Measurement of anti SARS-CoV-2 RBD IgG in saliva: validation of a highly sensitive assay and effects of the sampling collection method and correction by protein.

OBJECTIVES: To develop and evaluate a new highly sensitive assay to detect IgG anti-SARS-CoV-2 RBD in saliva samples. METHODS: A two-step sandwich type immunoassay based on the amplified luminescent proximity homogeneous technology was developed and an analytical validation was performed. As a part of this validation, the influence of factors, such as different sampling conditions (stimulated saliva and passive drool) and the correction of values by total protein content, in the ability of saliva to detect increases in antibodies after an immune stimulus and be an alternative to serum, was evaluated. For this purpose, paired samples of saliva and serum at different times after vaccination were used. RESULTS: Saliva concentrations were lower than serum, but both fluids showed similar kinetics, with higher correlations when saliva was obtained by passive flow and the results were not corrected by protein. CONCLUSIONS: The developed method showed a good analytical performance and can properly measure antibody concentrations in saliva of vaccinated individuals. However, saliva could have a lower sensitivity compared to serum at initial stages of the immune response and also when the antibody response decreased after a stimulus.

El impacto de la pandemia de COVID-19 sobre la salud. Informe SESPAS 2022 Health impact of COVID pandemic. SESPAS Report 2022

Objetivo Presentar, a los 22 meses de que la Organización Mundial de la Salud declarara como pandemia la infección global por SARS-CoV-2 el 11 de marzo de 2020, el impacto hasta el momento de la pandemia en términos de salud física y mental. Método Se han revisado resultados procedentes de metaanálisis y revisiones sistemáticas, citándose para algún aspecto específico de interés artículos individuales. La información nacional procede de la Red Nacional de Vigilancia Epidemiológica (RENAVE). Resultados Hasta finales de octubre se habían producido más de 250 millones de infecciones y 5 millones de muertes. En España se han notificado 4,7 millones de infecciones, aunque la cifra real es superior a los 7 millones. Se ha reducido la esperanza de vida, con efectos especialmente dramáticos en grupos de población con comorbilidad y de edad avanzada. Se constata un empeoramiento de la salud mental general. Es previsible que algunos colectivos, como los/las profesionales sanitarios/as, en su mayoría mujeres, y trabajadores/as de primera línea, tengan un mayor riesgo de desarrollar patologías de salud mental en el futuro. La pandemia y las medidas de control han tenido otras consecuencias indeseables, como la disminución de la actividad asistencial, el aumento del sedentarismo y el aumento de la violencia de género. Conclusiones Son necesarios estudios longitudinales para determinar la magnitud de las consecuencias de la propia infección y de las medidas de control y las actuaciones necesarias.

[Health impact of COVID pandemic. SESPAS Report 2022]. / El impacto de la pandemia de COVID-19 sobre la salud. Informe SESPAS 2022.

OBJECTIVE: The World Health Organization declared the global SARS-CoV-2 infection a pandemic on March 11, 2020. The objective of this paper is to present its impact in terms of physical and mental health 22 months later. METHOD: We have reviewed results from published meta-analysis and systematic reviews, and some individual articles on specific aspects of special interest. National information on infection comes for the Red Nacional de Vigilancia Epidemiológica (RENAVE). RESULTS: Up to the end of October, more than 250 million infections and 5 million deaths had been reported globally. In Spain, 4.7 million infections have been documented although the real figure might be above 7 million. The pandemic has reduced life expectancy, and its effects have been especially dramatic in people with comorbidities and the elderly. There is a worsening of mental health in the general population. It is foreseeable that some groups, such as health professionals, mostly women, and front-line workers, may have a greater risk of developing mental health pathologies. The pandemic and the control measures have had other undesirable consequences such as a decrease in healthcare utilization, an increase in sedentary lifestyle or an increase in gender violence. In addition to its immediate effect on morbidity and mortality, the control measures have damaged the overall health status of the global population. CONCLUSIONS: Longitudinal studies are necessary to determine the mid and long consequences of the pandemic and the control measures, and to identify and evaluate effective health interventions.

Saliva changes in composition associated to COVID-19: a preliminary study.

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV 2), is usually associated with a wide variety of clinical presentations from asymptomatic to severe cases. The use of saliva as a diagnostic and monitoring fluid has gained importance since it can be used to investigate the immune response and to direct quantification of antibodies against COVID-19. Additionally, the use of proteomics in saliva has allowed to increase  our understanding of the underlying pathophysiology of diseases, bringing new perspectives on diagnostics, monitoring, and treatment. In this work, we compared the salivary proteome of 10 patients with COVID-19, (five patients with mild and five patients with severe COVID-19) and ten control healthy patients. Through the application of proteomics, we have identified 30 proteins whose abundance levels differed between the COVID-19 groups and the control group. Two of these proteins (TGM3 and carbonic anhydrase-CA6) were validated by the measurement of gGT and TEA respectively, in 98 additional saliva samples separated into two groups: (1) COVID-19 group, integrated by 66 patients who tested positive for COVID-19 (2) control group, composed of 32 healthy individuals who did not show any sign of disease for at least four weeks and were negative for COVID-19 in RT-PCR. In the proteomic study there were observed upregulations in CAZA1, ACTN4, and ANXA4, which are proteins related to the protective response against the virus disturbance, and the upregulation of TGM3, that is correlated to the oxidative damage in pulmonary tissue. We also showed the downregulation in cystatins and CA6 that can be involved in the sensory response to stimulus and possibly related to the presence of anosmia and dysgeusia during the COVID-19. Additionally, the presence of FGB in patients with severe COVID-19 but not in mild COVID-19 patients could indicate a higher viral aggregation and activation in these cases. In conclusion, the salivary proteome in patients with COVID-19 showed changes in proteins related to the protective response to viral infection, and the altered sensory taste perception that occur during the disease. Moreover, gGT and TEA could be potential biomarkers of respiratory complications that can occurs during COVID 19 although further larger studies should be made to corroborate this.

Salivary Ferritin Changes in Patients with COVID-19.

High ferritin serum levels can be found in patients with macrophage activation syndrome, and increased serum ferritin due to cytokine storm have been reported in severe COVID-19 patients. Saliva is being increasingly used in COVID-19 tests as a diagnostic sample for virus detection and quantification. This study aimed to evaluate the possible changes in ferritin in saliva in COVID-19 patients. In addition, the effects of different inactivation SARS-CoV-2 treatments in ferritin measurements in saliva, the correlation between ferritin in saliva and serum, and the possible effects of correction of ferritin values by total protein were assessed. Ferritin was measured in saliva from healthy (n = 30) and COVID-19 (n = 65) patients with severe, (n = 18) or mild (n = 47) disease, depending on the need for nasal flow oxygen or assisted respiration. Ferritin was also measured in paired serum and saliva samples (n = 32) from healthy and COVID-19 patients. The evaluated inactivation protocols did not affect the assay's results except the addition of 0.5% SDS. Significantly higher ferritin was found in the saliva of COVID-19 patients (median; 25-75th percentile) (27.75; 9.77-52.2 µg/L), compared with healthy controls (4.21; 2.6-8.08 µg/L). Individuals with severe COVID-19 showed higher ferritin values in saliva (48.7; 18.7-53.9) than mild ones (15.5; 5.28-41.3 µg/L). Significant correlation (r = 0.425; p < 0.001) was found between serum and saliva in ferritin. Ferritin levels were higher in COVID-19 patients in serum and saliva, and the highest values were found in those patients presenting severe symptomatology. In conclusion, ferritin in saliva has the potential to be a biomarker to evaluate severity in patients with COVID-19.

Role of access to personal protective equipment, treatment prioritization decisions, and changes in job functions on health workers' mental health outcomes during the initial outbreak of the COVID-19 pandemic.

BACKGROUND: During the initial COVID-19 outbreak, organizational changes were required to ensure adequate staffing in healthcare facilities. The extent to which organizational changes impacted the mental wellbeing of healthcare workers (HCWs) remains unexplored. Here we analyzed the association between three work-related stressors (reported access to protective equipment, change in job functions, and patient prioritization decision-making) and mental health outcomes (depression symptoms, psychological distress, suicidal thoughts, and fear of infection) in a large sample of Spanish HCWs during the initial COVID-19 outbreak. METHODS: We conducted a cross-sectional study including HCWs from three regions of Spain between April 24th and June 22nd, 2020. An online survey measured sociodemographic characteristics, work-related stressors, fear of infection, and mental health outcomes (depression [PHQ-9], psychological distress [GHQ-12], death wishes [C-SSRS]). We conducted mixed-effects regression models to adjust all associations for relevant individual- and region-level sources of confounding. RESULTS: We recruited 2,370 HCWs. Twenty-seven percent screened positive for depression and 74% for psychological distress. Seven percent reported death wishes. Respondents were more afraid of infecting their loved ones than of getting infected themselves. All work-related stressors were associated with depression symptoms and psychological distress in adjusted models. LIMITATIONS: Non-probabilistic sampling, potential reverse causation. CONCLUSIONS: Modifiable work-related stressors are associated with worse mental health among HCWs. Our results suggest that workplace prevention strategies for HCWs should provide sufficient protective equipment, minimize changes in job functions, favor the implementation of criteria for patient triage and on-call bioethics committees, and facilitate access to stepped-care, evidence-based mental health treatment.

Evaluation of sample treatments in a safe and straightforward procedure for the detection of SARS-CoV-2 in saliva.

OBJECTIVES: To evaluate four sample treatments in a safe and straightforward procedure to detect SARS-CoV-2 in saliva. METHODS: Four sample treatments were evaluated in a 3-step procedure to detect SARS-CoV-2 in saliva: 1) heating at 95 °C for 5 min for sample inactivation; 2) sample treatment; 3) analysis by reverse-transcription loop-mediated isothermal amplification (LAMP). Saliva samples used were from infected individuals or were spiked with known quantities of viral particles. RESULTS: Three treatments had a limit of detection (LOD) of 500.000 viral particles per ml of saliva and could be used to detect individuals with potential to transmit the disease. The treatment of phosphate buffer, dithiothreitol, ethylenediaminetetraacetic acid and proteinase K, with an additional 95 °C heating step, yielded a lower LOD of 95; its sensitivity ranged from 100% in patients with nasopharyngeal swab reverse-transcriptase polymerase chain reaction cycle threshold values <20 to 47.8% for values >30. CONCLUSIONS: This report highlights the importance of an adequate sample treatment for saliva to detect SARS-CoV-2 and describes a flexible procedure that can be adapted to point-of-care. Although its sensitivity when LAMP is used is lower than reverse-transcriptase polymerase chain reaction, this procedure can contribute to COVID-19 control by detecting individuals able to transmit the disease.

Analytical validation of an automated assay for the measurement of adenosine deaminase (ADA) and its isoenzymes in saliva and a pilot evaluation of their changes in patients with SARS-CoV-2 infection.

OBJECTIVES: The aim of the present study was to validate a commercially available automated assay for the measurement of total adenosine deaminase (tADA) and its isoenzymes (ADA1 and ADA2) in saliva in a fast and accurate way, and evaluate the possible changes of these analytes in individuals with SARS-CoV-2 infection. METHODS: The validation, in addition to the evaluation of precision and accuracy, included the analysis of the effects of the main procedures that are currently being used for SARS-CoV-2 inactivation in saliva and a pilot study to evaluate the possible changes in salivary tADA and isoenzymes in individuals infected with SARS-CoV-2. RESULTS: The automated assay proved to be accurate and precise, with intra- and inter-assay coefficients of variation below 8.2%, linearity under dilution linear regression with R2 close to 1, and recovery percentage between 80 and 120% in all cases. This assay was affected when the sample is treated with heat or SDS for virus inactivation but tolerated Triton X-100 and NP-40. Individuals with SARS-CoV-2 infection (n=71) and who recovered from infection (n=11) had higher mean values of activity of tADA and its isoenzymes than healthy individuals (n=35). CONCLUSIONS: tADA and its isoenzymes ADA1 and ADA2 can be measured accurately and precisely in saliva samples in a rapid, economical, and reproducible way and can be analyzed after chemical inactivation with Triton X-100 and NP-40. Besides, the changes observed in tADA and isoenzymes in individuals with COVID-19 open the possibility of their potential use as non-invasive biomarkers in this disease.