ABSTRACT
In the Czech Republic, the first wave of the COVID-19 epidemic, caused by the SARS-CoV-2 virus, occurred in the spring of 2020, peaking at the end of March. From March 1st to May 31st, a total of 9,230 people tested positive by PCR were detected. We assessed the prevalence of COVID-19 infections in employees of the National Institute of Public Health at the end of the first wave by detecting specific antibodies against SARS-CoV-2. Voluntary testing for the presence of IgA and IgG antibodies was performed by ELISA tests using Euroimmun SARS-CoV-2 IgA and Euroimmun SARS-CoV-2 IgG semi-quantitative commercial assays. The participants answered a questionnaire regarding symptoms of an acute respiratory infection in the last quarter and known contact with COVID-19 infection. A total of 78 out of 270 persons (29%) experienced symptoms of acute respiratory infection, 7 (2.6%) lost the olfactory sense or taste and 15 (5.6%) were in contact with an infected person. The first sampling was performed between April 6th and May 22nd, 2020. A total of 270 employees were tested, of which 224 (83%) were women. The IgA and IgG antibodies SARS-CoV-2 were positive or borderline in 31 subjects. The second sample was taken from 30 of them and the third sample was from taken two persons several weeks apart. Based on the dynamics of the antibodies, 10 (3.7% of the whole group) were evaluated as seropositive, in whom we indirectly infer a past SARS-CoV-2 infection. A total of 246 people had negative serology (of which 239 based on the first sample and 7 based on the second one). In 14 people it was not possible to determine whether an infection occurred, i.e. the result was evaluated as inconclusive. The positive association of persistent seroconversion in the symptomatic subjects compared to the asymptomatic ones was statistically insignificant with a relative risk of 1.61 (95% CI: 0.47–5.54), p = 0.449. © 2021, Czech Medical Association J.E. Purkyne. All rights reserved.
ABSTRACT
PURPOSE: To assess the presence of anti-SARS-CoV-2 IgA in the conjunctival secretions of confirmed COVID-19 patients by nasopharyngeal swabs and correlate its presence with the severity of the disease, patient's age, sex and ocular symptoms. METHODS: This study included 44 positive COVID-19 patients confirmed with nasopharyngeal swabs during the period 17-28 February 2021 at Sohag Tropical Medicine Hospital. Tears and conjunctival secretions were examined for the presence of anti-SARS-CoV-2 IgA. RESULTS: While non-reactive results are strongly correlated to low titre and vice versa, severity showed significant correlation with neither IgA reactivity nor titre. Meanwhile, IgA reactivity did not show significant correlation with either age or sex. The reactivity and IgA titre are correlated with ocular symptoms. CONCLUSION: The anti-SARS-CoV-2 IgA could be found in ocular secretions in SARS-CoV-2 patients. There is no correlation with age or sex or severity of the disease; however, they are correlated with ocular symptoms.
ABSTRACT
(1) Background: Healthcare workers (HCWs) are prone to intensified exposure to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in the ongoing pandemic. We prospectively analyzed the prevalence of antibodies against SARS-CoV-2 in HCWs at baseline and follow up with regard to clinical signs and symptoms in two university hospitals in Brandenburg, Germany. (2) Methods: Screening for anti-SARS-CoV-2 IgA and IgG antibodies was offered to HCWs at baseline and follow up two months thereafter in two hospitals of Brandenburg Medical School during the first wave of the COVID-19 pandemic in Germany in an ongoing observational cohort study. Medical history and signs and symptoms were recorded by questionnaires and analyzed. (3) Results: Baseline seroprevalence of anti-SARS-CoV-2 IgA was 11.7% and increased to 15% at follow up, whereas IgG seropositivity was 2.1% at baseline and 2.2% at follow up. The rate of asymptomatic seropositive cases was 39.5%. Symptoms were not associated with general seropositivity for anti-SARS-CoV-2; however, class switch from IgA to IgG was associated with increased symptom burden. (4) Conclusions: The seroprevalence of antibodies against SARS-CoV-2 was low in HCWs but higher compared to population data and increased over time. Screening for antibodies detected a significant proportion of seropositive participants cases without symptoms.