonds.

311. Modeling Diagnostic Testing Strategies for SARS-CoV-2 to Minimize Societal Costs and Return People to Work

Abstract Background The shift to more transmissible but less virulent strains of SARS-CoV-2 has altered the risk calculation for infection. Particularly among young adults, the economic burden of lost work due to isolation exceeds the economic burden of morbidity due to infection. Testing strategies must adapt to these changing circumstances. Methods We modeled six testing strategies to estimate total societal costs for symptomatic people 18-49 years old: isolation of all individuals with no testing, rapid antigen test (RAg), RAg followed by a second RAg 48h later if first negative, RAg followed by a polymerase chain reaction (PCR) if negative, RAg followed by a PCR if positive, and PCR alone. We calculated costs for hypothetical cohorts of 100 symptomatic healthcare workers tested with each strategy; we included testing costs, lost wages, and hospitalization costs for the index, secondary, and tertiary cases. Key assumptions were 5% prevalence of infection, sensitivity of first/second RAg 40/80% with 97% specificity, PCR sensitivity/specificity 95/99%, all individuals isolate at symptom onset, are tested the same day, and isolate for 5 days if positive. RAg results were available the same day, PCR results were available the next day (Figure 1). One-way sensitivity analyses were performed for RAg sensitivity (20-80%) and positivity rate (1-80%). Results The least expensive strategy was RAg alone (Figure 2). This was primarily driven by its low sensitivity, which reduced lost wages at the expense of missing cases. At a threshold for RAg sensitivity lower than 29%, PCR testing alone became the cheapest strategy. When the positivity rate was &amp;gt; 6% confirming a negative RAg with a PCR became the cheapest strategy, closely followed by PCR alone. At a positivity rate of &amp;gt; 29%, isolation without testing was cheapest followed by confirming a negative RAg with a PCR and by the serial RAg test strategies (Figure 3). Conclusion In relatively young, healthy populations, a single rapid test was the least expensive strategy when the positivity rate was &amp;lt; 6%, testing that included PCR became cheapest at intermediate positivity, and empiric isolation was cheapest at positivity &amp;gt; 29%. Calibrating SARS-CoV-2 test strategies based on epidemiology may save societal costs. Disclosures Nicholas A. Turner, MD, MHSc, Aperio: Advisor/Consultant.

Experience with SARS-CoV-2 in an orthopaedic hospital

Concerns about nosocomial transmission of SARS-CoV-2 have been described since the COVID-19 pandemic was first reported and cases of hospital-acquired (HA) COVID-19 and COVID-19 outbreaks have been reported even in clinical areas not intended for the specific care of COVID-19 and declared as "non-COVID" areas. Retrospective analysis of measures to prevent of hospital acquisition of COVID-19 in patients admitted to a tertiary referral specialist orthopaedic hospital in Brazil in which emergency care was maintained during the pandemic. The proportion of HA-COVID-19 (0.07%) was lower than the value reported for general healthcare in Brazil (0.72%, P<0.001). The integration of several clinical teams to maintain a constant surveillance system, as well as the immediate isolation of patients with any compatible symptoms of COVID-19 and the restriction from work and the testing of symptomatic healthcare workers, were an important part of the strategies adopted. We suggest that the described strategies for preventing the nosocomial spread of SARS-CoV-2 contributed to the observed proportion of HA-COVID-19 to be significantly lower than the reported national value. Future studies that investigate these and other preventative measures are important so that hospitals are prepared for further periods of a high incidence of COVID-19, as well as for other epidemics associated with respiratory transmission.

Physical, Psychological, and Cognitive Profile of Post-COVID Conditions in Healthcare Workers, Quebec, Canada.

BackgroundThe prevalence of post-COVID conditions (PCC) and associated physical, psychological, and cognitive symptoms was assessed among Quebec healthcare workers (HCWs) with coronavirus disease 2019 (COVID-19).MethodsThis case-control study compared 6061 symptomatic HCWs with polymerase chain reaction–confirmed COVID-19 between July 2020 and May 2021 with a random sample of 4390 symptomatic HCWs who were test-negative controls. The prevalence of physical symptoms lasting ≥4 weeks (PCC4w) or ≥12 weeks (PCC12w) was estimated among hospitalized and nonhospitalized cases. In multivariate models, sociodemographic and clinical characteristics, as well as vaccine history, were evaluated as potential risk factors. Prevalence ratios compared 4 aspects of self-reported cognitive dysfunction among PCC cases to controls, adjusting for psychological distress and fatigue.ResultsPCC4w and PCC12w prevalences of 46% (2746/5943) and 40% (653/1746), respectively, were observed among nonhospitalized cases and 76% (90/118) and 68% (27/37), respectively, among hospitalized cases. Hospitalization, female sex, and age were associated with higher PCC risk. A substantial proportion of nonhospitalized PCC4w cases often or very often reported cognitive dysfunction, including concentration (33%) or organizing (23%) difficulties, forgetfulness (20%), and loss of necessary items (10%). All 4 aspects of cognitive dysfunction were associated with PCC4w symptoms, psychological distress, and fatigue.ConclusionsPCC may be a frequent sequela of ambulatory COVID-19 in working-age adults, with important effects on cognition. With so many HCWs infected, the implications for quality healthcare delivery could be profound if cognitive dysfunction and other severe PCC symptoms persist in a professionally disabling way. Further evaluation of PCC prevalence and prognosis is warranted.

Protective effect conferred by prior infection and vaccination on COVID-19 in a healthcare worker cohort in South India.

The emergence of newer variants with the immune escape potential raises concerns about breakthroughs and re-infections resulting in future waves of infection. We examined the protective effect of prior COVID-19 disease and vaccination on infection rates among a cohort of healthcare workers (HCW) in South India during the second wave driven mainly by the delta variant. Symptomatic HCWs were routinely tested by RT-PCR as per institutional policy. Vaccination was offered to all HCWs in late January, and the details were documented. We set up a non-concurrent cohort to document infection rates and estimated protective efficacy of prior infection and vaccination between 16th Apr to 31st May 2021, using a Cox proportional hazards model with time-varying covariates adjusting for daily incidence. Between June 2020 and May 2021, 2735 (23.9%) of 11,405 HCWs were infected, with 1412, including 32 re-infections, reported during the second wave. 6863 HCWs received two doses of vaccine and 1905 one dose. The protective efficacy of prior infection against symptomatic infection was 86.0% (95% CI 76.7%-91.6%). Vaccination combined with prior infection provided 91.1% (95% CI 84.1%-94.9%) efficacy. In the absence of prior infection, vaccine efficacy against symptomatic infection during the second wave was 31.8% (95% CI 23.5%- 39.1%). Prior infection provided substantial protection against symptomatic re-infection and severe disease during a delta variant driven second wave in a cohort of health care workers.

SARS-CoV-2 Omicron Symptomatic Infections in Previously Infected or Vaccinated South African Healthcare Workers.

We investigated Omicron infections among healthcare workers (HCW) presenting with symptoms of SARS-CoV-2 infection and evaluated the protective effect of vaccination or prior infection. Between 24 November and 31 December 2021, HCW in Johannesburg, South Africa, were tested for SARS-CoV-2 infection by Nucleic Acid Amplification Test (NAAT). Blood samples collected either at the symptomatic visit or in the 3 months prior, were tested for spike protein immunoglobulin G (IgG). Overall, 433 symptomatic HCW were included in the analysis, with 190 (43.9%) having an Omicron infection; 69 (16.7%) were unvaccinated and 270 (62.4%) received a single dose of the Ad26.COV.2 vaccine. There was no difference in the odds of identifying Omicron between unvaccinated and Ad26.COV.2 vaccinated HCW (adjusted odds ratio (aOR) 0.81, 95% confidence interval (CI): 0.46, 1.43). One-hundred and fifty-four (35.3%) HCW had at least one SARS-CoV-2 NAAT-confirmed prior infection; these had lower odds of Omicron infection compared with those without past infection (aOR 0.55, 95%CI: 0.36, 0.84). Anti-spike IgG concentration of 1549 binding antibody unit/mL was suggestive of significant reduction in the risk of symptomatic Omicron infection. We found high reinfection and vaccine breakthrough infection rates with the Omicron variant among HCW. Prior infection and high anti-spike IgG concentration were protective against Omicron infection.

Real World Performance of SARS-CoV-2 Antigen Rapid Diagnostic Tests in Various Clinical Settings.

To assess the validity of Antigen rapid diagnostic tests (Ag-RDT) for SARS-CoV-2 as decision support tool in various hospital-based clinical settings. Retrospective cohort study among symptomatic and asymptomatic patients and Healthcare workers (HCW). A large tertiary teaching medical center serving as a major COVID-19 hospitalizing facility. Ag-RDTs' performance was assessed in three clinical settings: 1. Symptomatic patients and HCW presenting at the Emergency Departments 2. Asymptomatic patients screened upon hospitalization 3. HCW of all sectors tested at the HCW clinic following exposure. We obtained 5172 samples from 4595 individuals, who had both Ag-RDT and quantitative real-time PCR (qRT-PCR) results available. Of these, 485 samples were positive by qRT-PCR. The positive percent agreement (PPA) of Ag-RDT was greater for lower cycle threshold (Ct) values, reaching 93% in cases where Ct-value was <25 and 85% where Ct-value was <30. PPA was similar between symptomatic and asymptomatic individuals. We observed a significant correlation between Ct-value and time from infection onset (p<0.001). Ag-RDT are highly sensitive to the infectious stage of COVID-19 manifested by either high viral load (lower Ct) or proximity to infection, whether patient is symptomatic or asymptomatic. Thus, this simple-to-use and inexpensive detection method can be used as a decision support tool in various in-hospital clinical settings, assisting patient flow and maintaining sufficient hospital staffing.

Comparative Analysis of Circulating Levels of SARS-CoV-2 Antibodies and Inflammatory Mediators in Healthcare Workers and COVID-19 Patients.

Advances in knowledge of the pathophysiology of COVID-19 have been acquired; however, the host factors that could explain the mild and severe forms of the disease are not fully understood. Thus, we proposed to evaluate anti-SARS-CoV-2 antibodies and the inflammatory response of different groups of individuals, including healthcare workers (HCW), sick and dead COVID-19 patients and also recovered patients to contribute to this knowledge gap. Our objective is to relate the clinical evolution of these individuals with the level of detection and functionality of specific antibodies and with the production of inflammatory mediators. As main findings, IgA and IgG anti-SARS-CoV-2 were detected in asymptomatic HCW. IFN-γ and TNF-α levels were higher in symptomatic HCWs than patients with COVID-19 and those who died. Patients who died had higher levels of IL-6, IL-10, and CCL2/MCP-1. We found an imbalance between antiviral and pro-inflammatory mediators in the groups, in which IFN-γ and TNF-α seem to be more associated with protection and IL-6 and CCL2/MCP-1 with pathology. Our work is pioneering the Brazilian population and corroborates data from people from other countries.

Longitudinal Monitoring of Seroconversion Status in SARS-CoV-2 RT-PCR Positive Healthcare Workers

The impact of the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome 2 (SARS-CoV-2) still continues. The duration of the immune response in individuals recovering from COVID-19 and its protection against future SARS-CoV-2 infection are not fully understood. This study aimed to longitudinally evaluate anti-SARS-CoV-2 seroconversion status in healthcare workers with positive SARS-CoV-2 Real-time reverse transcription polymerase chain reaction (rRT-PCR), test in Mersin University Hospital. A total of 68 healthcare workers with positive SARS-CoV-2 rRT-PCR test between 19 April and 27 November 2020 were included in the study. Blood samples were collected from healthcare workers for SARS-CoV-2 antibody testing in the 1st, 3rd and 5th months following PCR positivity. Healthcare workers were classified as symptomatic, asymptomatic and reinfected according to their clinical findings, and rRT-PCR cycle thresholds (Ct) were recorded. Elecsys Anti-SARS-CoV-2 (Roche Diagnostics, Germany) kit was used for antibody testing. Of the 68 healthcare workers; 46 were classified as symptomatic, 15 as asymptomatic, and seven as reinfected. Twenty-seven (39.7%) of the healthcare workers were male and 41 (60.3%) were female, and the mean age was 36.4 ± 9.04. Seroconversion was detected in 45 (66.2%) of 68 healthcare workers in the study, and only one person had sero-negative result at the end of the 5th month. While seroconversion was detected in 78.3% (n= 36/46) of symptomatic healthcare workers, it was observed in 26.7% (n= 4/15) of the asymptomatic healthcare workers. Seroconversion was detected in only one of the seven reinfected healthcare workers after primary infection. After reinfection, seroconversion was observed in five of seven reinfected healthcare workers. Antibody response was not detected in two of them after both infections. According to the rRT-PCR Ct values; the median of Ct value was found significantly lower in healthcare workers with seroconversion (23.26, IQR= 18.45-27.30), than the ones without seroconversion (36.20, IQR= 33.09-37.56) (p< 0.001). In those who had reinfection, the mean Ct value (31.77 ± 6.62) detected during the primary infection period was statistically higher than the Ct value (22.44 ± 5.54) detected during reinfection (p= 0.008). The most frequently recorded symptoms in healthcare workers were myalgia (57.3%), fatigue (51.5%), headache (51.5%) followed by sore throat (36.7%), fever (33.8%), cough (27.9%), diarrhea (23.5%) and dyspnea (16.2%). In addition, fever (52%) and fatigue (80.6%) were found to be significantly higher in seroconversion-positive healthcare workers than in those without seroconversion (p= 0.028; p= 0.005, respectively). As a result, a higher rate of antibody response was detected in healthcare workers who had symptomatic infection than those who were asymptomatic. It has been observed that patients with asymptomatic primary infection and without antibody response were more susceptible to reinfection. In addition, it was observed that the probability of immune response increased when the viral load increased (Ct value decreased) in symptomatic infections. Although these findings provide important information about the short-term seroconversion status of healthcare personnel; longer-term and larger-scale studies are needed to evaluate the long-term effectiveness of seroconversion and to better understand the effectiveness of the immune response developed after SARS-CoV-2 vaccine administrations.

Optimal strategies to screen health care workers for COVID-19 in the US: a cost-effectiveness analysis

BackgroundTransmission of SARS-CoV-2 in health care facilities poses a challenge against pandemic control. Health care workers (HCWs) have frequent and high-risk interactions with COVID-19 patients. We undertook a cost-effectiveness analysis to determine optimal testing strategies for screening HCWs to inform strategic decision-making in health care settings.MethodsWe modeled the number of new infections, quality-adjusted life years lost, and net costs related to six testing strategies including no test. We applied our model to four strata of HCWs, defined by the presence and timing of symptoms. We conducted sensitivity analyses to account for uncertainty in inputs.ResultsWhen screening recently symptomatic HCWs, conducting only a PCR test is preferable; it saves costs and improves health outcomes in the first week post-symptom onset, and costs $83,000 per quality-adjusted life year gained in the second week post-symptom onset. When screening HCWs in the late clinical disease stage, none of the testing approaches is cost-effective and thus no testing is preferable, yielding $11 and 0.003 new infections per 10 HCWs. For screening asymptomatic HCWs, antigen testing is preferable to PCR testing due to its lower cost.ConclusionsBoth PCR and antigen testing are beneficial strategies to identify infected HCWs and reduce transmission of SARS-CoV-2 in health care settings. IgG tests’ value depends on test timing and immunity characteristics, however it is not cost-effective in a low prevalence setting. As the context of the pandemic evolves, our study provides insight to health-care decision makers to keep the health care workforce safe and transmissions low.

Antibody responses after two doses of CoronaVac of the participants with or without the diagnosis of COVID-19

BackgroundCoronaVac, an inactivated whole-virion vaccine against COVID-19, has been shown to be safe with acceptable antibody responses by various clinical trials.AimsThe objective was to investigate the post-vaccination antibody levels of both symptomatic and asymptomatic healthcare workers with or without the diagnosis of COVID-19 in an emergency department (ED) of a hospital serving as a pandemic hospital.MethodsThis single-centred, prospective study was conducted on 86 participants who were working as nurse or doctor in the ED. The volunteers were older than 18 years and either positive or negative for either computed tomography (CT), real-time reverse transcription polymerase chain reaction (qRT-PCR), or both. Thirty days after the second dose of CoronaVac (3 µg), the antibody levels were chemiluminescent microparticle immunoassay.ResultsMean age of all participants were 33.1 ± 9.1 years. The antibody levels in the qRT-PCR( +) and CT( +) groups were significantly higher than the qRT-PCR( −) and CT( −) groups, respectively (p < 0.05). In the CT( +)/qRT-PCR( +) group, the antibody level was significantly higher than the CT( −)/qRT-PCR( −) and CT( −)/qRT-PCR( +) or CT( +)/qRT-PCR( −) group (p < 0.05). On the other hand, antibody levels in the hospitalized group were significantly higher than in the non-hospitalized group (p < 0.05). A significant positive correlation was observed between the time elapsed after vaccination and antibody levels of the participants (r = 0.343; p = 0.000).ConclusionIn conclusion, antibody responses of recovered patients COVID-19 diagnosed by both CT and qRT-PCR were much robust than the patients diagnosed by either one of the techniques or undiagnosed/disease-free participants suggesting that severity of the disease likely contributes to the antibody responses after vaccination with CoronaVac.

Covid-19 presentation among symptomatic healthcare workers in Ireland:a case control study

Covid-19 presentation among symptomatic healthcare workers in Ireland:a case control study