Impact of COVID-19 pandemic on incident diagnosis patterns in German refugee centres: quasi-experimental study, 2018-2023 (preprint)

The COVID-19 pandemic may have affected morbidity patterns of residents in refugee centres, but empirical evidence is scarce. We utilised linked data from a health surveillance network in German refugee centres, employing a quasi-experimental design to examine the effects of the COVID-19 pandemic on newly diagnosed medical conditions. These diagnoses were coded in on-site healthcare facilities for refugee patients. Our analysis encompasses the timeframe from October 2018 to April 2023 and includes individual-level data for 109,175 refugees. This data resulted in 76,289 patient-months across 21 refugee centres, with a total occupancy of 144,012 person-months. We employed segmented regression analyses, adjusting for time trends, socio-demographic factors, centre occupancy, and centre-specific characteristics, to evaluate the COVID-19 pandemic's impact on incident diagnosis patterns among refugees. The COVID-19 pandemic significantly altered diagnosis patterns among refugees in German centres. Notably, incidents of injuries, mental disorders, psychotherapeutic drug prescriptions, and genitourinary diseases rose, while respiratory diseases decreased, later rebounding. An 88% increase in injury-related diagnoses suggests heightened violence experiences during flight or in centres. Mental disorder diagnoses and psychotherapeutic drug prescriptions rose by 73% and 95%, reflecting pandemic-related stressors in refugee centres, highlighting the pandemic's multifaceted impact on refugee health.

COVID-19 among migrants, refugees, and internally displaced persons: systematic review, meta-analysis and qualitative synthesis of the global empirical literature (preprint)

Background: Pandemic response and preparedness plans aim at mitigating the spread of infectious diseases and protecting public health, but migrants are often side-lined. Evidence amounted early that migrants are disproportionately affected by the COVID-19 pandemic and its consequences. However, synthesised evidence is lacking that quantifies the inequalities in infection risk and disease outcomes, or contextualises the consequences of pandemic measures and their underlying mechanisms. Methods: Systematic review searching 25 databases and grey literature (12/2019 to 11/2021). We considered empirical articles covering migrants, refugees, asylum-seekers, and internally displaced persons reporting SARS-CoV-2 cases, hospitalisation, ICU admission, mortality, COVID-19 vaccination rates or health consequences of pandemic measures. Random-effects meta-analysis of observational studies and qualitative analysis were performed for evidence synthesis. A Protocol was registered with PROSPERO (CRD42021296952). Findings: Out of 6956 studies, we included 241 in the review. For the quantitative studies (n=46), meta-analysis with over 40 million study participants showed that compared to non-migrants, migrants have an elevated risk of infection (RR = 2.33; 95%-CI: 1.88-2.89) but similar risk for hospitalisation (RR = 1.05; 0.80-1.37), while the likelihood of ICU admission was higher (RR = 1.36; 1.04-1.78). Among those hospitalised, migrants had a lower risk of mortality (RR = 0.47; 0.30-0.73), while their population-based excess mortality tended to be higher (RR = 1.31; 0.95-1.80). The qualitative synthesis (n=44) highlighted the complex interplay of social and COVID-19-related factors at different levels. This involved increased exposure, risk, and impact of pandemic measures that compromised the health of migrants. Interpretation: Even in the advanced stages of the pandemic, migrants faced higher infection risks and disproportionately suffered from the consequences of COVID-19 disease, including deaths. Population-level interventions in future health emergencies must better consider socio-economic, structural and community-level exposures to mitigate risks among migrants and enhance health information systems, to close coverage gaps in migrant groups.

Impact of non-pharmaceutical interventions on COVID-19 incidence and deaths: cross-national natural experiment in 32 European countries (preprint)

Background Non-pharmaceutical interventions (NPIs) have been the cornerstone of COVID-19 pandemic control, but evidence on their effectiveness mostly stems from the early pandemic phase. Methods We analysed the impact of NPIs on incident SARS-CoV-2 cases and deaths across 32 European countries (March-December 2020). Eight NPI categories were summarized through principal component analysis into three components (C1-3), stratified by two waves (weeks 5-25 and 35-52). Negative binomial regression models were fitted to estimate incidence rate ratios (IRR, 95% confidence intervals, CI) considering time-lags and reverse causation (i.e. changing incidence causing NPIs), stratified by waves and geographical regions. Results During the first wave, restrictions on movement/mobility, public transport, public events, and public spaces (C1) and healthcare system improvements, border closures and restrictions to public institutions (C2) reduced SARS-CoV-2 incidence after 28 and 35-days. Mask policies (C3) reduced SARS-CoV-2 incidence (except after 35-days). During wave 1, C1 and C2 reduced deaths after 49-days and C3 after 21, 28 and 35-days. During wave 2, restrictions on movement/mobility, public transport and healthcare system improvements (C2) decreased SARS-CoV-2 cases and deaths across all countries, while C1 and C3 showed inconsistent effects. Discussion The impact of NPIs on SARS-CoV-2 incidence and deaths varied by regions and waves. In the absence of pre-existing immunity, vaccines or treatment options, masks and healthcare system improvements, border closures and restrictions in public institutions were associated with a reduction in incidence and deaths during wave 1. In wave 2, findings suggest that restrictions in movement/mobility, public transport, and healthcare system improvements effectively reduced incidence.

Covid19 Pandemic Policy Monitor (COV-PPM): European level tracking of non-pharmaceutical interventions (preprint)

The Covid-19 Pandemic Policy Monitor (COV-PPM) prospectively documents the measures taken to contain SARS-Cov-2 transmission across countries in EU27, EEA and UK. In Germany, measures have also been documented at the federal state and, partially, at the district levels. Non-pharmaceutical interventions (NPIs) implemented since March 2020 have been retrieved and updated weekly from official governments webpages, Ministries of Health, National (Public) Health Institutes or Administrations. NPI categories refer to restrictions, closures or changes in functioning implemented in thirteen domains: public events (gatherings in indoor or outdoor spaces); public institutions (kindergartens, schools, universities); public transport (trains, buses, trams, metro); citizens movement/mobility (e.g. pedestrians, cars, ships); border closures (air, land or sea, all incoming travels, from high-risk regions, only non-nationals); measures to improve the healthcare system (e.g. human resources or technical reinforcement, redistribution, material or infrastructural); measures for risk/vulnerable groups (e.g. elderly, chronically ill, pregnant); economic measures (e.g. lay-off rules establishment, actions to avoid job-loss, tax relaxation); testing policies (e.g. testing criteria changes); nose and mouth protection rules, vaccination and others/miscellaneous measures.

Sars-CoV-2 attack rate in reception and accommodation centres for asylum seekers: systematic review of outbreak media reports in Germany (preprint)

Objectives Despite concerns about the impact of the severe acute respiratory syndrome corona virus (Sars-CoV-2) in refugee camps, data on attack rates and effectiveness of containment measures are lacking. We aimed to (1) quantify the attack rate of Sars-CoV-2 during outbreaks in reception and accommodation centres in Germany, (2) assess differences in the attack rate based on containment measures, and (3) provide an overview of testing strategies, communication, conflicts, and protection measures for refugees with special needs. Methods Systematic web-based review of outbreak media reports (until June 2020) on confirmed Sars-CoV-2 cases in reception centers for asylum seekers in Germany using the google search engine. Reports were screened for pre-defined inclusion criteria and complemented by snowball searches. Data on facility name, location, confirmed cases, containment measures, communication, protection strategies, and conflicts was extracted for each outbreak and reporting date. Evidence synthesis: meta-analysis and negative binomial regression. Findings We identified 337 media reports on 101 Sars-CoV-2 outbreaks in 99 reception and accommodation centers in Germany. The pooled Sars-CoV-2 attack rate was 13.1% (95% confidence interval, CI: 9.8- 16.7). Outbreak sites implementing mass quarantine (n=76) showed higher rates (15.7; 95% CI: 11.6 - 20.2) compared to sites using conventional strategies (6.6; 95%CI: 3.1 - 11.2), yielding a rate ratio of 0.44 (95%CI: 0.27-0.72) adjusted for testing strategies, type and size of accommodation. Conflicts occurred in at least 11.8% of all outbreaks. Few sites reported specific measures to protect refugees with special needs. Conclusion Mass quarantine is associated with higher attack rates, and appears to be a counter-productive containment measure in overcrowded camps. Although further research with individual-level data is required to rule out residual confounding, reception centers and refugee camps should follow the available guidelines on Covid-19 response and refrain from mass quarantine if physical distancing cannot be guaranteed.

SARS-Cov-2 prevalence, transmission, health-related outcomes and control strategies in homeless shelters: systematic review and meta-analysis (preprint)

BackgroundPeople experiencing homelessness (PEH) may be at particular risk for COVID19. We synthesised the evidence on SARS-Cov-2 infection, transmission, outcomes of disease, effects of non-pharmaceutical interventions (NPI), and the effectiveness of targeted strategies for infection prevention and control (IPC). MethodsSystematic review of articles, reports and grey-literature indexed in electronic databases (EMBASE, WHO-Covid19, Web of Science), pre-print repositories, institutional websites, and handsearching. Empirical papers of any study design addressing Covid-19 in PEH or homeless shelters staff in English were included. (PROSPERO 2020 CRD42020187033) FindingsOf 194 publications, 13 studies were included (two modelling, ten observational and one qualitative study). All were conducted in high-income countries. Random-effect meta-analysis of prevalence estimates yields a baseline SARS-Cov-2 prevalence of 2{middle dot}14% (95% Confidence-Interval, 95%CI=1{middle dot}02-3{middle dot}27) in PEH and 1{middle dot}72 % (95%CI=0{middle dot}31-3{middle dot}12) in staff. In outbreaks, the pooled prevalence increases to 29{middle dot}49% (95%CI=16{middle dot}44-29{middle dot}55) in PEH and 15{middle dot}18% (95%CI=8{middle dot}95-21{middle dot}42) in staff. Main IPC strategies were universal and rapid testing, expansion of non-congregate housing support, and individual measures in shelters (bed spacing, limited staff rotation). InterpretationUp to 30% PEH and 17% staff are infected during outbreaks of SARS-Cov-2 in homeless shelters. Most studies were conducted in the USA. No studies were found on health-related outcomes or health effects of NPI. An overview and evaluation of IPC strategies for PEH, including a better understanding of disease transmission, and reliable data on PEH within Covid-19 notification systems is needed. Qualitative studies may serve to voice PEH experiences and guide future evaluations and IPC strategies. FundingNo source of funding. Panel 1: Research in contextO_ST_ABSEvidence before this studyC_ST_ABSPeople experiencing homelessness (PEH) are at increased risk of infectious, chronic, and mental health adverse conditions. Due to the risk of transmission in shared accommodations, PEH may be particularly vulnerable to SARS-Cov-2 infection and worse clinical outcomes. Non-pharmaceutical interventions (NPIs) taken to mitigate the SARS-Cov-2 outbreak may have further aggravated health and social conditions. However, there is no evidence synthesis on the SARS-Cov-2 epidemiology among PEH, the correspondent clinical and other health-related outcomes as well as health effects of NPIs on these groups. Added value of this study We reviewed and synthesized existent evidence on the risk of infection and transmission, risk of severe course of disease, effect of NPIs on health outcomes and the effectiveness of implemented measures to avert risks and negative outcomes among PEH. Results of the identified studies suggest that both PEH and shelter staff are at high risk of SARS-Cov-2 infection, especially in case of a local outbreak. Due to the low prevalence of symptoms at the time of a positive SARS-Cov-2 test among PEH, symptom screening alone may not be efficient to control outbreaks. Instead, universal and rapid testing conjugated with expansion of non-congregate housing support, and individual measures in shelters, are discussed as sensible strategies. Implications of all the available evidence A comprehensive overview of NPIs and shelter strategies targeting PEH and evaluation of their effectiveness and unintended health consequences is needed. Qualitative research considering living realities of PEH can facilitate understanding of their specific needs during the pandemic.

SARS-CoV-2 Prevalence, Transmission, Health-Related Outcomes and Control Strategies in Homeless Shelters: Systematic Review and Meta-Analysis (preprint)

Background: People experiencing homelessness (PEH) may be at particular risk for COVID19. We synthesised the evidence on SARS-Cov-2 infection, transmission, outcomes of disease, effects of non-pharmaceutical interventions (NPI), and the effectiveness of targeted strategies for infection prevention and control (IPC). Methods: Systematic review of articles, reports and grey-literature indexed in electronic databases (EMBASE, WHO-Covid19, Web of Science), pre-print repositories, institutional websites, and handsearching. Empirical papers of any study design addressing Covid-19 in PEH or homeless shelters’ staff in English were included. (PROSPERO 2020 CRD42020187033) Findings: Of 194 publications, 13 studies were included (two modelling, ten observational and one qualitative study). All were conducted in high-income countries. Random-effect meta-analysis of prevalence estimates yields a baseline SARS-Cov-2 prevalence of 2·14% (95% Confidence-Interval, 95%CI=1·02-3·27) in PEH and 1·72% (95%CI=0·31-3·12) in staff. In outbreaks, the pooled prevalence increases to 29·49% (95%CI=16·44-29·55) in PEH and 15·18% (95%CI=8·95-21·42) in staff. Main IPC strategies were universal and rapid testing, expansion of non-congregate housing support, and individual measures in shelters (bed spacing, limited staff rotation). Interpretation: Up to 30% PEH and 17% staff are infected during outbreaks of SARS-Cov-2 in homeless shelters. Most studies were conducted in the USA. No studies were found on health-related outcomes or health effects of NPI. An overview and evaluation of IPC strategies for PEH, including a better understanding of disease transmission, and reliable data on PEH within Covid-19 notification systems is needed. Qualitative studies may serve to voice PEH experiences and guide future evaluations and IPC strategies. Funding: No source of funding.Declaration of Interests: The review has been conducted in the scope of the German Competence Net Public Health Covid-19. JS is volunteering (without financial compensation) for a German NGO which provides medical services free of charge for - among others - individuals living in homeless shelters. He further reports membership of the German social democratic party (SPD). The other authors state that they have no competing interests.

Clinical outcomes and risk factors for COVID-19 among migrant populations in high-income countries: a systematic review (preprint)

BackgroundMigrants, including refugees, asylum seekers, labour migrants, and undocumented migrants, now constitute a considerable proportion of most high-income countries populations, including their skilled and unskilled workforces. Migrants may be at increased risk of COVID-19 due to their health and social circumstances, yet the extent to which they are being affected and their predisposing risk factors are not clearly understood. We did a systematic review to assess clinical outcomes of COVID-19 in migrant populations (cases, hospitalisations, deaths), indirect health and social impacts, and to determine key risk factors. MethodsWe did a systematic review following PRISMA guidelines, registered with PROSPERO (CRD42020222135). We searched databases including PubMed, Global Health, Scopus, CINAHL, and pre-print databases (medRxiv) via the WHO Global Research on COVID-19 database to Nov 18, 2020 for peer-reviewed and grey literature pertaining to migrants (defined as foreign born) and COVID-19 in 82 high-income countries. We used our international networks to source national datasets and grey literature. Data were extracted on our primary outcomes (cases, hospitalisations, deaths) and we evaluated secondary outcomes on indirect health and social impacts, and risk factors, using narrative synthesis. Results3016 data sources were screened with 158 from 15 countries included in the analysis (35 data sources for primary outcomes: cases [21], hospitalisations [4]; deaths [15]; 123 for secondary outcomes). We found that migrants are at increased risk of infection and are disproportionately represented among COVID-19 cases. Available datasets suggest a similarly disproportionate representation of migrants in reported COVID-19 deaths, as well as increased all-cause mortality in migrants in some countries in 2020. Undocumented migrants, migrant health and care workers, and migrants housed in camps and labour compounds may have been especially affected. In general, migrants have higher levels of many risk factors and vulnerabilities relevant to COVID-19, including increased exposure to SARS-CoV-2 due to high-risk occupations and overcrowded accommodation, and barriers to health care including inadequate information, language barriers, and reduced entitlement to healthcare coverage related to their immigration status. ConclusionsMigrants in high-income countries are at high risk of exposure to, and infection with, COVID-19. These data are of immediate relevance to national public health responses to the pandemic and should inform policymaking on strategies for reducing transmission of COVID-19 in this population. Robust data on testing uptake and clinical outcomes in migrants, and barriers and facilitators to COVID-19 vaccination, are urgently needed, alongside strengthening engagement with diverse migrant groups.

SARS-CoV-2 among migrants and forcibly displaced populations: a rapid systematic review (preprint)

The economic and health consequences of the COVID-19 pandemic pose a particular threat to vulnerable groups, such as migrants, particularly forcibly displaced populations. The aim of this review is (i) to synthesise the evidence on risk of infection and transmission among migrants, refugees, asylum seekers and internally displaced populations, and (ii) the effect of lockdown measures on these populations. We searched MEDLINE and WOS, preprint servers, and pertinent websites between 1st December 2019 and 26th June 2020. The included studies showed a high heterogeneity in study design, population, outcome and quality. The incidence risk of SARS-CoV-2 varied from 0{middle dot}12% to 2{middle dot}08% in non-outbreak settings and from 5{middle dot}64% to 21{middle dot}15% in outbreak settings. Migrants showed a lower hospitalisation rate compared to non-migrants. Negative impacts on mental health due to lockdown measures were found across respective studies. However, findings show a tenuous and heterogeneous data situation, showing the need for more robust and comparative study designs.

Monitoring the spatiotemporal epidemiology of Covid-19 incidence and mortality: a small-area analysis in Germany (preprint)

Background: As response to the pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), countries worldwide have implemented mitigation and control measures at national and subnational level. Timely monitoring of risks of SARS-CoV-2 incidence and associated deaths at small-area level is essential to inform local response strategies. However, the potentials of spatial epidemiology to contribute to this aim are yet untapped in most countries. Using the example of Germany, we analysed the spatiotemporal epidemiology of SARS-CoV-2 incidence and associated deaths at district level to develop a tool for monitoring incidence and mortality rates and to estimate district-specific risks of disease incidence.   Methods: We conducted a longitudinal small-area analysis for 401 districts to assess the district-specific risks of SARS-CoV-2 incidence by using nationally representative data from the national surveillance system in Germany on a daily basis (January 28 th to May 4 th 2020). We used a Bayesian spatiotemporal model to estimate the district-specific risk ratios (RR) of SARS-CoV-2 incidence and the posterior exceedance probability for RR thresholds greater than 1, 2 or 3, respectively. We further calculated standardised incidence (SIR) and mortality ratios (SMR) stratified by sex and age groups to assess the spatial distribution of SARS-CoV-2 incidence and deaths.   Results: A total of 85 districts (21 % of all districts) showed a RR greater than 3, and 63 districts (16 % of all districts) exceed the RR threshold with a probability of greater than 80 %. Median RR was 1.19 (range 0-523.08), and the median SIR and SMR were 0.34 (range 0-423.94) and 0 (range 0-343.39), respectively. Elevated RR, and correspondingly high SIR and SMR, were observed in at-risk districts (identified by the spatiotemporal model) in southern and western districts of Germany. Daily updates of district-specific risk, SIR and SMR are implemented in a web-based platform. Conclusions: Our approach provides an informative and timely tool to monitor the district-specific risks of SARS-CoV-2 incidence and associated deaths. This approach can be used to inform local authorities for decision-making and strategy planning on containing the SARS-CoV-2 pandemic.