Prevalence of SARS-CoV-2 during the COVID-19 pandemic in Belgium
My PhD will mainly focus on the COVID-19 pandemic. At the end of December 2019, several cases of pneumonia of an unknown origin were reported in Wuhan, China. Not long after, they were declared to be caused by the SARS-CoV-2 virus. The virus started to spread quickly and on the 11th of March 2020, the WHO declared the outbreak as a pandemic. The COVID-19 pandemic had a devastated impact in many nursing homes. Numerous nursing homes in Belgium had outbreaks, which were difficult to control. They reported a high mortality rate, weighing heavily on both residents and staff. In order to control the pandemic in these nursing homes information about cases and deaths is crucial. It is therefore important to know more about the exact prevalence of SARS-CoV-2, not only taking into account residents but also staff, as they come in close contact with these residents. For SARS-CoV-2 virus, reverse-transcriptase polymerase chain reaction (RT-PCR) is used to confirm the diagnosis. The RT-PCR test can therefore help us to determine this prevalence, unfortunately this is suboptimal. Relying only on this test would largely underestimate the number of SARS-CoV-2 infections. Even in elderly, COVID-19 infection sometimes presents with little to no symptoms. When testing is only performed on people with symptoms, people without symptoms are overlooked. Furthermore, in the beginning of the pandemic, the availability of tests was limited. Lastly, the test provides an epidemiological snapshot, failing to identify people who have had the infection, but already cleared the virus. For my doctoral research I will analyze the seroprevalence of SARS-CoV-2 in nursing home residents during the first wave in Belgium, in March 2020. This is highly interesting because during this period the availability of RT-PCR was limited, and hygienic measures applied in nursing homes were sometimes still suboptimal. Besides this I will also take part in the SCOPE study, starting February 2021. This study will examine the seroprevalence of SARS-CoV-2 in nursing home residents and staff before and after vaccination. Subsequently a bimonthly follow-up of the sero-incidence will be performed, this over a period of 10 months. The study design is a longitudinal cohort study with bimonthly interval serial sampling. A total of 1656 nursing home residents and 1380 staff, spread over 69 Belgian nursing homes, will be tested. SARS-CoV-2 antibodies will be determined using a point-of-care (POC) test (COVID-19 IgG/IgM Rapid Test Cassette, Orient Gene Biotech Co) after collection of a capillary blood sample. Additionally, Dry Blood Spot (DBS) collection cards will be used for (semi)quantitative analysis of vaccine-induced/infection-induced antibodies. The covid-19 pandemic is not limited to nursing homes or the elderly. An infection with SARS-CoV-2 virus can lead to severe or critical COVID-19 disease or death in individuals of all age categories. The virus often presents an important diagnostic challenge and determining which patients are at risk for these complications is difficult. For my doctoral research I will participate in a Cochrane review assessing whether existing biomarkers can identify current infection, rule out infection, and can identify people who need critical care. The review will concentrate on the accuracy of routine, blood-based laboratory tests to predict severe to critical COVID-19 disease and death in people with SARS-CoV-2. Identifying the at-risk patients can help clinicians decide whether patients with COVID-19 need to receive either out-of-hospital treatment or need hospitalization, or even intensive care admission.