ABSTRACT
Background People experiencing homelessness (PEH) may be at increased risk of SARS-CoV-2 infection and severe COVID-19. The Dutch government established emergency shelters and introduced preventive measures for homelessness services and there were no major SARS-CoV-2 outbreak noticed among PEH during the first two waves of infections. This study aimed to assess the prevalence of current and past infections among PEH and staff at the end of the second COVID-19 wave by conducting an on-site COVID-19 screening project at homelessness services in Amsterdam, the Netherlands. Methods We assessed the proportion of visitors and staff members of four homelessness services at two locations in Amsterdam with positive SARS-CoV-2 qPCR and antibody results (IgG/IgM Rapid Test, Biozek) in May 2021. We also assessed sociodemographic, clinical and lifestyle characteristics, compliance with basic prevention measures and intention to vaccinate against COVID-19 among PEH and staff.Results A total of 138 visitors and 53 staff members filled out a questionnaire and were tested. Among PEH, the SARS-CoV-2 positivity rate was 0% (0/133;95%CI=0-1.9) and the antibody positivity rate was 1.6% (2/131;95%CI=0.8-7.5). Among staff, these percentages were 3% (1/32;95%CI=0.1-16.2) and 11% (5/53;95%CI=3.6-23.6), respectively. Most participants were frequently compliant with the basic preventive measures ‘not shaking hands’, ‘wearing a face mask’ and ‘washing hands’, but not with ‘physical distancing’. Overall, intention to vaccinate for COVID-19 was low (30% for visitors, 10% for staff) or medium (28% for visitors, 35% for staff). Trust in COVID-19 policies were also, for the most part, low (27% for visitors, 17% for staff) or neutral (32% for visitors, 53% for staff).Conclusions We observed a low prevalence of past and current SARS-CoV-2 infections among PEH, which may be explained by instated shelter policies, limited daily activities of PEH and compliance with certain prevention measures. Vaccine hesitancy and mistrust among visitors and staff could hinder vaccination uptake, suggesting that improvements in public heath communication and interventions towards visitors and staff of homelessness services are needed.
Subject(s)
COVID-19ABSTRACT
ABSTRACT Background It is important to gain insight into the burden of COVID-19 at city district level to develop targeted prevention strategies. We examined COVID-19 related hospitalisations by city district and migration background in the municipality of Amsterdam, the Netherlands. Methods We used surveillance data on all PCR-confirmed SARS-CoV-2 hospitalisations in Amsterdam until 31 May 2020, matched to municipal registration data on migration background. We calculated directly standardised (age, sex) rates (DSR) of hospitalisations, as a proxy of COVID-19 burden, per 100,000 population by city district and migration background. We calculated standardised rate differences (RD) and rate ratios (RR) to compare hospitalisations between city districts of varying socio-economic and health status and between migration backgrounds. We evaluated the effects of city district and migration background on hospitalisation after adjusting for age and sex using Poisson regression. Results Between 29 February and 31 May 2020, 2326 cases (median age 57 years [IQR=37-74]) were notified in Amsterdam, of which 596 (25.6%) hospitalisations and 287 (12.3%) deaths. 526/596 (88.2%) hospitalisations could be matched to the registration database. DSR were higher in individuals living in peripheral (South-East/New-West/North) city districts with lower economic and health status, compared to central districts (Centre/West/South/East) (RD=36.87,95%CI=25.79-47.96;RR=1.82,95%CI=1.65-1.99), and among individuals with a non-Western migration background compared to ethnic-Dutch individuals (RD=57.05,95%CI=43.34-70.75; RR=2.36,95%CI=2.17-2.54). City district and migration background were independently associated with hospitalisation. Conclusion City districts with lower economic and health status and those with a non-Western migration background had the highest burden of COVID-19 during the first wave of COVID-19 in Amsterdam.
Subject(s)
COVID-19ABSTRACT
BackgroundRapid and accurate detection of SARS-CoV-2 infected individuals is crucial for taking timely measures and minimizing the risk of further SARS-CoV-2 spread. We aimed to assess the accuracy of exhaled breath analysis by electronic nose (eNose) for the discrimination between individuals with and without a SARS-CoV-2 infection. MethodsThis was a prospective real-world study of individuals presenting to public test facility for SARS-CoV-2 detection by molecular amplification tests (TMA or RT-PCR). After sampling of a combined throat/nasopharyngeal swab, breath profiles were obtained using a cloud-connected eNose. Data-analysis involved advanced signal processing and statistics based on independent t-tests followed by linear discriminant and ROC analysis. Data from the training set were tested in a validation, a replication and an asymptomatic set. FindingsFor the analysis 4510 individuals were available. In the training set (35 individuals with; 869 without SARS-CoV-2), the eNose sensors were combined into a composite biomarker with a ROC-AUC of 0.947 (CI:0.928-0.967). These results were confirmed in the validation set (0.957; CI:0.942-0.971, n=904) and externally validated in the replication set (0.937; CI:0.926-0.947, n=1948) and the asymptomatic set (0.909; CI:0.879-0.938, n=754). Selecting a cut-off value of 0.30 in the training set resulted in a sensitivity/specificity of 100/78, >99/84, 98/82% in the validation, replication and asymptomatic set, respectively. InterpretationeNose represents a quick and non-invasive method to reliably rule out SARS-CoV-2 infection in public health test facilities and can be used as a screening test to define who needs an additional confirmation test. FundingMinistry of Health, Welfare and Sport Research in contextO_ST_ABSEvidence before this studyC_ST_ABSElectronic nose technology is an emerging diagnostic tool for diagnosis and phenotyping of a wide variety of diseases, including inflammatory respiratory diseases, lung cancer, and infections. As of Feb 13, 2021, our search of PubMed using keywords "COVID-19" OR "SARS-CoV-2" AND "eNose" OR "electronic nose" OR "exhaled breath analysis" yielded 4 articles (1-4) that have assessed test characteristics of electronic nose to diagnose COVID-19. In these small studies the obtained signals using sensor-based technologies, two-dimensional gas chromatography and time-of-flight mass spectrometry, or proton transfer reaction time-of-flight mass spectrometry, provided adequate discrimination between patients with and without COVID-19. Added value of this studyWe prospectively studied the accuracy of exhaled breath analysis by electronic nose (eNose) to diagnose or rule out a SARS-CoV-2 infection in individuals with and without symptoms presenting to a public test facility. In the training set with 904 individuals, the eNose sensors were combined into a composite biomarker with a ROC-AUC of 0.948. In three independent validation cohorts of 3606 individuals in total, eNose was able to reliably rule out SARS-CoV-2 infection in 70-75% of individuals, with a sensitivity ranging between 98-100%, and a specificity between 78-84%. No association was found between cycle thresholds values, as semi-quantitative measure of viral load, and eNose variables. Implications of all the available evidenceThe available findings, including those from our study, support the use of eNose technology to distinguish between individuals with and without a SARS-CoV-2 infection with high accuracy. Exhaled breath analysis by eNose represents a quick and non-invasive method to reliably rule out a SARS-CoV-2 infection in public health test facilities. The results can be made available within seconds and can therefore be used as screening instrument. The eNose can reliably rule out a SARS-CoV-2 infection, eliminating the need for additional time-consuming, stressful, and expensive diagnostic tests in the majority of individuals.