Social inequalities and long-term health impact of COVID-19 in Belgium: protocol of the HELICON population data linkage.

INTRODUCTION: Data linkage systems have proven to be a powerful tool in support of combating and managing the COVID-19 pandemic. However, the interoperability and the reuse of different data sources may pose a number of technical, administrative and data security challenges. METHODS AND ANALYSIS: This protocol aims to provide a case study for linking highly sensitive individual-level information. We describe the data linkages between health surveillance records and administrative data sources necessary to investigate social health inequalities and the long-term health impact of COVID-19 in Belgium. Data at the national institute for public health, Statistics Belgium and InterMutualistic Agency are used to develop a representative case-cohort study of 1.2 million randomly selected Belgians and 4.5 million Belgians with a confirmed COVID-19 diagnosis (PCR or antigen test), of which 108 211 are COVID-19 hospitalised patients (PCR or antigen test). Yearly updates are scheduled over a period of 4 years. The data set covers inpandemic and postpandemic health information between July 2020 and January 2026, as well as sociodemographic characteristics, socioeconomic indicators, healthcare use and related costs. Two main research questions will be addressed. First, can we identify socioeconomic and sociodemographic risk factors in COVID-19 testing, infection, hospitalisations and mortality? Second, what is the medium-term and long-term health impact of COVID-19 infections and hospitalisations? More specific objectives are (2a) To compare healthcare expenditure during and after a COVID-19 infection or hospitalisation; (2b) To investigate long-term health complications or premature mortality after a COVID-19 infection or hospitalisation; and (2c) To validate the administrative COVID-19 reimbursement nomenclature. The analysis plan includes the calculation of absolute and relative risks using survival analysis methods. ETHICS AND DISSEMINATION: This study involves human participants and was approved by Ghent University hospital ethics committee: reference B.U.N. 1432020000371 and the Belgian Information Security Committee: reference Beraadslaging nr. 22/014 van 11 January 2022, available via https://www.ehealth.fgov.be/ehealthplatform/file/view/AX54CWc4Fbc33iE1rY5a?filename=22-014-n034-HELICON-project.pdf. Dissemination activities include peer-reviewed publications, a webinar series and a project website.The pseudonymised data are derived from administrative and health sources. Acquiring informed consent would require extra information on the subjects. The research team is prohibited from gaining additional knowledge on the study subjects by the Belgian Information Security Committee's interpretation of the Belgian privacy framework.

Informal care burden during the COVID-19 pandemic in Flanders, Belgium: The role of perceived threat, personality and resilience.

BACKGROUND: In this study, we investigate how socio-demographic characteristics (age, gender and education) and informal care relationship characteristics (e.g., time spent on care, number of informal caregivers, professional care) are linked with informal care burden during the COVID-19 pandemic. In addition, we expect this burden to differ by personality characteristics, degree of resilience, and-in this specific context-perceived the COVID-19 threat. METHOD: We used the fifth wave of a longitudinal study to identify 258 informal caregivers. These online survey data came from a five-wave longitudinal study in Flanders, Belgium that ran from April 2020 to April 2021. Data were representative of the adult population by age and gender. Analyses include t-tests, ANOVA, SEM and binomial logistic regression. RESULTS: We found that the informal care burden was strongly linked with a socio-economic gradient, time investment changes in care since the start of the pandemic, and whether there was more than one informal caregiver. Personality traits such as agreeableness and openness to experience, and the perceived threat of COVID-19 were also related to care burden. CONCLUSIONS: During the pandemic, informal caregivers were put under extra considerable pressure: restrictive government measures sometimes led to the temporary suspension of some or all professional care for persons with care needs, which may have resulted in a growing psychosocial burden. We recommend that, in the future, the focus should be on supporting the mental wellbeing and social participation of caregivers along with measures to protect caregivers and their relatives from COVID-19. Support structures for informal caregivers should be kept running during crises now and in the future, but it is also important to adopt a case-by-case basis to consider support for informal caregivers.

SARS-CoV-2 infection prevention and control measures in Belgian schools between December 2020 and June 2021 and their association with seroprevalence: a cross-sectional analysis of a prospective cohort study.

BACKGROUND: To protect school-aged children from the potential consequences of a new viral infection, public health authorities recommended to implement infection prevention and control (IPC) measures in school settings. Few studies evaluated the implementation of these measures and their effect on SARS-CoV-2 infection rates among pupils and staff. The aim of this study was to describe the implementation of infection prevention and control (IPC) measures in Belgian schools and assess its relation to the prevalence of anti-SARS-CoV-2 antibodies among pupils and staff. METHODS: We conducted a prospective cohort study in a representative sample of primary and secondary schools in Belgium between December 2020 and June 2021. The implementation of IPC measures in schools was assessed using a questionnaire. Schools were classified according to their compliance with the implementation of IPC measures as 'poor', 'moderate' or 'thorough'. Saliva samples were collected from pupils and staff to determine the SARS-CoV-2 seroprevalence. To assess the association between the strength of implementation of IPC measures and SARS-CoV-2 seroprevalence among pupils and staff, we conducted a cross-sectional analysis using the data collected in December 2020/January 2021. RESULTS: A variety of IPC measures (ventilation, hygiene and physical distancing) was implemented by more than 60% of schools, with most attention placed on hygiene measures. In January 2021, poor implementation of IPC measures was associated with an increase in anti-SARS-CoV-2 antibody prevalence among pupils from 8.6% (95%CI: 4.5 - 16.6) to 16.7% (95%CI: 10.2 - 27.4) and staff from 11.5% (95%CI: 8.1 - 16.4) to 17.6% (95%CI: 11.5 - 27.0). This association was only statistically significant for the assessment of all IPC measures together in the population comprised of pupils and staff. CONCLUSIONS: Belgian schools were relatively compliant with recommended IPC measures at the school level. Higher SARS-CoV-2 seroprevalence among pupils and staff was found in schools with poor implementation of IPC measures, compared to schools with thorough implementation. TRIAL REGISTRATION: This trial is registered under the NCT04613817 ClinicalTrials.gov Identifier on November 3, 2020.

Local initiative supports case isolation and contact tracing during a SARS-CoV-2 surge in summer 2020: a community case study in Antwerp, Belgium.

In Antwerp, Belgium's second largest city, a COVID-19 surge in July 2020 predominantly affected neighborhoods with high ethnic diversity. Local volunteers reacted and set up an initiative to support contact tracing and self-isolation. We describe the origin, implementation, and transfer of this local initiative, based on semi-structured interviews of five key informants and document review. The initiative started in July 2020, when family physicians signaled a surge of SARS-CoV-2 infections among people of Moroccan descent. Family physicians feared that the mainstream contact tracing organized by the Flemish government through centralized call centers would not be efficient in halting this outbreak. They anticipated language barriers, mistrust, inability to investigate case clusters, and practical problems with self-isolation. It took 11 days to start up the initiative, with logistical support from the province and city of Antwerp. Family physicians referred SARS-CoV-2-infected index cases with complex needs (including language and social situation) to the initiative. Volunteer COVID coaches contacted cases, got a contextualized understanding of their living conditions, assisted with backward and forward contact tracing, offered support during self-isolation, and checked if infected contacts also needed support. Interviewed coaches were positive about the quality of the interaction: they described extensive open conversations with cases. The coaches reported back to referring family physicians and coordinators of the local initiative, who took additional action if necessary. Although interactions with affected communities were perceived as good, respondents considered that the number of referrals by family physicians was too low to have a meaningful impact on the outbreak. In September 2020, the Flemish government assigned the tasks of local contact tracing and case support to the local health system level (primary care zones). While doing so, they adopted elements of this local initiative, such as COVID coaches, tracing system, and extended questionnaires to talk with cases and contacts. This community case study illustrates how urgency can motivate people to action yet support from people with access to resources and coordination capacity is vital for effective organization and transition to long-term sustainability. From their conception, health policies should consider adaptability of new interventions to local contexts.

Late miscarriage and stillbirth in asymptomatic and symptomatic hospitalised pregnant women in Belgium during the first and second waves of COVID-19: a prospective nationwide population-based study.

BACKGROUND: Stillbirth has been recognized as a possible complication of a SARS-CoV-2 infection during pregnancy, probably due to destructive placental lesions (SARS-CoV-2 placentitis). The aim of this work is to analyse stillbirth and late miscarriage cases in unvaccinated pregnant women infected with SARS-CoV-2 during the first two waves (wild-type period) in Belgium. METHODS: Stillbirths and late miscarriages in our prospective observational nationwide registry of SARS-CoV-2 infected pregnant women (n = 982) were classified by three authors using a modified WHO-UMC classification system for standardized case causality assessment. RESULTS: Our cohort included 982 hospitalised pregnant women infected with SARS-CoV-2, with 23 fetal demises (10 late miscarriages from 12 to 22 weeks of gestational age and 13 stillbirths). The stillbirth rate was 9.5‰ for singleton pregnancies and 83.3‰ for multiple pregnancies, which seems higher than for the background population (respectively 5.6‰ and 13.8‰). The agreement between assessors about the causal relationship with SARS-Cov-2 infection was fair (global weighted kappa value of 0.66). Among these demises, 17.4% (4/23) were "certainly" attributable to SARS-CoV-2 infection, 13.0% (3/23) "probably" and 30.4% (7/23) "possibly". Better agreement in the rating was noticed when pathological examination of the placenta and identification of the virus were available, underlining the importance of a thorough investigation in case of intra-uterine fetal demise. CONCLUSIONS: SARS-CoV-2 causality assessment of late miscarriage and stillbirth cases in our Belgian nationwide case series has shown that half of the fetal losses could be attributable to SARS-CoV-2. We must consider in future epidemic emergencies to rigorously investigate cases of intra-uterine fetal demise and to store placental tissue and other material for future analyses.

A longitudinal perspective on perceived vulnerability to disease during the COVID-19 pandemic in Belgium.

During the coronavirus disease 2019 pandemic, individuals relied heavily on media sources to stay informed about the disease and public health measures. However, differences exist in the type and frequency of news media consumption, which can be linked to their perceived vulnerability to disease. In this longitudinal study, 1000 Flemish (Belgium) individuals were followed from March 2020 until September 2020, focussing on the evolution in perceived vulnerability to disease (i.e. perceived infectability and germ aversion). Media consumption significantly impacts perceived germ aversion; heavy consumers of commercial media reported greater germ aversion than light consumers of these media. The evolution of germ aversion among individuals from March to August depends on their gender, living environment, age and possibility to work from home. Furthermore, the evolution of perceived infectability depends on the age and living environment of the respondent. These findings may interest policy makers and media professionals to anticipate how anxieties regarding contracting an infectious disease evolve over time and how individual characteristics affect this evolution.

Vaccine effectiveness against transmission of alpha, delta and omicron SARS-COV-2-infection, Belgian contact tracing, 2021-2022.

OBJECTIVES: Vaccine effectiveness against transmission (VET) of SARS-CoV-2-infection can be estimated from secondary attack rates observed during contact tracing. We estimated VET, the vaccine-effect on infectiousness of the index case and susceptibility of the high-risk exposure contact (HREC). METHODS: We fitted RT-PCR-test results from HREC to immunity status (vaccine schedule, prior infection, time since last immunity-conferring event), age, sex, calendar week of sampling, household, background positivity rate and dominant VOC using a multilevel Bayesian regression-model. We included Belgian data collected between January 2021 and January 2022. RESULTS: For primary BNT162b2-vaccination we estimated initial VET at 96% (95%CI 95-97) against Alpha, 87% (95%CI 84-88) against Delta and 31% (95%CI 25-37) against Omicron. Initial VET of booster-vaccination (mRNA primary and booster-vaccination) was 87% (95%CI 86-89) against Delta and 68% (95%CI 65-70) against Omicron. The VET-estimate against Delta and Omicron decreased to 71% (95%CI 64-78) and 55% (95%CI 46-62) respectively, 150-200 days after booster-vaccination. Hybrid immunity, defined as vaccination and documented prior infection, was associated with durable and higher or comparable (by number of antigen exposures) protection against transmission. CONCLUSIONS: While we observed VOC-specific immune-escape, especially by Omicron, and waning over time since immunization, vaccination remained associated with a reduced risk of SARS-CoV-2-transmission.

SARS-CoV-2 infection and COVID19 vaccination across eight immune-mediated inflammatory disorders: A prospective, real-life Belgian cohort study - the BELCOMID study.

Background: The risks and impact of COVID19 disease and vaccination in patients with Immune Mediated Inflammatory Diseases (IMID) remain incompletely understood. IMID patients and particularly patients receiving immunosuppressive treatment were excluded from the original, registrational phase-3 COVID19 vaccination efficacy and safety trials. Real-world observational data can help to fill this gap in knowledge. The BELCOMID study aims to explore the interaction between IMIDs, immune-modulating treatment modalities and SARS-CoV-2 infection and vaccination in a real-life patient cohort. Methods: A multidisciplinary, prospective, observational cohort study was set up. Consecutive patients with IMIDs of the gut, joints and skin followed at two high-volume referral centers were invited. Both patients under conventional treatment or targeted immune modulating therapies were included. Patient data and serological samples were collected at 3 predefined periods (before COVID19 vaccination, before booster vaccination, after booster vaccination). Primary endpoints were positive PCR-test and SARS-CoV-2 serology reflecting previous SARS-CoV-2 infection or vaccination. Associations with IMID treatment modality and IMID disease activity were assessed. Results of the first two inclusion periods (before booster vaccination) are reported. Results: At the first inclusion period data was assessed of 2165 IMID-patients before COVID19 vaccination. At the second inclusion period, data of 2065 patients was collected of whom 1547 had received complete baseline COVID19 vaccination and 222 were partially vaccinated. SARS-CoV-2 infection rate remained low in both groups. No significant increase in IMID flare-up rate was noted in patients with prior SARS-CoV-2 infection. Multiple logistic regression analyses did not show a significant influence of IMID-treatment modality or IMID activity on SARS-CoV-2 infection risk (based on PCR positivity or N-serology). Patients treated with conventional immunomodulators, systemic steroids, and patients on advanced therapies such as biologics or small molecules, had reduced S-antibody seroconversion. S-antibody response was also lower in patients without prior SARS-CoV-2 infection and in active smokers. A subset of patients (4.1%) had no S- nor N-antibody seroconversion following complete baseline vaccination. Conclusion: The BELCOMID study results confirm the benign course of COVID19 infection and vaccination in a large real-life IMID-population. However, our results underscore the need for repeated vaccination and smoking cessation in patients with IMIDs treated with immune-modulating therapies or systemic steroids during the pandemic.

Sub-Saharan African communities' experiences and engagement with COVID-19 and the related control strategies in Antwerp, Belgium.

BACKGROUND: Pre-existing racial/ethnic disparities in health, sustained by intersecting socio-economic and structural inequities, have widened due to the COVID-19 pandemic. Yet, little attention has been paid to the lived experiences of people in ethnic/racialised minority communities, and to the causes and effects underlying the COVID-19-related burden. This hinders tailored responses. This study explores Sub-Saharan African (SSA) communities' needs, perceptions, and experiences of the COVID-19 pandemic and its control measures in Antwerp (Belgium) in 2020. METHODS: This qualitative study using an interpretative ethnographical approach adopted an iterative and participatory methodology: a community advisory board advised on all stages of the research process. Interviews and a group discussion were conducted online, through telephone, and face-to-face. We analysed the data inductively using a thematic analytical approach. RESULTS: Our respondents, who mostly used social media for information, struggled with misinformation about the new virus and prevention measures. They reported to be vulnerable to misinformation about the origin of the pandemic, risk of infection with SARS-CoV-2, and the prevention measures. Not only did the epidemic affect SSA communities, but to a larger extent, the control strategies did-especially the lockdown. Respondents perceived the interaction of social factors (i.e. being migrants, being undocumented, having experienced racism and discrimination) and economic factors (i.e. working in temporary and precarious jobs, not being able to apply for unemployment benefit, crowded housing conditions) as increasing the burden of COVID-19 control measures. In turn, these experiences influenced people's perceptions and attitudes, and may have partially impaired them to follow some public health COVID-19 prevention guidelines. Despite these challenges, communities developed bottom-up initiatives to react quickly to the epidemic, including translation of prevention messages, food distribution, and online spiritual support. CONCLUSION: Pre-existing disparities influenced the perceptions of and attitudes towards COVID-19 and its control strategies among SSA communities. To better design support and control strategies targeted to specific groups, we need to not only involve communities and address their specific needs and concerns, but also build on their strengths and resilience. This will remain important in the context of widening disparities and future epidemics.

Surfing the Waves: Differences in Hospitalised COVID-19 Patients across 4 Variant Waves in a Belgian University Hospital.

The unprecedented COVID-19 pandemic took the form of successive variant waves, spreading across the globe. We wanted to investigate any shift in hospitalised patients' profiles throughout the pandemic. For this study, we used a registry that collected data automatically from electronic patient health records. We compared clinical data and severity scores, using the National Institute of Health (NIH) severity scores, from all patients admitted for COVID-19 during four SARS-CoV-2 variant waves. Our study concluded that patients hospitalised for COVID-19 showed very different profiles across the four variant waves in Belgium. Patients were younger during the Alpha and Delta waves and frailer during the Omicron period. 'Critical' patients according to the NIH criteria formed the largest fraction among the Alpha wave patients (47.7%), while 'severe' patients formed the largest fraction among Omicron patients (61.6%). We discussed host factors, vaccination status, and other confounders to put this into perspective. High-quality real-life data remain crucial to inform stakeholders and policymakers that shifts in patients' clinical profiles have an impact on clinical practice.

Fractal dimension based geographical clustering of COVID-19 time series data.

Understanding the local dynamics of COVID-19 transmission calls for an approach that characterizes the incidence curve in a small geographical unit. Given that incidence curves exhibit considerable day-to-day variation, the fractal structure of the time series dynamics is investigated for the Flanders and Brussels Regions of Belgium. For each statistical sector, the smallest administrative geographical entity in Belgium, fractal dimensions of COVID-19 incidence rates, based on rolling time spans of 7, 14, and 21 days were estimated using four different estimators: box-count, Hall-Wood, variogram, and madogram. We found varying patterns of fractal dimensions across time and location. The fractal dimension is further summarized by its mean, variance, and autocorrelation over time. These summary statistics are then used to cluster regions with different incidence rate patterns using k-means clustering. Fractal dimension analysis of COVID-19 incidence thus offers important insight into the past, current, and arguably future evolution of an infectious disease outbreak.

Factors associated with problematic substance use before and during the COVID-19 pandemic among a drug addiction recovery cohort: A prospective study in the Netherlands, Belgium, and UK.

BACKGROUND: The COVID-19 pandemic and measures have placed various burdens on societies and individuals. Emerging evidence suggests that people in drug addiction recovery were negatively affected. This study investigates whether risk and protective factors associated with return to problematic substance use differed between the periods before and during the pandemic for those in recovery. METHODS: A convenience sample of persons in drug addiction recovery for at least three months completed an assessment at baseline before the pandemic (T0, N = 367) and at two consecutive follow-ups 12 months apart (T1, N = 311; T2, N = 246). The final follow-up took place during the pandemic (2020-2021). We analyzed rates and predictors of problematic substance use in both periods, and whether relations between predictors and problematic use differed between the periods. RESULTS: Rates of problematic use did not differ significantly before and during the pandemic for those who were followed-up. However, the relationship between problematic use and commitment to sobriety differed between both periods (OR = 3.24, P = 0.010), as higher commitment was only associated with lower odds of problematic use during (OR = 0.27, P < 0.001), but not before, the pandemic (OR = 0.93, P = 0.762). In both periods, persons who were engaged in psychosocial support had lower odds of problematic use. CONCLUSIONS: The COVID-19 pandemic was not followed by significant return to problematic substance use in a cohort of people who were already in drug addiction recovery for some time before the pandemic. However, with restricted access to environmental resources, they may have been more dependent on internal motivations. Targeting personal recovery resources with interventions could therefore reduce the chances of return to problematic substance use during a pandemic.

Mobility and the spatial spread of sars-cov-2 in Belgium.

We analyse and mutually compare time series of covid-19-related data and mobility data across Belgium's 43 arrondissements (NUTS 3). In this way, we reach three conclusions. First, we could detect a decrease in mobility during high-incidence stages of the pandemic. This is expressed as a sizeable change in the average amount of time spent outside one's home arrondissement, investigated over five distinct periods, and in more detail using an inter-arrondissement "connectivity index" (CI). Second, we analyse spatio-temporal covid-19-related hospitalisation time series, after smoothing them using a generalise additive mixed model (GAMM). We confirm that some arrondissements are ahead of others and morphologically dissimilar to others, in terms of epidemiological progression. The tools used to quantify this are time-lagged cross-correlation (TLCC) and dynamic time warping (DTW), respectively. Third, we demonstrate that an arrondissement's CI with one of the three identified first-outbreak arrondissements is correlated to a substantial local excess mortality some five to six weeks after the first outbreak. More generally, we couple results leading to the first and second conclusion, in order to demonstrate an overall correlation between CI values on the one hand, and TLCC and DTW values on the other. We conclude that there is a strong correlation between physical movement of people and viral spread in the early stage of the sars-cov-2 epidemic in Belgium, though its strength weakens as the virus spreads.

Spatio-temporal model to investigate COVID-19 spread accounting for the mobility amongst municipalities.

The rapid spread of COVID-19 worldwide led to the implementation of various non-pharmaceutical interventions to limit transmission and hence reduce the number of infections. Using telecom-operator-based mobility data and a spatio-temporal dynamic model, the impact of mobility on the evolution of the pandemic at the level of the 581 Belgian municipalities is investigated. By decomposing incidence, particularly into within- and between-municipality components, we noted that the global epidemic component is relatively more important in larger municipalities (e.g., cities), while the local component is more relevant in smaller (rural) municipalities. Investigation of the effect of mobility on the pandemic spread showed that reduction of mobility has a significant impact in reducing the number of new infections.

Predicting and comparing COVID-19 risk perceptions across the Netherlands and Belgium: A cross-sectional survey among university students.

People's risk perception of COVID-19 is an important predictor for adopting protective behavior. Although risk perceptions, and factors influencing these, may vary between countries, less attention has been paid to differences between adjacent regions from neighboring countries. In the midst of the first wave of the corona outbreak (March-April-May 2020), we measured risk perceptions as perceived threat (consisting of perceived severity and susceptibility) among university students (N = 668) in two connected countries: the Netherlands and Belgium. Theory-based predictor variables included experiential, efficacy-related, socio-cultural, cognitive, and demographic factors. While demographic variables and country were not significant predictors of perceived threat level, all other constructs were. Personal and indirect experiences with COVID-19, as well as higher scores on personal (self) efficacy to carry out recommended preventive behaviors were all associated with higher perceived threat. However, low collective efficacy and lower levels of trust in government were both also significantly associated with higher perceived threat, as was a low level of "lack of COVID-19 knowledge". These results hold implications for suitable risk communication strategies for increasing students' COVID-19 risk perceptions.

The role of biostatistics in the response to COVID-19: a Belgian and international perspective.

In this commentary to Dattner et al. (Israel J Health Policy Res. 11:22, 2022), we highlight similarities and differences in the role that biostatistics and biostatisticians have been playing in the COVID-19 response in Belgium and Israel. We bring out implications and opportunities for our field and for science. We argue that biostatistics has an important place in the multidisciplinary COVID-19 response, in terms of research, policy advice, and science and public communication. In Belgium, biostatisticians located in various institutes, collaborated with epidemiologists, vaccinologists, infectiologists, immunologists, social scientists, and government policy makers to provide rapid and science-informed policy advice. Biostatisticians, who can easily be mobilized to work together in pandemic response, also played a role in public communication.

COVID-19 Clusters in Belgian Nursing Homes: Impact of Facility Characteristics and Vaccination on Cluster Occurrence, Duration and Severity.

COVID-19 severely affected nursing home residents from March 2020 onwards in Belgium. This study aimed to model the impact of vaccination and facility characteristics on cluster occurrence, duration and severity in this setting. Possible clusters were identified between June 2020 and January 2022, based on the Belgian COVID-19 surveillance in nursing homes. Median attack rates (AR) among residents and staff, case hospitalization rates (CHR) and case fatality rates (CFR) were calculated. A negative binomial model was used to identify the association between nursing home characteristics and the number of cases, hospital admissions and deaths and the duration of the cluster. A total of 2239 clusters were detected in more than 80% of nursing homes. Most of these (62%) occurred before the start of COVID-19 vaccination (end of December 2020). After vaccination, the number of clusters, the AR among residents and staff, the CHR and the CFR dropped. Previous cluster(s) and vaccination decreased the number of cases, hospital admissions and deaths among residents. Previous cluster experience and having started vaccination were protective factors. We recommend continued implementation of targeted interventions such as vaccination, large-scale screening and immediate implementation of additional infection prevention and control measures.

Impact of COVID-19 on the Belgian HIV epidemic: slowdown of HIV transmission and testing and adaptation of care.

BACKGROUND: To gain insight into the impact of the COVID-19 pandemic and containment measures on the HIV epidemic and services, this study aims to describe HIV trends in 2020 and compare them with previous years. METHODS: Belgian national HIV surveillance data 2017-2020 were analysed for trends in HIV testing, HIV diagnoses, VL measurements, ART uptake and PrEP purchase. Descriptive statistics from 2020 are compared to annual averages from 2017 to 2019 (proportional difference, %). RESULTS: In 2020, 725 HIV infections were diagnosed in Belgium (- 21.5% compared to 2019). The decline was most pronounced during the first lockdown in April-May but also present in July-December. The number of HIV tests performed decreased by 17.6% in 2020, particularly in March-May and October-December (- 57.5% in April and -25.4% in November 2020 compared to monthly 2017-19 numbers). Diagnosis of acute HIV infections decreased by 47.1% in 2020 (n = 27) compared to 2019 (n = 51). Late HIV diagnoses decreased by 24.7% (95% CI [- 40.7%; -9.7%]) in 2020 compared to 2019. Of patients in care in 2019, 11.8% interrupted HIV care in 2020 compared to 9.1% yearly in the 3 previous years. The number of HIV patients with VL monitoring per month dropped in March-May 2020, whilst proportions of VL suppression and ART coverage remained above 86% and 98.5% respectively in 2020. PrEP purchases, number of purchasers and starters dropped during April-May 2020 (respectively - 45.7%, - 47.4%, - 77.9% in April compared to February 2020). CONCLUSIONS: The significant decrease in HIV diagnoses in Belgium in 2020 coincided with the COVID-19 pandemic and following containment measures, particularly in April-May during the first lockdown. A slowdown of HIV transmission due to reduced HIV risk exposure is suggested by the halving in diagnosis of acute HIV infections in March-December 2020 compared to the previous year, and the adaptive decrease in PrEP use and PrEP initiation from April onwards. Despite a slight increase in HIV care interruptions, the indicators of quality of HIV care remained stable. Access to prevention, testing and care for all people living with HIV and at risk of acquiring HIV is a priority during and after times of pandemic.

Evaluating methodological approaches to assess the severity of infection with SARS-CoV-2 variants: scoping review and applications on Belgian COVID-19 data.

BACKGROUND: Differences in the genetic material of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants may result in altered virulence characteristics. Assessing the disease severity caused by newly emerging variants is essential to estimate their impact on public health. However, causally inferring the intrinsic severity of infection with variants using observational data is a challenging process on which guidance is still limited. We describe potential limitations and biases that researchers are confronted with and evaluate different methodological approaches to study the severity of infection with SARS-CoV-2 variants. METHODS: We reviewed the literature to identify limitations and potential biases in methods used to study the severity of infection with a particular variant. The impact of different methodological choices is illustrated by using real-world data of Belgian hospitalized COVID-19 patients. RESULTS: We observed different ways of defining coronavirus disease 2019 (COVID-19) disease severity (e.g., admission to the hospital or intensive care unit versus the occurrence of severe complications or death) and exposure to a variant (e.g., linkage of the sequencing or genotyping result with the patient data through a unique identifier versus categorization of patients based on time periods). Different potential selection biases (e.g., overcontrol bias, endogenous selection bias, sample truncation bias) and factors fluctuating over time (e.g., medical expertise and therapeutic strategies, vaccination coverage and natural immunity, pressure on the healthcare system, affected population groups) according to the successive waves of COVID-19, dominated by different variants, were identified. Using data of Belgian hospitalized COVID-19 patients, we were able to document (i) the robustness of the analyses when using different variant exposure ascertainment methods, (ii) indications of the presence of selection bias and (iii) how important confounding variables are fluctuating over time. CONCLUSIONS: When estimating the unbiased marginal effect of SARS-CoV-2 variants on the severity of infection, different strategies can be used and different assumptions can be made, potentially leading to different conclusions. We propose four best practices to identify and reduce potential bias introduced by the study design, the data analysis approach, and the features of the underlying surveillance strategies and data infrastructure.

The Impact of the COVID-19 Crisis on the Practices and Mental Health of Psychologists in Belgium: Between Exhaustion and Resilience.

While the COVID-19 pandemic has created psychological distress in the general population and increased the need for psychological care, little research has been done on how mental health practitioners (MHP) have been affected by the pandemic, and these health professionals have received little attention from public authorities. In this article, we focus on psychologists and the impact that the pandemic has had on their mental health and practices by exploring the adaptive and innovative responses generated. This study is based on an online survey (including multiple choice questions, several validated scales, and eight free text items) completed by 187 psychologists (86% female) one year after the beginning of the COVID-19 pandemic in Belgium (February-April 2021). Most participants considered that the crisis had an impact on their well-being and mental health. However, the prevalence of symptoms of depression and anxiety was relatively low (17%; 12%). On the other hand, the majority of psychologists (72%) suffered from a medium level of burnout (BO), 7% suffered from a high level of BO, and only 21% had low levels of BO. Psychologists working in face-to-face settings had the highest scores on the "exhaustion" subscale of the BO, and those working primarily with patients in precarious situations had significantly higher scores of BO and exhaustion. Qualitative analysis of free text items showed that MHP were resilience and developed new frameworks and modes for proactive interventions in order to reach their patients, meet the psychological and social population's needs, and maintain their relationships with the network. In a crisis or pandemic context, public policies should take into account the psychological and social needs of the most socially precarious populations in reinforcing and supporting mental health professionals working in this sector.