Adaptation, spread and transmission of SARS-CoV-2 in farmed minks and associated humans in the Netherlands.

In the first wave of the COVID-19 pandemic (April 2020), SARS-CoV-2 was detected in farmed minks and genomic sequencing was performed on mink farms and farm personnel. Here, we describe the outbreak and use sequence data with Bayesian phylodynamic methods to explore SARS-CoV-2 transmission in minks and humans on farms. High number of farm infections (68/126) in minks and farm workers (>50% of farms) were detected, with limited community spread. Three of five initial introductions of SARS-CoV-2 led to subsequent spread between mink farms until November 2020. Viruses belonging to the largest cluster acquired an amino acid substitution in the receptor binding domain of the Spike protein (position 486), evolved faster and spread longer and more widely. Movement of people and distance between farms were statistically significant predictors of virus dispersal between farms. Our study provides novel insights into SARS-CoV-2 transmission between mink farms and highlights the importance of combining genetic information with epidemiological information when investigating outbreaks at the animal-human interface.

Increasing the Efficiency of a National Laboratory Response to COVID-19: a Nationwide Multicenter Evaluation of 47 Commercial SARS-CoV-2 Immunoassays by 41 Laboratories.

In response to the worldwide pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the subsequent antibody tests that flooded the market, a nationwide collaborative approach in the Netherlands was employed. Forty-one Dutch laboratories joined forces and shared their evaluation data to allow for the evaluation of a quantity of serological assays for SARS-CoV-2 that exceeds the capacity of each individual laboratory. As of April 2020, these performance data had been aggregated and shared in regularly updated reports with other laboratories, Dutch government, public health organizations, and the public. This frequently updated overview of assay performance increased the efficiency of our national laboratory response, supporting laboratories in their choice and implementation of assays. Aggregated performance data for 47 immunoassays for SARS-CoV-2 showed that none of the evaluated immunoassays that detect only IgM or IgA met the diagnostic criteria, indicating that they are not suitable for diagnosing acute infections. For the detection of IgG, only the Biozek Corona virus COVID rapid test, Euroimmun SARS-CoV-2 IgG, and Wantai SARS-CoV-2 antibody (Ab) ELISA met predefined performance criteria in hospitalized patients where samples were collected 14 days post-onset of symptoms (DPO), while for patients with mild or asymptomatic infections, only the Wantai SARS-CoV-2 Ab ELISA met the predefined performance criteria if samples were collected 14 days postonset. Here, we describe this unique nationwide collaboration during the onset of the COVID-19 pandemic; the collected data and their results are an example of what can be accomplished when forces are joined during a public health crisis.

[Experiences of (care) professionals during a COVID-19 outbreak and results of serological tests in the staff of a heavily affected nursing home.] / Ervaringen van (zorg)medewerkers tijdens een COVID-19 uitbraak en resultaten van serologische testen bij personeel in een zwaar getroffen verpleeghuis.

Despite compliance with national (RIVM) guidelines, nursing home Mariënburght (the Netherlands) was severely affected during the first COVID-19 wave: 68 (68%) of the residents were infected. This resulted in a large emotional impact on the (nursing) staff. This study aims to describe the experiences of (nursing) staff, as well as the results of serological tests on COVID-19 that have been administered to professionals. All professionals (n=281) were invited for group interviews to share their experiences concerning the COVID-19 outbreak and for a serological test for COVID-19. The 29 professionals participating in the group interviews mentioned negative and positive experiences about their fear and anxiety, the changed care for residents, the team spirit, the use of personal protective equipment and the testing policy. Out of 240 professionals who underwent the serological test and completed a questionnaire, 94 professionals (39%) had COVID-19 antibodies. In this group, 18 professionals (19%) indicated not having experienced any (physical) complaints related to COVID. Insight into the experiences of professionals resulted in essential learning points, in particular the importance of clear communication with and emotional support for staff. This study also reveals that many professionals of nursing home Mariënburght were affected by COVID-19. An important finding is the high percentage of asymptomatic employees (19% of 94 infected). Our results contributed to changed national testing policies and adapted recommendations in the use of personal protective equipment in nursing homes.