ABSTRACT
OBJECTIVE: To evaluate dynamics of antibody levels following exposure to SARS-CoV-2 during 12 months in Dutch non-vaccinated hairdressers and hospitality staff. METHODS: In this prospective cohort study, blood samples were collected every three months for one year, and analyzed using a qualitative total antibody ELISA and a quantitative IgG antibody ELISA. Participants filled out questionnaires, providing information on demographics, health and work. Differences in antibody levels were evaluated using Mann-Whitney U and Wilcoxon Signed Rank tests. Beta coefficients (B) and 95% confidence intervals (95%CI) were calculated using linear regression. RESULTS: Ninety-five of 497 participants (19.1%) had ≥1 seropositive measurement before their last visit using the qualitative ELISA. Only 2.1% (2/95) seroreverted during follow-up. Of the 95 participants, 82 (86.3%) tested IgG seropositive in the quantitative ELISA too. IgG antibody levels significantly decreased in the first months (p<0.01), but remained detectable up to 12 months in all participants. Higher age (B, 10-years increment: 24.6, 95%CI: 5.7-43.5) and higher BMI (B, 5kg/m² increment: 40.0, 95%CI: 2.9-77.2) were significantly associated with a higher peak of antibody levels. CONCLUSIONS: In this cohort, SARS-CoV-2 antibodies persisted for up to one year after initial seropositivity, suggesting long-term natural immunity.
ABSTRACT
COVID-19 has made a global impact since early 2020, requiring characterization of the SARS-CoV-2 virus, including transmission risk. The COco-study aims to evaluate the risk for COVID-19 infections in two non-medical contact-intensive professions. COco is a prospective cohort study evaluating SARS-CoV-2 antibodies in hairdressers and hospitality personnel in the province of North-Brabant in the Netherlands, using a total antibody enzyme-linked immunosorbent assay. Baseline data from June/July 2020 were analyzed. Participants filled out a questionnaire, providing information on demographics, health, work situation, and risk factors for COVID-19. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using logistic regression. In June/July 2020, 497 participants were enrolled: 236 hairdressers, 259 hospitality employees, and two participants worked in both industries. Hospitality staff was more frequently seropositive than hairdressers (14.2% versus 8.0%, respectively; OR 1.9, 95% CI 1.1-3.4). Furthermore, a high education level (OR 3.0, 95% CI: 1.7-5.6) and increased alcohol use (OR, 7 glasses per week increment: 1.3, 95% CI: 1.1-1.5) were associated with seropositivity. Of the 56 seropositive participants, 18 (32%) had not experienced any COVID-19 symptoms. The symptoms anosmia/ageusia differed most evidently between seropositive and seronegative participants (53.6% versus 5.7%, respectively; P < 0.001 (chi-squared test)). In conclusion, four months after the first identified COVID-19 patient in the Netherlands, employees in the hospitality industry had significantly more frequently detectable SARS-CoV-2 antibodies than hairdressers.
ABSTRACT
BACKGROUND: It is expected that GPs are increasingly confronted with a large group of patients with symptoms persisting three weeks after initial symptoms of a mild (managed in the outpatient setting) COVID-19 infection. Currently, research on these persistent symptoms mainly focuses on patients with severe infections (managed in an inpatient setting) whereas patients with mild disease are rarely studied. OBJECTIVE: The main objective of this systematic review was to create an overview of the nature and frequency of persistent symptoms experienced by patients after mild COVID-19 infection. METHODS: Systematic literature searches were performed in Pubmed, Embase and PsychINFO on 2 February 2021. Quantitative studies, qualitative studies, clinical lessons and case reports were considered eligible designs. RESULTS: In total, nine articles were included in this literature review. The frequency of persistent symptoms in patients after mild COVID-19 infection ranged between 10% and 35%. Symptoms persisting after a mild COVID-19 infection can be distinguished into physical, mental and social symptoms. Fatigue was the most frequently described persistent symptom. Other frequently occurring persistent symptoms were dyspnoea, cough, chest pain, headache, decreased mental and cognitive status and olfactory dysfunction. In addition, it was found that persisting symptoms after a mild COVID-19 infection can have major consequences for work and daily functioning. CONCLUSION: There is already some evidence that symptoms of mild COVID-19 persist after 3 weeks in a third of patients. However, there is a lack of data about symptoms persisting after 3 months (long-COVID). More research is needed to help GPs in managing long-COVID.