Seroprevalence Study and Cross-Sectional Survey on COVID-19 for a Plan to Reopen the University of Alicante (Spain)

Seroprevalence against SARS-CoV-2 after booster vaccination in a prison in Alicante (Spain)

Background

Confinement conditions in prison communities are associated with increased susceptibility to infectious outbreaks. The COVID-19 pandemic has been characterized by high transmissibility and clinical severity resulting in a high number of infections and deaths worldwide. Vaccination has been a crucial tool in mitigating its devastating effects. The aim of this study is to asses the prevalence of antibodies against the Spike protein of SARS-CoV-2 in vaccinated prisoners and staff at a specific prison in Alicante.

Methods

A cross-sectional epidemiological study was designed for the population in scope using a rapid lateral flow immunochromatography serological test, conducted on July 27, 2023. Demographic and clinical variables were collected through a questionnaire. Statistical analysis was performed using the SPSS 29.0 software.

Results

A total of 560 people participated in the study; the predominant profile was men (77.3%) with an average age of 45.7 years. 71.4% of subjects were prisoners and 28.6% were prison staff. Regarding the detection of anti-SARS-CoV-2 antibodies obtained through serological test, 60.9% of the sample gave a positive result. 69.1% of participants received the last dose in 2022 or later and 62.2% received booster doses. The vaccines administered in the last dose were Biontech/Pfizer and Moderna in 88.6% of the cases. 59.5% of sample had suffered from COVID-19 and 67.0% did not have any clinical comorbidity. In the regression analysis, it was observed that the variables with a stronger statistical relationship with presence of anti-SARS-CoV-2 antibodies were: the number of years since last vaccine dose was received (aOR: 0.08; 95%CI: 0.05; 0.16) the number of vaccine doses received (aOR: 4.8; 95%CI: 2.9; 8.0) and presenting any comorbidity (aOR: 4.3; 95%CI: 2.4; 8.0). The staff received more booster doses and obtained a better response to seropositivity, with 72.5% of anti-SARS-CoV-2 result positive while prisoners reached 56.3%.

Conclusion

The COVID-19 vaccination status within the prison community following the initiation of primary immunization and subsequent booster doses, shows a low immunization coverage (60.9%), which is below expectations given the immunization strategies implemented since the start of the pandemic. There are notable differences in vaccination rates between prison staff and prisoners. These disparities are concerning, and authorities responsible for prison public health should take a more proactive approach to ensuring vaccination among prisoners.

SARS-CoV-2 wastewater surveillance at two university campuses: lessons learned and insights on intervention strategies for public health guidance

Wastewater surveillance has been a tool for public health officials throughout the COVID-19 pandemic. Universities established pandemic response committees to facilitate safe learning for students, faculty, and staff. These committees met to analyze both wastewater and clinical data to propose mitigation strategies to limit the spread of COVID-19. This paper reviews the initial efforts of utilizing campus data inclusive of wastewater surveillance for SARS-CoV-2 RNA concentrations, clinical case data from university response teams, and mitigation strategies from Grand Valley State University in West Michigan (population 21,648 students) and Oakland University in East Michigan (population 18,552 students) from November 2020 to April 2022. Wastewater positivity rates for both universities ranged from 32.8 to 46.8%. Peak viral signals for both universities directly corresponded to variant points of entry within the campus populations from 2021 to 2022. It was found that the organization of clinical case data and variability of wastewater testing data were large barriers for both universities to effectively understand disease dynamics within the university population. We review the initial efforts of onboarding wastewater surveillance and provide direction for structuring ongoing surveillance workflows and future epidemic response strategies based on those that led to reduced viral signals in campus wastewater.

Prevalence of neutralizing antibodies against SARS-CoV-2 using a rapid serological test in health workers of a Spanish Department of Health in Alicante (Spain) before the booster dose of the vaccine

AIM

To study the prevalence of neutralizing antibodies in healthcare workers and healthcare support personnel after the administration of the second dose of the BNT162b2 vaccine (Pfizer-BioNTech).

MATERIALS AND METHODS

In December 2021, we undertook a study in the Health Department in Orihuela, Alicante (Spain), which consists of 1500 workers. We collected demographic variables about the study participants, and we performed a "point-of-care" immunochromatography test to measure the presence of neutralizing antibodies (OJABIO® SARS-CoV-2 Neutralizing Antibody Detection Kit, manufactured by Wenzhou OJA Biotechnology Co., Ltd. Wenzhou, Zhejiang, China) before the administration of the third dose of the vaccine.

RESULTS

We obtained complete information about 964 (64%) workers, which consisted of 290 men and 674 women. The average age was 45,8 years (min. 18, max. 68) and the average time since the last dose of the vaccine was 40,5 weeks (min. 1,71, max. 47,71). A total of 131 participants (13,5%) had suffered infection by SARS-CoV-2 confirmed using RT-PCR. The proportion of participants who showed presence of neutralizing antibodies was 38,5%. In the multivariable analysis, the time since the last dose of the vaccine (aOR week: 1,07; 95%CI: 1,04; 1,09) and previous infection by SARS-CoV-2 (aOR: 3,7; 95CI: 2,39; 5,63) showed a statistically significant association with the presence of neutralizing antibodies.

CONCLUSIONS

The time since the administration of the last dose of the vaccine and the previous infection by SARS-CoV-2 determined the presence of neutralizing antibodies in 38,5% of the healthcare workers and support workers.

Egoavil C, Chavarría-Alarcón E, Caballero P, Tuells J. [COVID-19 vaccination at the University of Alicante (Spain): detection of neutralizing antibodies against SARS-CoV-2 by rapid serological test, a cross-sectional study]

OBJECTIVE

Neutralizing antibodies against SARS-CoV-2 have shown to be an effective tool for the analysis of the immunity generated against COVID-19. Numerous seroprevalence studies carried out in different groups have made it possible to draw a global map of vaccination coverage through the use of rapid lateral flow immunochromatography serological tests for clinical and epidemiological purposes. The objective of our study was to determine the degree of immunity against SARS-CoV-2 associated with the presence of neutralizing antibodies in administrative staff, teachers and students at the University of Alicante by means of a rapid serological test and to learn about their experience with vaccination against COVID-19.

METHODS

A cross-sectional epidemiological study was designed, based on the prevalence of antibodies against the S protein (spike) of SARS-CoV-2. A total of 888 people participated. The study was carried out with a single test (July 6 to July 22, 2021). Using logistic regression, adjusted Odds Ratios were calculated according to sex, age, type of vaccine, number of vaccine doses received, complete vaccination schedule, and having had COVID-19.

RESULTS

The vaccines received mostly were Vaxzevria® and Comirnaty®, with 73.3% between both, although 67.2% presented a complete regimen. The results of the OJABIO rapid neutralizing antibody test gave a positive result in 61.4% of the sample. There was a high association between the variables COVID-19 infection, two doses of vaccine, Spikevax® or Comirnaty® vaccine, and eighteen/twenty-nine years old group with a positive result on the OJABIO test. A total of 712 subjects answered the parallel survey (80%) on adverse effects and preferences between the different vaccines against COVID-19.

CONCLUSIONS

The vaccination status against COVID-19 in the university community after six months of the start of national immunization strategies reflects low coverage despite the excellent willingness to get vaccinated. Neutralizing antibodies (NAb) rapid tests can be useful to guide immunization strategies and decide when to administer new booster doses.

Psychological impact of COVID-19 and determinants among Spanish university students

Background

University students are a vulnerable population and faced a significant psychological impact from the COVID-19 pandemic. Therefore, this study aimed to determine the level of fear of COVID-19 among university students and to evaluate the possible relationship between fear of COVID-19 and socio-demographic, health-related determinants, variables related to the COVID-19 and variables related to the psychological impact of the COVID-19 pandemic.

Methods

We conducted a cross-sectional study between December 2020 and December 2021 on a sample of 950 university students from two universities in southern Spain. Participants completed a form that collected socio-demographic, health-related and COVID-related variables, a validated questionnaire related to the psychological impact of the COVID-19 pandemic and the fear of COVID Scale (FCV-19S). Descriptive, inferential, and multivariable linear regression analyzes were conducted.

Results

The mean FCV-19S score was 14.86 ± 5.16 points. The factors identified as predictors of FCV-19S were being female (p < 0.001), holding religious beliefs (p = 0.04), living in towns with over 10,000 inhabitants (p < 0.01), living with someone vulnerable to COVID-19 (p = 0.02), watching TV to keep informed about COVID-19 (p < 0.01), believing in a low probability of surviving if infected with COVID-19 (p < 0.001), having a higher level of death anxiety (p < 0.001) and suffering from insomnia (p < 0.001).

Conclusion

An average fear of COVID-19 score of 14.86 ± 5.16 points has been found among university students in Spain. These findings can aid in identifying specific factors contributing to fear of COVID-19 and in developing coping strategies to alleviate the stress of the pandemic.

Behavioral and Personal Characteristics Associated With Risk of SARS-CoV-2 Infection in a Spanish University Cohort

The aim of this study was to analyze the life habits and personal factors associated with increased severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) risk in a university environment with in-person lectures during the coronavirus disease 2019 (COVID-19) pandemic. To our knowledge, there are no previous longitudinal studies that have analyzed associations of behavioral and personal factors with the risk of SARS-CoV-2 infection on an entire university population. A cohort study was conducted in the 3 campuses of the University of Navarra between August 24, 2020, and May 30, 2021, including 14,496 students and employees; the final sample included 10,959. Descriptive and multivariate-adjusted models were fitted using Cox regression. A total of 1,032 (9.4%) participants were diagnosed with COVID-19 (879 students and 153 employees), almost 50% living with their families. COVID-19 was associated with living in college or residence (hazard ratio (HR) = 1.96, 95% CI: 1.45, 2.64), motor transportation (HR = 1.35, 95% CI: 1.14, 1.61), South American origin (HR = 1.43, 95% CI: 1.20, 1.72), and belonging to Madrid's campus (HR = 3.11, 95% CI: 2.47, 3.92). International students, especially from Latin America, mostly lived in university apartments or shared flats and cohabited with 4-11 people. Living in a big city (Madrid), was a significant risk factor.

The prevalence of SARS-CoV-2 antibodies within the community of a private tertiary university in the Philippines: A serial cross sectional study

The COVID-19 pandemic has caused a public health emergency in all sectors of society, including universities and other academic institutions. This study determined the seroprevalence of SARS-CoV-2 antibodies among administrators, faculty, staff, and students of a private tertiary academic institution in the Philippines over a 7 month period. It employed a serial cross-sectional method using qualitative and quantitative COVID-19 antibody test kits. A total of 1,318 participants were tested, showing 47.80% of the study population yielding IgG antibodies to SARS-CoV-2 virus. A general increase in seroprevalence was observed from June to December 2021, which coincided with the vaccine roll-out of the country. All brands yielded positive antibody formation, with mRNA vaccines having higher levels than other types of vaccines. A decreasing trend in IgG reactivity was found in vaccinated individuals after 1 to 6 months of completion of the 2 doses of the COVID-19 vaccine. Where possible, IgG and T-cell reactivity and/or neutralizing capacity against SAR-CoV-2 need to be monitored regardless of vaccine brand. Together with uptake of COVID-19 vaccines and boosters, other public health interventions such as wearing of masks and regular testing need to be continued for better protection. Effective communication is also needed to inform risks associated with activities across different settings. Investments in long-term measures such as air filtration and ventilation systems, and wastewater surveillance need to be made.

Predictors of SARS-CoV-2 Infection in University Students: A Case-Control Study

Closure of Higher Education Institutions in the early phase of the SARS-CoV-2 pandemic was largely diffused. With their reopening, numerous preventive measures have been enacted, but limited evidence exists on students' behavior that could influence their infection risk. We conducted a case-control study at the Sapienza University of Rome to identify protective and risk factors for SARS-CoV-2 infection. Students attending the campus within 48 h of SARS-CoV-2 infection were considered cases. Controls were students who come in contact with a confirmed case within the campus. Demographic features and activities carried out before positivity or contact were investigated. Multivariable logistic regression models were built to identify factors associated with SARS-CoV-2 infection, estimating adjusted odds ratios (aOR) and 95% confidence intervals (95% CI). The analysis showed an increased risk of SARS-CoV-2 infection for attending the second year or above of university (aOR 17.7, 95% CI 2.21-142.82) and participating in private parties or ceremonies (aOR 15.9, 95% CI 2.30-109.67) while living outside the family (aOR 0.08, 95% CI 0.01-0.54) and attending practical activities or libraries on campus (aOR 0.29, 95% CI 0.08-0.97) reduced the risk. Data strongly suggests that it may be safe to participate in activities organized under strict infection prevention guidelines. Tailored prevention measures might reduce the risk of infection in university students.

COVID-19 in Tunisia (North Africa): Seroprevalence of SARS-CoV-2 in the General Population of the Capital City Tunis

Seroprevalence studies are essential to get an accurate estimate of the actual SARS-CoV-2 diffusion within populations. We report on the findings of the first serosurvey conducted in Tunis prior to the implementation of mass vaccination and analyzed factors associated with seropositivity. A household cross sectional survey was conducted (March–April 2021) in Tunis, spanning the end of the second wave and the beginning of the third wave of COVID-19. SARS-CoV-2 specific immunoglobulin G (IgG) antibodies to the spike (S-RBD) or the nucleocapsid (N) proteins were detected by in-house ELISA tests. The survey included 1676 individuals from 431 households. The mean age and sex ratio were 43.3 ± 20.9 years and 0.6, respectively. The weighted seroprevalence of anti-N and/or anti-S-RBD IgG antibodies was equal to 38.0% (34.6–41.5). In multivariate analysis, age under 10, no tobacco use, previous diagnosis of COVID-19, a history of COVID-19 related symptoms and contact with a COVID-19 case within the household, were independently associated with higher SARS-CoV-2 seroprevalence. More than one third of people living in Tunis obtained antibodies to SARS-CoV-2. Further studies are needed to monitor changes in these figures as Tunisian population is confronted to the subsequent epidemic waves and to guide the vaccine strategy.

Detection of Neutralizing Antibodies against SARS-CoV-2 Post-Vaccination in Health Care Workers of a Large Tertiary Hospital in Spain by Using a Rapid Test LFIC and sVNT-ELISA

The presence of neutralizing antibodies (NAbs) against SARS-CoV-2 represent a surrogate marker of immunologic protection in populations at high risk of infection such as healthcare workers caring for hospitalized patients with COVID-19. As recommended by CDC and the European CDC, the use of rapid diagnostic tests during population-based evaluations offers an opportunity to identify individuals with serologic evidence of natural infection or who have undergone vaccination. We carried out a cross-sectional study to assess the presence of neutralizing antibodies against SARS-CoV-2 among medical providers at an intensive care unit of a large referral hospital in Alicante, Spain. In addition, we tested for the presence of neutralizing antibodies compared to serum of uninfected individuals from a Biobank. We were also interested in evaluating the use of a rapid lateral flow immunochromatography (LFIC) test against a surrogate ELISA viral neutralization test (sVNT). This rapid test demonstrated a specificity of 1.000 95% CI (0.91–1.00) and the sensitivity of 0.987 95% CI (0.93–1.00). The negative predictive value was 95%. After six months, this rapid test demonstrated that those immunized with two doses of BioNTech/Pfizer vaccine, maintained optimal levels of neutralizing antibodies. We concluded that all Health Care Workers develop NAbs and the use of this rapid immunochromatographic test represents a potential tool to be used in population-based studies to detect serological antibody responses to vaccination. Vaccination policies could benefit from this tool to assess additional doses of vaccine or boosters among high-risk populations.

A Cross-Sectional Study of Exposure Factors Associated with Seropositivity for SARS-CoV-2 Antibodies during the Second Epidemic Wave among a Sample of the University of Corsica (France)

This study aimed to estimate the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection within the staff and student populations of the University of Corsica (France) during the second wave of the epidemic. Methods: A cross-sectional survey was conducted from 23 November 2020 to 31 January 2021. The participants underwent blood sampling using a fingerstick procedure and completed an anonymized questionnaire. Sera were tested for the presence of anti-SARS-CoV-2 IgG (ELISA-S) and, if positive, with an in-house virus neutralization test (VNT). Results: A total of 418 persons were included in the study. The overall seroprevalence was 12.8% (95% confidence interval (CI), 9.8–16.6%). A total of 15 (31%) of the 49 individuals who had a positive ELISA-S also had a positive VNT. Seropositivity was associated with living at the city campus during the week and on weekends (OR = 3.74 [1.40–12.00]), using public transportation/carpooling (OR = 2.00 [1.01–4.02]), and being in contact with a person who tested positive for SARS-CoV-2 (OR = 2.32 [1.20–4.40]). The main symptoms associated with seropositivity were “having had an acute respiratory infection” (OR = 3.05 [1.43–6.43]) and “experiencing loss of smell” (OR = 16.4 [5.87–50.7]). Conclusion: These results could be useful for SARS-CoV-2 prevention and control on university campuses.

Factors Affecting Young Adults' Decision Making to Undergo COVID-19 Vaccination: A Patient Preference Study

Young adults are a substantial driver of lagging vaccination against COVID-19 worldwide. We aimed to understand what vaccine or vaccination environment attributes may affect young adults' vaccine inclination. We contacted a convenience sample of 1415 students to recruit a minimum of 150 individuals for a web-based discrete choice experiment. The respondents were asked to choose one of two hypothetical vaccines, defined by six attributes-vaccine efficacy, risk of mild side effects, protection duration, administration route, recommender, and travel time to the vaccination site. Individual preferences were calculated with the Markov chain Monte Carlo hierarchical Bayes estimation. A total of 445 individuals (mean age 24.4 years, 272 (61.1%) women) completed the survey between 22 March and 3 May 2021. Vaccine protection duration (28.3 (95% CI, 27.0-29.6)) and vaccine efficacy in preventing COVID-19 (27.5 (95% CI, 26.3-28.8)) were the most important, followed by the risk of vaccine side effects (17.3 (95% CI, 16.2-18.4)). Individuals reluctant or unsure about vaccination (21.1%) prioritized the potential for mild side effects higher and vaccine efficacy lower than the vaccine-inclined individuals. New vaccination programs that target young adults should emphasize the protection duration, low risk of vaccine side effects, and high efficacy.

Review of Clinical Performance of Serology Based Commercial Diagnostic Assays for Detection of Severe Acute Respiratory Syndrome Coronavirus 2 Antibodies

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, which caused the coronavirus disease 2019 (COVID-19) pandemic as declared by the World Health Organization, has created havoc worldwide. The highly transmissible infection can be contained only by accurate diagnosis, quarantining, and exercising social distancing. Therefore, quick and massive deployment of SARS-CoV-2 testing plays a crucial role in the identification and isolation of infected patients. Reverse transcription-polymerase chain reaction is the gold standard for COVID-19 detection; however, it needs expertise, facilities, and time. Hence, for the ease of population-wide screening, serology-based diagnostic assays were introduced. These can help determine the prevalence of infection, understand the epidemiology of the disease, and assist in suitable public health interventions while being user-friendly and less time consuming. Although serological testing kits in markets soared, their sensitivity and specificity were questioned in reports from different parts of the world. In this article, we have reviewed 40 Food and Drug Administration (FDA) and CE-approved clinically evaluated serological kits (8 enzyme-linked immunosorbent assay [ELISA] kits, 10 chemiluminescent immunoassay [CLIA] kits, and 22 lateral flow immunoassay [LFIA] kits) for their sensitivity and specificity and discussed the apparent reasons behind their performance. We observed appreciable sensitivity in the kits detecting total antibodies compared to the kits targeting single isotype antibodies. Tests that determined antibodies against nucleocapsid protein were found to be more sensitive and those detecting antibodies against spike protein were found to have greater specificity. This study was conducted to help the decision-making while acquiring antibody kits and concurrently to be mindful of their shortcomings.

Seroprevalence of antibodies against SARS-Cov-2 in the high impacted sub-district in Jakarta, Indonesia

Background

Understanding the actual prevalence of COVID-19 transmission in the community is vital for strategic responses to the pandemic. This study aims to estimate the actual infection of COVID-19 through a seroprevalence survey and to predict infection fatality rate (IFR) in Tanjung Priok, the hardest-hit sub-district by the COVID-19 in Jakarta, Indonesia.

Methods

We conducted a venous blood sampling (phlebotomy) to 3,196 individuals in Tanjung Priok between Nov 23, 2020, and Feb 19, 2021 to detect their antibodies against SARS-CoV-2. Using an enumerator-administered questionnaire, we collected data on the respondents’ demographic characteristics, COVID-19 test history, COVID-19 symptoms in the last 14 days, comorbidities, and protective behaviours during the last month. We employed descriptive analysis to estimate the seroprevalence and IFR.

Findings

The prevalence of Antibody against SARS-CoV-2 was 28.52% (95% CI 25.44–31.81%), with the result being higher in females than males (OR 1.20; 95% CI 1.02–1.42). By the end of the data collection (February 9, 2021), the cumulative cases of COVID-19 in Tanjung Priok were reported to be experienced by 9,861 people (2.4%). Those aged 45–65 were more likely to be seropositive than 15–19 years old (OR 1.42; 95% CI 1.05–1.92). Nearly one third (31%) of the subjects who developed at least one COVID-19 symptom in the last 14 days of the data collection were seropositive. The estimated IFR was 0.08% (95% CI 0.07–0.09), with a higher figure recorded in males (0.09; 95% CI 0.08–0.10) than females (0.07; 95% CI 0.06–0.08), and oldest age group (45–65) (0.21; 95% CI 0.18–0.23) than other younger groups.

Conclusion

An under-reporting issue was found between the estimated COVID-19 seroprevalence and the reported cumulative cases in Tanjung Priok. More efforts are required to amplify epidemiological surveillance by the provincial and local governments.

Seroprevalence of Anti-SARS-CoV-2 Antibodies among Municipal Staff in the Municipality of Prishtina

BACKGROUND

Some studies have assessed the seroprevalence of anti-SARS-CoV-2 antibodies in different populations. Very few studies have explored seroprevalence in municipal workers, an important and potentially high-risk population. This study aims to determine the prevalence of anti-SARS-CoV-2 antibodies in municipal workers, with the additional examination of the association of prevalence with various demographic, health-related, and epidemiological factors.

METHODS

We surveyed and tested for seroprevalence 418 public servants from the municipality of Prishtina, the capital of Kosovo. The primary prespecified outcome was the seroprevalence of anti-SARS-CoV-2 antibodies, IgG, and IgM. Additional outcomes were crude and adjusted odds ratios of seroprevalence by different factors.

RESULTS

21.1% of municipal workers tested positive for either IgM or IgG. Of these, 9.6% were positive for IgM and 19.4% for IgG. Data showed high levels of adherence to protective measures, e.g., social distancing in the office, but calculation of ORs did not show a significant difference between those reporting adherence to such measures and those reporting nonadherence. Of other examined factors, significantly lower odds were observed for smokers (0.52, 95% CI 0.28, 0.97), while municipal workers with infected family members had elevated odds of seropositivity according to both crude (2.19, 95% CI 1.34, 3.59) and adjusted (2.00, 95% CI 1.17, 3.41) ORs.

CONCLUSIONS

Most answers from public servants demonstrated compliance to social-distancing policies in the workplace, but analysis of crude and adjusted odds ratios did not suggest a significant effect between municipal workers who followed these guidelines and those who did not. Results from this study help Kosovo policy makers in understanding the level of prevalence of COVID-19 in municipal workers and the effect of different factors on such prevalence. Results from the study could inform future decisions on the design and application of protective measures for municipal workers. Our findings should encourage further research to assess the extent of the spread of COVID-19 to other essential workers in Kosovo, including retail workers.

High Seroprevalence Against SARS-CoV-2 Among Faculty of Medicine and Health Sciences Personnel and Students of the University of Alcalá, Spain: Contributing Factors

Purpose

Seroprevalence against SARS-CoV-2 within university systems is poorly studied, making evidence-based discussions of educational system reopening difficult. Moreover, few studies evaluate how antibodies against SARS-CoV-2 are maintained over time. We assessed serological response against the SARS-CoV-2 virus among our university students and staff.

Patients and Methods

In this prospective cohort study, seroprevalence was determined in 705 randomly selected volunteers, members of the Faculty of Medicine and Health Sciences of the University of Alcalá, using a chemiluminescent Siemens' SARS-CoV-2 immunoassay for total antibodies. Positive samples were tested for IgG and IgM/IgA using VIRCLIA^® MONOTEST (Vircell). A first analysis took place during June 2020, and in those testing positive, a determination of secondary outcomes was performed in November 2020.

Results

A total of 130 subjects showed anti-SARS-CoV-2 antibodies (18.5%, 95% CI, 15.8-21.5%). Of these, IgM/IgA was positive in 27 and indeterminate in 19; IgG was positive in 118, indeterminate in 1. After 23 weeks, among 102 volunteers remeasured, IgG became undetectable in 6. Presence of antibodies was associated, in multivariable logistic regression, with exposure to infected patients (31.3%) [OR 1.84, 95% CI, 1.14-2.96; P = 0.012], presence of COVID-19 symptoms (52.4%) [OR 6.88, 95% CI, 4.28-11.06; P < 0.001], and confirmed earlier infection (82.9%) [OR 11.87, 95% CI, 4.26-33.07; P < 0.001].

Conclusions

The faculty of medicine and health sciences personnel and students of our university showed a high infection rate for SARS-CoV-2 during 2020 associated with providing clinical care to infected patients. This emphasizes the importance of the performance of continuous surveillance methods of the most exposed health personnel, including health science students.

Seroprevalence of SARS-CoV-2 Antibodies and Factors Associated with Seropositivity at the University of Salamanca: The DIANCUSAL Study

BACKGROUND

Systematic screening for antibodies against SARS-CoV-2 is a crucial tool for surveillance of the COVID-19 pandemic. The University of Salamanca (USAL) in Spain designed a project called "DIANCUSAL" (Diagnosis of New Coronavirus, COVID-19, in University of Salamanca) to measure antibodies against SARS-CoV-2 among its ~34,000 students and academic staff, as the influence of the university community in the spread of the SARS-CoV-2 pandemic in the city of Salamanca and neighboring towns hosting USAL campuses could be substantial.

OBJECTIVE

The aim of this study was to estimate the prevalence of SARS-CoV-2 antibodies among USAL students, professors and staff and to evaluate the demographic, academic, clinical and lifestyle and behavioral factors related to seropositivity.

METHODOLOGY

The DIANCUSAL study is an ongoing university population-based cross-sectional study, with the work described herein conducted from July-October 2020. All USAL students, professors and staff were invited to complete an anonymized questionnaire. Seroprevalence of anti-SARS-CoV-2 antibodies was detected and quantified by using chemiluminescent assays for IgG and IgM.

PRINCIPAL FINDINGS

A total of 8197 (24.71%) participants were included. The mean age was 31.4 (14.5 SD) years, and 66.0% of the participants were female. The seroprevalence was 8.25% overall and was highest for students from the education campus (12.5%) and professors from the biomedical campus (12.6%), with significant differences among faculties (p = 0.006). Based on the questionnaire, loss of smell and fever were the symptoms most strongly associated with seropositivity, and 22.6% of seropositive participants were asymptomatic. Social distancing was the most effective hygiene measure (p = 0.0007). There were significant differences in seroprevalence between participants with and without household exposure to SARS-CoV-2 (p = 0.0000), but not between students who lived in private homes and those who lived in dormitories. IgG antibodies decreased over time in the participants with confirmed self-reported COVID-19 diagnoses.

CONCLUSIONS

The analysis revealed an overall 8.25% seroprevalence at the end of October 2020, with a higher seroprevalence in students than in staff. Thus, there is no need for tailored measures for the USAL community as the official average seroprevalence in the area was similar (7.8% at 22 June and 12.4 at 15 November of 2020). Instead, USAL members should comply with public health measures.

Seroprevalence of SARS-CoV-2 Antibodies in Adults and Healthcare Workers in Southern Italy

BACKGROUND

This study was carried out to estimate the seroprevalence of SARS-CoV-2 antibodies in a Southern Italian population.

METHODS

The study was performed among students and workers of the University of Campania "Luigi Vanvitelli" and the relative Teaching Hospital. Participants were invited to undergo a blood sampling, an interview or to complete a self-administered questionnaire.

RESULTS

A total of 140 participants (5.8%) tested positive for SARS-CoV-2 antibodies. Positive SARS-CoV-2 test results increased significantly during the months of testing, and those who had had at least one symptom among fever, cough, dyspnea, loss of taste or smell and who had had contact with a family member/cohabitant with confirmed COVID-19 were more likely to test positive. Faculty members were less likely to have a positive test result compared to the healthcare workers (HCWs). Among HCWs, physicians showed the lowest rate of seroconversion (5.2%) compared to nurses (8.9%) and other categories (10%). Nurses and other HCWs compared to the physicians, those who had had at least one symptom among fever, cough, dyspnea, loss of taste or smell, and who had had contact with a family member/cohabitant with confirmed COVID-19 were more likely to test positive.

CONCLUSIONS

The results have demonstrated that SARS-CoV-2 infection is rapidly spreading even in Southern Italy and confirm the substantial role of seroprevalence studies for the assessment of SARS-CoV-2 infection circulation and potential for further spreading.

The Effectiveness of the Blended Learning in Conservative Dentistry with Endodontics on the Basis of the Survey among 4th-Year Students during the COVID-19 Pandemic

The COVID-19 pandemic has undoubtedly affected education at all levels, including medical and dental education. Our study aimed to assess the effectiveness of the blended learning in conservative dentistry with endodontics. The students had theoretical classes in a remote form (using the e-learning portal and Teams communicator) and practical classes with the participation of patients in the appropriate sanitary regime. The author's survey was conducted among fourth-year dental students. The online questionnaire consisted of 5 parts: self-evaluation, evaluation of theoretical e-learning classes, evaluation of practical clinical classes, evaluation of safety, and evaluation of performed blended learning. The majority of respondents declared that their learning effectiveness increased during the pandemic. Most surveyed students preferred remote learning in asynchronous form (e-learning portals) to synchronous form (virtual meetings in real-time). All respondents described the provided personal protective equipment as sufficient or even as excessive. Our students were very satisfied with the proposed blended-learning model and would like to continue it even after the pandemic has ended. Among the advantages, they particularly mentioned the increase in efficiency and the individualised pace of learning, while the disadvantage was the limitation of social contacts. The appropriate use of modern technology can effectively revolutionise dental education.