Changes in the epidemiological profile of SARS-CoV-2-positive individuals in Mexico across pandemic waves as an explanation of fatality reduction: a retrospective observational study

Objectives
We aim to quantify shifts in hospitalisation and mortality and how those were related to the first three phases of the epidemic and individuals’ demographics and health profile among those with a positive test for SARS-CoV-2 treated at the Mexican Social Security Institute’s facilities from March 2020 to October 2021.

Design
Retrospective observational study using interrupted time series analysis to identify changes in hospitalisation rate and case fatality rate (CFR) by epidemic wave.

Setting
Data from the Mexican Institute of Social Security’s (IMSS) Online Influenza Epidemiological Surveillance System (SINOLAVE) that include all individuals that sought care at IMSS facilities all over Mexico.

Participants
All individuals included in the SINOLAVE with a positive PCR or rapid test for SARS-CoV-2.

Primary and secondary outcome measures
Monthly test positivity rates, hospitalisation rates, CFRs and prevalence of relevant comorbidities by age group.

Results
From March 2020 to October 2021, the CFR declined between 1% and 3.5%; the declines were significant for those 0–9, 20–29, 30–39, 40–49 and 70 and older. The decline was steep during the first wave and was less steep or was temporarily reversed at the beginning of the second and third waves (changes in the trend of about 0.3% and 3.8%, and between 0.7% and 3.8%, respectively, for some age groups), but then continued to the end of the analytical period. Prevalence of diabetes, hypertension and obesity among patients testing positive also declined—two for most age groups (reductions of up to 10 percentage points for diabetes, 12 percentage points for hypertension and 19 percentage points for obesity).

Conclusion
Data suggest that the decrease in COVID-19 fatality rate is at least partially explained by a change in the profile of those contracting the disease, that is, a falling proportion of individuals with comorbidities across all age groups.

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Maggio 2023

Prevalence and impact of SARS-CoV-2 infection on maternal and infant health in African populations: protocol of a multicentre prospective cohort study (MA-CoV project)

Introduction
Pregnant women are currently considered a vulnerable population to SARS-CoV-2 infection, with increased risk of severe COVID-19, preterm birth and maternal mortality. There is, however, a paucity of data on the burden of maternal SARS-CoV-2 infection in sub-Saharan countries. The objective of this study is to determine the prevalence and health effects of maternal SARS-CoV-2 infection in selected sites from Gabon and Mozambique.

Methods and analysis
MA-CoV (MAternal CoVid) is an observational, multicentre prospective cohort study where 1000 pregnant women (500 per country) will be enrolled at the antenatal clinic visits. Participants will undergo monthly follow-up at each antenatal care visit, delivery and postpartum visit. The primary study outcome is the prevalence of SARS-CoV-2 infection during pregnancy. The clinical presentation of COVID-19 in pregnancy will also be characterised, and incidence of infection during pregnancy will be evaluated, as well as the risk factors of maternal and neonatal morbidity and mortality associated with SARS-CoV-2 infection and the risk of mother to child transmission of SARS-CoV-2. SARS-CoV-2 infection screening will be performed through PCR diagnosis.

Ethics and dissemination
The protocol was reviewed and approved by the Comité National d’Éthique pour la Recherche au Gabon, Comité Nacional de Bioética para Saúde de Mocambique and the Ethics Committee of the Hospital Clinic of Barcelona (Spain). Project results will be presented to all stakeholders and published in open access journals.

Trial registration number
NCT05303168.

Leggi
Maggio 2023

Impact of the COVID-19 pandemic on people in need of care or support: protocol for a SARS-CoV-2 registry

Introduction
People in need of care or support are severely affected by the COVID-19 pandemic. We lack valid data of long-term assessments. We present a register study to detect the physical and psychosocial impact of the COVID-19 pandemic on people in need of care or support in Bavaria, Germany. To describe the persons’ life conditions comprehensively, we assess the perspectives and needs of the respective care teams too. Results will serve as evidence-based source to manage the pandemic and long-term prevention strategies.

Methods and analysis
The ‘Bavarian ambulatory COVID-19 Monitor’ is a multicentre registry including a purposive sample of up to 1000 patient–participants across three study sites in Bavaria. The study group consists of 600 people in need of care with a positive SARS-CoV-2 PCR test. Control group 1 comprises 200 people in need of care with a negative SARS-CoV-2 PCR test, while control group 2 comprises 200 people with a positive SARS-CoV-2 PCR test but are not in need of care. We assess the clinical course of infection, psychosocial aspects and care needs using validated measures. Follow-up is every 6 months for up to 3 years. Additionally, we assess up to 400 people linked to these patient–participants (caregivers, general practitioners (GPs)) for their health and needs. Main analyses are stratified by level of care I–V (I=minor/V=most severe impairment of independence), inpatient/outpatient care setting, sex and age. We use descriptive and inferential statistics to analyse cross-sectional data and changes over time. In qualitative interviews with 60 stakeholders (people in need of care, caregivers, GPs, politicians), we explore interface problems of different functional logics, of everyday and professional perspectives.

Ethics and dissemination
The Institutional Review Board of the University Hospital LMU Munich (#20-860) and the study sites (Universities of Wurzburg and Erlangen) approved the protocol. We disseminate the results by peer-reviewed publications, international conferences, governmental reports, etc.

Leggi
Maggio 2023

SARS-CoV-2 vaccination in patients with GI and hepatobiliary carcinoma: a call for booster vaccination

Bollipo et al1 presented recommendations for SARS-CoV-2 infections in patients with chronic liver diseases (CLDs). Since their publication, at least three SARS-CoV-2 vaccinations are recommended for all persons regardless of comorbidities.2 Cancer and CLD are associated with impaired immune responses to SARS-CoV-2 vaccines.3–6 However, patients with GI cancer, especially with hepatobilary carcinoma (HBC), are under-represented in published studies. In this prospective, longitudinal study, 120 patients with GI cancer, including 32.5% HBC, participated (table 1). Patients under anticancer therapy were analysed compared with patients with GI cancer in follow-up care (≥1 year off anticancer therapy). We present profound data on humoral response rates (SARS-CoV-2 antispike and surrogate neutralisation antibodies (sNAB) using SARS-CoV-2 IgG II Quant chemiluminescent microparticle immunoassay (Abbott Laboratories) and cPass SARS-CoV-2 Neutralization Antibody Detection Kit (GenScript), respectively). Of note, the ELISA analysing levels of sNAB…

Leggi
Maggio 2023

Post-acute COVID-19 syndrome and gut dysbiosis linger beyond 1 year after SARS-CoV-2 clearance

We recently published in Gut to show that gut dysbiosis persisted for at least 6 months in patients with post-acute COVID-19 syndrome (PACS).1 Murine and human studies have also reported microbial alterations associated with different PACS symptoms.2 3 With the pandemic entering its third year, PACS could potentially affect recovered individuals for over 1 year.4 It remains unknown whether PACS-associated gut dysbiosis would also linger for such a long time. Here, we conducted a prospective study to determine long-term alterations in the gut microbiome of patients with COVID-19 using shotgun metagenomic sequencing (). A total of 155 patients with COVID-19 in Hong Kong were followed up for an average of 14 months after SARS-CoV-2 viral clearance, and 155 age-matched, sex-matched and body mass index-matched subjects without COVID-19 were recruited as controls. Patients with COVID-19 were infected with the original or earlier variants…

Leggi
Maggio 2023

Validation of a rapid SARS-CoV-2 antibody test in general practice

Objectives
To validate a rapid serological test (RST) for SARS-CoV-2 antibodies used in seroprevalence studies in healthcare providers, including primary healthcare providers (PHCPs) in Belgium.

Design
A phase III validation study of the RST (OrientGene) within a prospective cohort study.

Setting
Primary care in Belgium.

Participants
Any general practitioner (GP) working in primary care in Belgium and any other PHCP from the same GP practice who physically manages patients were eligible in the seroprevalence study. For the validation study, all participants who tested positive (376) on the RST at the first testing timepoint (T1) and a random sample of those who tested negative (790) and unclear (24) were included.

Intervention
At T2, 4 weeks later, PHCPs performed the RST with fingerprick blood (index test) immediately after providing a serum sample to be analysed for the presence of SARS-CoV-2 immunoglobulin G antibodies using a two-out-of-three assay (reference test).

Primary and secondary outcome measures
The RST accuracy was estimated using inverse probability weighting to correct for missing reference test data, and considering unclear RST results as negative for the sensitivity and positive for the specificity. Using these conservative estimates, the true seroprevalence was estimated both for T2 and RST-based prevalence values found in a cohort study with PHCPs in Belgium.

Results
1073 paired tests (403 positive on the reference test) were included. A sensitivity of 73% (a specificity of 92%) was found considering unclear RST results as negative (positive). For an RST-based prevalence at T1 (13.9), T2 (24.9) and T7 (70.21), the true prevalence was estimated to be 9.1%, 25.9% and 95.7%, respectively.

Conclusion
The RST sensitivity (73%) and specificity (92%) make an RST-based seroprevalence below (above) 23% overestimate (underestimate) the true seroprevalence.

Trial registration number
NCT04779424.

Leggi
Maggio 2023

Implementing SARS-CoV-2 antigen testing scale-up in Rwanda: retrospective analysis of national programme data and qualitative findings

Objectives
Reverse transcriptase PCR is the most sensitive test for SARS-CoV-2 diagnosis. However, the scale-up of these tests in low-income and middle-income countries (LMICs) has been limited due to infrastructure and cost. Antigen rapid diagnostic tests are an alternative option for diagnosing active infection that may allow for faster, easier, less expensive and more widespread testing. We compared the implementation of antigen and PCR testing programmes in Rwanda.

Design
We retrospectively reviewed routinely collected PCR and antigen testing data for all reported tests conducted nationally. We administered semiquantitative surveys to healthcare workers (HCWs) involved in COVID-19 testing and care and clients receiving antigen testing.

Setting
Rwanda, November 2020–July 2021.

Participants
National SARS-CoV-2 testing data; 49 HCWs involved in COVID-19 testing and care; 145 clients receiving antigen testing.

Interventions
None (retrospective analysis of programme data).

Primary and secondary outcome measures
Test volumes, turnaround times, feasibility and acceptability of antigen testing.

Results
Data from 906 204 antigen tests and 445 235 PCR tests were included. Antigen testing increased test availability and case identification compared with PCR and had a median results return time of 0 days (IQR: 0–0). In contrast, PCR testing time ranged from 1 to 18 days depending on the sample collection site/district. Both HCWs and clients indicated that antigen testing was feasible and acceptable. Some HCWs identified stockouts and limited healthcare staff as challenges.

Conclusions
Antigen testing facilitated rapid expansion and decentralisation of SARS-CoV-2 testing across lower tier facilities in Rwanda, contributed to increased case identification, reduced test processing times, and was determined to be feasible and acceptable to clients and providers. Antigen testing will be an essential component of SARS-CoV-2 test and treat programmes in LMICs.

Leggi
Aprile 2023

SARS-CoV-2 seroprevalence and living conditions in Bamako (Mali): a cross-sectional multistage household survey after the first epidemic wave, 2020

Objectives
In low-income settings with limited access to diagnosis, COVID-19 information is scarce. In September 2020, after the first COVID-19 wave, Mali reported 3086 confirmed cases and 130 deaths. Most reports originated from Bamako, with 1532 cases and 81 deaths (2.42 million inhabitants). This observed prevalence of 0.06% appeared very low. Our objective was to estimate SARS-CoV-2 infection among inhabitants of Bamako, after the first epidemic wave. We assessed demographic, social and living conditions, health behaviours and knowledges associated with SARS-CoV-2 seropositivity.

Settings
We conducted a cross-sectional multistage household survey during September 2020, in three neighbourhoods of the commune VI (Bamako), where 30% of the cases were reported.

Participants
We recruited 1526 inhabitants in 3 areas, that is, 306 households, and 1327 serological results (≥1 years), 220 household questionnaires and collected answers for 962 participants (≥12 years).

Primary and secondary outcome measures
We measured serological status, detecting SARS-CoV-2 spike protein antibodies in blood sampled. We documented housing conditions and individual health behaviours through questionnaires among participants. We estimated the number of SARS-CoV-2 infections and deaths in the population of Bamako using the age and sex distributions.

Results
The prevalence of SARS-CoV-2 seropositivity was 16.4% (95% CI 15.1% to 19.1%) after adjusting on the population structure. This suggested that ~400 000 cases and ~2000 deaths could have occurred of which only 0.4% of cases and 5% of deaths were officially reported. Questionnaires analyses suggested strong agreement with washing hands but lower acceptability of movement restrictions (lockdown/curfew), and mask wearing.

Conclusions
The first wave of SARS-CoV-2 spread broadly in Bamako. Expected fatalities remained limited largely due to the population age structure and the low prevalence of comorbidities. Improving diagnostic capacities to encourage testing and preventive behaviours, and avoiding the spread of false information remain key pillars, regardless of the developed or developing setting.

Ethics
This study was registered in the registry of the ethics committee of the Faculty of Medicine and Odonto-Stomatology and the Faculty of Pharmacy, Bamako, Mali, under the number: 2020/162/CA/FMOS/FAPH.

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Aprile 2023

Long-term impact on cardiopulmonary function and quality of life among patients recovered from SARS-CoV-2 infection in a 6-month follow-up period in Lima, Peru: FUNCTION cohort study protocol

Introduction
The sequelae of COVID-19 have been described as a multisystemic condition, with a great impact on the cardiovascular and pulmonary systems with abnormalities in pulmonary function tests, such as lower diffusing capacity of the lung for carbon monoxide (DLco) levels and pathological patterns in spirometry; persistence of radiological lesions; cardiac involvement such as myocarditis and pericarditis; and an increase in mental disorders such as anxiety and depression. Several factors, such as infection severity during the acute phase as well as vaccination status, have shown some variable effects on these post-COVID-19 conditions, mainly at a clinical level such as symptoms persistence. Longitudinal assessments and reversibility of changes across the spectrum of disease severity are required to understand the long-term impact of COVID-19.

Methods and analysis
A prospective cohort study aims to assess the impact of SARS-CoV-2 infection on cardiopulmonary function and quality of life after the acute phase of the disease over a 6-month follow-up period. Sample size was calculated to recruit 200 participants with confirmatory COVID-19 tests who will be subsequently classified according to infection severity. Four follow-up visits at baseline, month 1, month 3 and month 6 after discharge from the acute phase of the infection will be scheduled as well as procedures such as spirometry, DLco test, 6-minute walk test, chest CT scan, echocardiogram, ECG, N-terminal pro-B-type natriuretic peptide measurement and RAND-36 scale. Primary outcomes are defined as abnormal pulmonary function test considered as DLco

Leggi
Aprile 2023

COVID-19 vaccine effectiveness and variants in Nepal: study protocol for a test-negative case-control study with SARS-CoV-2 genetic sequencing

Introduction
Inactivated, viral vector and mRNA vaccines have been used in the Nepali COVID-19 vaccination programme but there is little evidence on the effectiveness of these vaccines in this setting. The aim of this study is to describe COVID-19 vaccine effectiveness in Nepal and provide information on infections with SARS-CoV-2 variants.

Methods and analysis
This is a hospital-based, prospective test-negative case–control study conducted at Patan Hospital, Kathmandu. All patients >18 years of age presenting to Patan Hospital with COVID-19-like symptoms who have received a COVID-19 antigen/PCR test are eligible for inclusion. The primary outcome is vaccine effectiveness of licensed COVID-19 vaccines against laboratory-confirmed COVID-19 disease.
After enrolment, information will be collected on vaccine status, date of vaccination, type of vaccine, demographics and other medical comorbidities. The primary outcome of interest is laboratory-confirmed SARS-CoV-2 infection. Cases (positive for SARS-CoV-2) and controls (negative for SARS-CoV-2) will be enrolled in a 1:4 ratio. Vaccine effectiveness against COVID-19 disease will be analysed by comparing vaccination status with SARS-CoV-2 test results.
Positive SARS-CoV-2 samples will be sequenced to identify circulating variants and estimate vaccine effectiveness against common variants.
Measuring vaccine effectiveness and identifying SARS-CoV-2 variants in Nepal will help to inform public health efforts. Describing disease severity in relation to specific SARS-CoV-2 variants and vaccine status will also inform future prevention and care efforts.

Ethics and dissemination
Ethical approval was obtained from the University of Oxford Tropical Ethics Committee (OxTREC) (ref: 561-21) and the Patan Academy of Health Sciences Institutional Review Board (ref: drs2111121578). The protocol and supporting study documents were approved for use by the Nepal Health Research Council (NHRC 550-2021). Results will be disseminated in peer-reviewed journals and to the public health authorities in Nepal.

Leggi
Aprile 2023

Cold Virus Provided Cross-reactivity Against SARS-CoV-2 in Children

Memory CD4 T cells generated after infection with OC43, a common cold coronavirus, also exhibited an immune response against SARS-CoV-2 in early childhood, according to results from 2- and 6-year-old children and adults who did not have antibodies against the novel coronavirus and from a group of adults who had recovered from COVID-19. By age 2 years, many children had antibodies against OC43; by age 6, the reactivity of the CD4 T cells had peaked and then declined in adulthood.

Leggi
Aprile 2023

RECAST: Study protocol for an observational study for the understanding of the increased REsilience of Children compared to Adults in SARS-CoV-2 infecTion

Introduction
The SARS-CoV-2 pandemic remains a threat to public health. Soon after its outbreak, it became apparent that children are less severely affected. Indeed, opposing clinical manifestations between children and adults are observed for other infections. The SARS-CoV-2 outbreak provides the unique opportunity to study the underlying mechanisms. This protocol describes the methods of an observational study that aims to characterise age dependent differences in immune responses to primary respiratory infections using SARS-CoV-2 as a model virus and to assess age differences in clinical outcomes including lung function.

Methods and analysis
The study aims to recruit at least 120 children and 60 adults that are infected with SARS-CoV-2 and collect specimen for a multiomics analysis, including single cell RNA sequencing of nasal epithelial cells and peripheral blood mononuclear cells, mass cytometry of whole blood samples and nasal cells, mass spectrometry-based serum and plasma proteomics, nasal epithelial cultures with functional in vitro analyses, SARS-CoV-2 antibody testing, sequencing of the viral genome and lung function testing. Data obtained from this multiomics approach are correlated with medical history and clinical data. Recruitment started in October 2020 and is ongoing.

Ethics and dissemination
The study was reviewed and approved by the Ethics Committee of Charité – Universitätsmedizin Berlin (EA2/066/20). All collected specimens are stored in the central biobank of Charité – Universitätsmedizin Berlin and are made available to all participating researchers and on request.

Trial registration number
DRKS00025715, pre-results publication.

Leggi
Aprile 2023

Monitoring SARS-CoV-2 incidence and seroconversion among university students and employees: a longitudinal cohort study in California, June-August 2020

Objectives
To identify incident SARS-CoV-2 infections and inform effective mitigation strategies in university settings, we piloted an integrated symptom and exposure monitoring and testing system among a cohort of university students and employees.

Design
Prospective cohort study.

Setting
A public university in California from June to August 2020.

Participants
2180 university students and 738 university employees.

Primary outcome measures
At baseline and endline, we tested participants for active SARS-CoV-2 infection via quantitative PCR (qPCR) test and collected blood samples for antibody testing. Participants received notifications to complete additional qPCR tests throughout the study if they reported symptoms or exposures in daily surveys or were selected for surveillance testing. Viral whole genome sequencing was performed on positive qPCR samples, and phylogenetic trees were constructed with these genomes and external genomes.

Results
Over the study period, 57 students (2.6%) and 3 employees (0.4%) were diagnosed with SARS-CoV-2 infection via qPCR test. Phylogenetic analyses revealed that a super-spreader event among undergraduates in congregate housing accounted for at least 48% of cases among study participants but did not spread beyond campus. Test positivity was higher among participants who self-reported symptoms (incidence rate ratio (IRR) 12.7; 95% CI 7.4 to 21.8) or had household exposures (IRR 10.3; 95% CI 4.8 to 22.0) that triggered notifications to test. Most (91%) participants with newly identified antibodies at endline had been diagnosed with incident infection via qPCR test during the study.

Conclusions
Our findings suggest that integrated monitoring systems can successfully identify and link at-risk students to SARS-CoV-2 testing. As the study took place before the evolution of highly transmissible variants and widespread availability of vaccines and rapid antigen tests, further research is necessary to adapt and evaluate similar systems in the present context.

Leggi
Aprile 2023