Molecular epidemiology of the SARS-CoV-2 variant Omicron BA.2 sub-lineage in Denmark, 29 November 2021 to 2 January 2022.

Following emergence of the SARS-CoV-2 variant Omicron in November 2021, the dominant BA.1 sub-lineage was replaced by the BA.2 sub-lineage in Denmark. We analysed the first 2,623 BA.2 cases from 29 November 2021 to 2 January 2022. No epidemiological or clinical differences were found between individuals infected with BA.1 versus BA.2. Phylogenetic analyses showed a geographic east-to-west transmission of BA.2 from the Capital Region with clusters expanding after the Christmas holidays. Mutational analysis shows distinct differences between BA.1 and BA.2.

Lung Function Decline in Relation to COVID-19 in the General Population: A Matched Cohort Study With Prepandemic Assessment of Lung Function.

BACKGROUND: To quantify the potential decline in dynamic lung volumes following coronavirus disease 2019 (COVID-19) in the general population. METHODS: A prospective matched cohort study of adult Copenhagen General Population Study (CGPS) participants with a prepandemic spirometry available. CGPS individuals with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) test performed repeat spirometry, a questionnaire regarding respiratory symptoms, and diffusing capacity test for carbon monoxide. A matched uninfected CGPS control sample was used, and simple regression and linear mixed effect models were computed to study lung function decline. RESULTS: A total of 606 individuals were included; 92/107 (85.9%) with positive SARS-CoV-2 PCR test experienced coronavirus disease 2019 (COVID-19) symptoms and 12 (11.2%) were hospitalized. Spirometry was performed at median 5.6 months (interquartile range, 3.9-12.8) after positive SARS-CoV-2 PCR test. COVID-19 was associated with adjusted 7.3 mL (95% confidence interval [CI], .3-14.3) and 22.6 mL (95% CI, 13.1-32.0) steeper decline in annual forced expiratory volume in first second (FEV1) and FVC or total 113.8 and 301.3 mL lower FEV1 and FVC from baseline to follow-up. Results were robust in analyses restricted to individuals not requiring hospitalization. CONCLUSIONS: COVID-19-related declines of dynamic lung volume in the general population not requiring hospitalization were small but measurable.

A prospective cohort study of confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy evaluating SARS-CoV-2 antibodies in maternal and umbilical cord blood and SARS-CoV-2 in vaginal swabs.

INTRODUCTION: Evidence about the consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pregnancy is rapidly increasing; however, data on antibody response and risk of transmission during pregnancy and delivery are still limited. The aim of this study was to evaluate if SARS-CoV-2 is detectable in vaginal swabs and whether antibodies against SARS-CoV-2 are present in maternal and umbilical cord blood of pregnant women with confirmed SARS-CoV-2. MATERIAL AND METHODS: A single-unit prospective cohort study in Denmark including pregnant women with SARS-CoV-2 infection confirmed by a pharyngeal swab between August 20, 2020, and March 1, 2021, who gave birth during the same period. All patients admitted to the maternity ward and antepartum clinic were screened for SARS-CoV-2 infection. A maternal blood sample and vaginal swabs were collected at inclusion. If included antepartum, these samples were repeated intrapartum when an umbilical cord blood sample was also collected. Swabs were analyzed for SARS-CoV-2 and blood samples were analyzed for SARS-CoV-2 total antibodies. Placental and neonatal swabs as well as placental histopathological examinations were performed on clinical indications. RESULTS: We included 28 women, of whom four had serious maternal or fetal outcomes including one case of neonatal death. Within the first 8 days after confirmed SARS-CoV-2 infection, SARS-CoV-2 was detectable in two vaginal swabs (2/28) and SARS-CoV-2 antibodies were detected in 1 of 13 women. From 16 days after confirmed infection, antibodies were observed in 19 of 21 of women. Antibodies in cord blood were not detected during the first 16 days after confirmed infection (n = 7). However, from 26 days, antibodies were present in 16 of 17 cord blood samples of seropositive mothers. Placental examination in two cases of severe fetal outcomes preceded by reduced fetal movements revealed SARS-CoV-2 in swabs and severe histopathological abnormalities. CONCLUSIONS: SARS-CoV-2 was detected in only 2 of 28 vaginal swabs within 8 days after confirmed infection in pregnant women. Our data suggest that maternal seroconversion occurs between days 8 and 16, whereas antibodies in cord blood of seropositive mothers were present in the majority from 26 days after confirmed infection. Additional data are needed regarding timing of seroconversion for the mother and appearance of antibodies in cord blood.

Quality of Life in Danish Patients with Multiple Myeloma during the COVID-19 Pandemic

In general, governments and health authorities have taken precautions during the COVID-19 pandemic to reduce the viral spread and protect vulnerable citizens. Patients with multiple myeloma (MM) have an increased risk of being infected with COVID-19 and developing a fatal course due to the related immunodeficiency. We investigated how Danish patients with MM reported their quality of life (QoL) pre-COVID and during COVID, in an ongoing longitudinal QoL survey. The responses given during the first and second wave of the COVID-19 pandemic were pooled, analyzed and compared to the same period the year before. We hypothesized that locking down the society would have caused deteriorated QoL and that patients living alone and those under the age of 65 would be particularly affected by the situation. Surprisingly, our study showed the opposite. Statistically significant and clinically relevant differences were primarily found during the first lock down and represented reduced fatigue, improved role functioning, decreased insomnia and improved physical health summaries in patients below 65 years of age. These results indicate that Danish patients with MM might have felt protected and safe by COVID restrictions. Otherwise, the questionaries used in QoL-MM survey may not have been able to capture the impact of the COVID-19 pandemic. Importantly, this indicates that QoL survey data obtained in clinical studies, in countries with highly developed health-care systems using standard questionnaires during the pandemic, allow room for interpretation without being adjusted for the impacts of the pandemic.

Electronic reporting of diagnostic laboratory test results from all healthcare sectors is a cornerstone of national preparedness and control of COVID-19 in Denmark.

The COVID-19 pandemic has led to an unprecedented demand for real-time surveillance data in order to inform critical decision makers regarding the management of the pandemic. The aim of this review was to describe how the Danish national microbiology database, MiBa, served as a cornerstone for providing data to the real-time surveillance system by linkage to other nationwide health registries. The surveillance system was established on an existing IT health infrastructure and a close network between clinical microbiologists, information technology experts, and public health officials. In 2020, testing capacity for SARS-CoV-2 was ramped up from none to over 10,000 weekly PCR tests per 100,000 population. The crude incidence data mirrored this increase in testing. Real-time access to denominator data and patient registries enabled adjustments for fluctuations testing activity, providing robust data on crude SARS-CoV-2 incidence during the changing diagnostic and management strategies. The use of the same data for different purposes, for example, final laboratory reports, information to the public, contact tracing, public health, and science, has been a critical asset for the pandemic response. It has also raised issues concerning data protection and critical capacity of the underlying technical systems and key resources. However, even with these limitations, the setup has enabled decision makers to adopt timely interventions. The experiences from COVID-19 may motivate a transformation from traditional indicator-based public health surveillance to an all-encompassing information system based on access to a comprehensive set of data sources, including diagnostic and reference microbiology.

Comparison of 16 Serological SARS-CoV-2 Immunoassays in 16 Clinical Laboratories.

Serological assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to support clinical diagnosis and epidemiological investigations. Recently, assays for large-scale detection of total antibodies (Ab), immunoglobulin G (IgG), and IgM against SARS-CoV-2 antigens have been developed, but there are limited data on the diagnostic accuracy of these assays. This study was a Danish national collaboration and evaluated 15 commercial and one in-house anti-SARS-CoV-2 assays in 16 laboratories. Sensitivity was evaluated using 150 samples from individuals with asymptomatic, mild, or moderate COVID-19, nonhospitalized or hospitalized, confirmed by nucleic acid amplification tests (NAAT); samples were collected 13 to 73 days either from symptom onset or from positive NAAT (patients without symptoms). Specificity and cross-reactivity were evaluated in samples collected prior to the SARS-CoV-2 epidemic from >586 blood donors and patients with autoimmune diseases, cytomegalovirus or Epstein-Barr virus infections, and acute viral infections. A specificity of ≥99% was achieved by all total-Ab and IgG assays except one, DiaSorin Liaison XL IgG (97.2%). Sensitivities in descending order were Wantai ELISA total Ab (96.7%), CUH-NOVO in-house ELISA total Ab (96.0%), Ortho Vitros total Ab (95.3%), YHLO iFlash IgG (94.0%), Ortho Vitros IgG (93.3%), Siemens Atellica total Ab (93.2%), Roche Elecsys total Ab (92.7%), Abbott Architect IgG (90.0%), Abbott Alinity IgG (median 88.0%), DiaSorin Liaison XL IgG (median 84.6%), Siemens Vista total Ab (81.0%), Euroimmun/ELISA IgG (78.0%), and Snibe Maglumi IgG (median 78.0%). However, confidence intervals overlapped for several assays. The IgM results were variable, with the Wantai IgM ELISA showing the highest sensitivity (82.7%) and specificity (99%). The rate of seropositivity increased with time from symptom onset and symptom severity.

Clinical presentation and mortality in hospitalized patients aged 80+ years with COVID-19-A retrospective cohort study.

BACKGROUND: COVID-19, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has great health implications in older patients, including high mortality. In general, older patients often have atypical symptom presentations during acute illness due to a high level of comorbidity. The purpose of this study was to investigate the presentation of symptoms at hospital admissions in older patients with COVID-19 and evaluate its impact on disease outcome. METHODS: This retrospective study included patients ≥80 years of age with a positive test for SARS-CoV-2, who were admitted to one of three medical departments in Denmark from March 1st to June 1st, 2020. RESULTS: A total of 102 patients (47% male) with a mean age of 85 years were included. The most common symptoms at admission were fever (74%), cough (62%), and shortness of breath (54%). Furthermore, atypical symptoms like confusion (29%), difficulty walking (13%), and falls (8%) were also present. In-hospital and 30-day mortality were 31% (n = 32) and 41% (n = 42), respectively. Mortality was highest in patients with confusion (50% vs 38%) or falls (63% vs 39%), and nursing home residency prior to hospital admission was associated with higher mortality (OR 2.7, 95% CI 1.1-6.7). CONCLUSIONS: Older patients with SARS-Cov-2 displayed classical symptoms of COVID-19 but also geriatric frailty symptoms such as confusion and walking impairments. Additionally, both in-hospital and 30-day mortality was very high. Our study highlights the need for preventive efforts to keep older people from getting COVID-19 and increased awareness of frailty among those with COVID-19.