ABSTRACT
BackgroundSerology testing is explored for epidemiological research and to inform individuals after suspected infection. During the COVID-19 pandemic, frontline healthcare professionals (HCP) may be at particular risk for infection. No longitudinal data on functional seroconversion in HCP in regions with low COVID-19 prevalence and low pre-test probability exist. MethodsIn a large German university hospital, we performed weekly questionnaire assessments and anti-SARS-CoV-2 IgG measurements with various commercial tests, a novel surrogate virus neutralization test, and a neutralization assay using live SARS-CoV-2. ResultsFrom baseline to week six, n=1,080 screening measurements for anti-SARS CoV-2 (S1) IgG from n=217 frontline HCP (65% female) were performed. Overall, 75.6% of HCP reported at least one symptom of respiratory infection. Self-perceived infection probability declined over time (from mean 20.1% at baseline to 12{middle dot}4 % in week six, p<0.001). In sera of convalescent PCR-confirmed COVID-19 patients, we measured high anti-SARS-CoV-2 IgG levels, obtained highly concordant results from ELISAs using e.g. the S1 spike protein domain and the nucleocapsid protein (NCP) as targets, and confirmed antiviral neutralization. However, in HCP the cumulative incidence for anti-SARS-CoV-2 (S1) IgG was 1.86% for positive and 0.93% for equivocal positive results over the six week study period. Except for one HCP, none of the eight initial positive results were confirmed by alternative serology tests or showed in vitro neutralization against live SARS CoV-2. The only true seroconversion occurred without symptoms and mounted strong functional humoral immunity. Thus, the confirmed cumulative incidence for neutralizing anti-SARS-CoV-2 IgG was 0.47%. ConclusionWhen assessing anti-SARS-CoV-2 immune status in individuals with low pre-test probability, we suggest confirming positive results from single measurements by alternative serology tests or functional assays. Our data highlight the need for a methodical serology screening approach in regions with low SARS-CoV-2 infection rates.
Subject(s)
COVID-19ABSTRACT
Background: The COVID-19 pandemic has disrupted healthcare systems worldwide. Besides the direct impact of the virus on morbidity and mortality of patients, the effect of lockdown strategies on health and healthcare utilization become more and more apparent. Little is known on the effect of the pandemic on pediatric healthcare utilization. We examined the impact of the pandemic on pediatric emergency healthcare. Methods: : We conducted a monocentric, retrospective analysis of n=5.424 pediatric emergency visits between January 1 st and April 19 th of 2019 and 2020, and compared healthcare utilization in the month post lockdown 2020 to the same period in 2019. Results: : In the four weeks after lockdown in Germany began, we observed a massive drop of 63.8% in pediatric emergency healthcare utilization (mean daily visits 26.8 ±SEM 1.5 in 2019 vs. 9.7 ±SEM 1 in 2020, p<0.005). This drop in cases occurred for both communicable and non-communicable diseases. A larger proportion of patients under one year old (daily mean of 16.6% ±SEM 1.4 in 2019 vs 23.1% ±SEM 1.7, p<0.01 in 2020) and of cases requiring hospitalisation (mean of 13.9% ±SEM 1.6 in 2019 vs. 26.6% ±SEM 3.3 in 2020, p<0.001) occurred during the pandemic. During the analysed time periods, few intensive care admissions and no fatalities occurred. Conclusion: Our data illustrate a significant decrease in pediatric emergency room visits during the COVID-19 pandemic. Public outreach is needed to encourage parents to seek medical attention for pediatric emergencies in spite of the pandemic.