Schistosome infection among pregnant women in the rural highlands of Madagascar: A cross-sectional study calling for public health interventions in vulnerable populations

INTRODUCTION

Schistosomiasis is a parasitic infection highly prevalent in sub-Saharan Africa (SSA) with Madagascar being among the countries with highest burden of the disease worldwide. Despite WHO recommendations, suggesting treatment of pregnant women after the first trimester, this group is still excluded from Mass Drug Administration programs. Our study, had the objective to measure the prevalence of schistosome infection among pregnant women in Madagascar in order to inform public health policies for treatment in this vulnerable population.

METHODS

Women were recruited for this cross-sectional study between April 2019 and February 2020 when attending Antenatal Care Services (ANCs) at one of 42 included Primary Health Care Centers. The urine-based upconverting reporter particle, lateral flow (UCP-LF) test detecting circulating anodic antigen was used for the detection of schistosome infections. To identify factors associated with the prevalence of schistosome infection crude and adjusted prevalence ratios and 95% CIs were estimated using mixed-effect Poisson regression.

RESULTS

Among 4,448 participating women aged between 16 and 47 years, the majority (70.4%, 38 n = 3,133) resided in rural settings. Overall, the prevalence of schistosome infection was 55.9% (n = 2486, CI 95%: 53.3-58.5). A statistically significant association was found with age group (increased prevalence in 31-47 years old, compared to 16-20 years old (aPR = 1.15, CI 95%: 1.02-1.29) and with uptake of antimalaria preventive treatment (decreased prevalence, aPR = 0.85, CI 95%: 0.77-0.95). No other associations of any personal characteristics or contextual factors with schistosome infection were found in our multivariate regression analysis.

DISCUSSION AND CONCLUSION

The high prevalence of schistosome infection in pregnant women supports the consideration of preventive schistosomiasis treatment in ANCs of the Malagasy highlands. We strongly advocate for adapting schistosomiasis programs in highly endemic contexts. This, would contribute to both the WHO and SDGs agendas overall to improving the well-being of women and consequently breaking the vicious cycle of poverty perpetuated by schistosomiasis.

COVID-19 vaccine effectiveness against symptomatic infection with SARS-CoV-2 BA.1/BA.2 lineages among adults and adolescents in a multicentre primary care study, Europe, December 2021 to June 2022

BackgroundScarce European data in early 2021 suggested lower vaccine effectiveness (VE) against SARS-CoV-2 Omicron lineages than previous variants.AimWe aimed to estimate primary series (PS) and first booster VE against symptomatic BA.1/BA.2 infection and investigate potential biases.MethodsThis European test-negative multicentre study tested primary care patients with acute respiratory symptoms for SARS-CoV-2 in the BA.1/BA.2-dominant period. We estimated PS and booster VE among adults and adolescents (PS only) for all products combined and for Comirnaty alone, by time since vaccination, age and chronic condition. We investigated potential bias due to correlation between COVID-19 and influenza vaccination and explored effect modification and confounding by prior SARS-CoV-2 infection.ResultsAmong adults, PS VE was 37% (95% CI: 24-47%) overall and 60% (95% CI: 44-72%), 43% (95% CI: 26-55%) and 29% (95% CI: 13-43%) < 90, 90-179 and ≥ 180 days post vaccination, respectively. Booster VE was 42% (95% CI: 32-51%) overall and 56% (95% CI: 47-64%), 22% (95% CI: 2-38%) and 3% (95% CI: -78% to 48%), respectively. Primary series VE was similar among adolescents. Restricting analyses to Comirnaty had little impact. Vaccine effectiveness was higher among older adults. There was no signal of bias due to correlation between COVID-19 and influenza vaccination. Confounding by previous infection was low, but sample size precluded definite assessment of effect modification.ConclusionPrimary series and booster VE against symptomatic infection with BA.1/BA.2 ranged from 37% to 42%, with similar waning post vaccination. Comprehensive data on previous SARS-CoV-2 infection would help disentangle vaccine- and infection-induced immunity.

Health beliefs and attitudes toward Influenza and COVID-19 vaccination in Portugal: a study using a mixed-method approach

Introduction

Vaccination is one of the most effective population strategies to prevent infectious diseases and mitigate pandemics, and it is important to understand vaccine uptake determinants since vaccine hesitancy has been increasing for the past few decades. The Health Belief Model (HBM) has been widely used for understanding vaccination behavior. The current study aimed to assess influenza vaccine (IV) non-uptake and attitudes toward COVID-19 vaccination, two important respiratory diseases with similar symptoms, and routes of transmission in the Portuguese population.

Methods

We conducted a cross-sectional study using a panel sample of randomly chosen Portuguese households. A total of 1,050 individuals aged 18 years and over responded to a telephone or online questionnaire. Through a mixed-method approach, we employed thematic content analysis to describe reasons for not taking the IV, considering the HBM dimensions, and quantitative statistical analysis to estimate IV and COVID-19 vaccine coverage.

Results

The IV uptake for the overall population was 30.7% (CI 95%: 26.5, 35.2). Susceptibility was found to be a main factor for IV non-uptake, followed by barriers, such as stock availability and fear of adverse effects. The uptake of the COVID-19 vaccine was very high in the study population (83.1%, CI 95%: 13.6%-20.9%). There was a high perception of COVID-19-associated severity and fear of the consequences. Individuals who reported IV uptake seemed to perceive a higher severity of COVID-19 and a higher benefit of taking the COVID-19 vaccine for severe complications.

Discussion

Thus, the population does not seem to consider influenza to be a health risk, as opposed to COVID-19, which is considered to be a possibly severe disease. The association between IV uptake and COVID-19 perceptions highlights that an overall attitude toward vaccination in general may be an important individual determinant.

End of season 2022/2023 quadrivalent influenza vaccine effectiveness in preventing influenza in primary care in Portugal

Using a test-negative case-control design, we aim to estimate influenza vaccine effectiveness (VE) against medically attended laboratory-confirmed influenza in Portugal in 2022/2023 season. Between week 41/2022 and week 14/2023, data on 592 patients with influenza-like illness aged 18 or more years old were collected by the national sentinel influenza surveillance system in primary care settings. Of those, 218 were positive for influenza and 374 were negative controls. We estimated seasonal influenza VE as (1-odds ratio)*100% of being vaccinated in laboratory-confirmed influenza cases vs. negative controls using logistic regression model adjusted for age group, sex, presence of chronic conditions, and month of symptoms onset. The seasonal VE was 59.3% (95% confidence interval (CI): 27.3 to 77.3) against any laboratory-confirmed influenza and not statistically significant 44.5% (95% CI: -5.6 to 70.8) against influenza A (H3N2). In the 2022/2023 season, characterized by early and low influenza activity and predominant A (H3N2) circulation, vaccination provided a moderate protection against medically attended laboratory-confirmed influenza in primary care.

Portuguese Heart Failure Prevalence Observational Study (PORTHOS) rationale and design - A population-based study

INTRODUCTION AND OBJECTIVES

Current epidemiological data on heart failure (HF) in Portugal derives from studies conducted two decades ago. The main aim of this study is to determine HF prevalence in the Portuguese population. Using current standards, this manuscript aims to describe the methodology and research protocol applied.

METHODS

The Portuguese Heart Failure Prevalence Observational Study (PORTHOS) is a large, three-stage, population-based, nationwide, cross-sectional study. Community-dwelling citizens aged 50 years and older will be randomly selected via stratified multistage sampling. Eligible participants will be invited to attend a screening visit at a mobile clinic for HF symptom assessment, anthropomorphic assessment, N-terminal pro-B-type natriuretic peptide (NT-proBNP) testing, one-lead electrocardiogram (ECG) and a sociodemographic and health-related quality of life questionnaire (EQ-5D). All subjects with NT-proBNP ≥125 pg/mL or with a prior history of HF will undergo a diagnostic confirmatory assessment at the mobile clinic composed of a 12-lead ECG, comprehensive echocardiography, HF questionnaire (KCCQ) and blood sampling. To validate the screening procedure, a control group will undergo the same diagnostic assessment. Echocardiography results will be centrally validated, and HF diagnosis will be established according to the European Society of Cardiology HF guidelines. A random subsample of patients with an equivocal HF with preserved ejection fraction diagnosis based on the application of the Heart Failure Association preserved ejection fraction diagnostic algorithm will be invited to undergo an exercise echocardiography.

CONCLUSIONS

Through the application of current standards, appropriate methodologies, and a strong research protocol, the PORTHOS study will determine the prevalence of HF in mainland Portugal and enable a comprehensive characterization of HF patients, leading to a better understanding of their clinical profile and health-related quality of life.

Vaccine effectiveness against COVID-19 hospitalisation in adults (≥ 20 years) during Omicron-dominant circulation: I-MOVE-COVID-19 and VEBIS SARI VE networks, Europe, 2021 to 2022

IntroductionThe I-MOVE-COVID-19 and VEBIS hospital networks have been measuring COVID-19 vaccine effectiveness (VE) in participating European countries since early 2021.AimWe aimed to measure VE against PCR-confirmed SARS-CoV-2 in patients ≥ 20 years hospitalised with severe acute respiratory infection (SARI) from December 2021 to July 2022 (Omicron-dominant period).MethodsIn both networks, 46 hospitals (13 countries) follow a similar test-negative case-control protocol. We defined complete primary series vaccination (PSV) and first booster dose vaccination as last dose of either vaccine received ≥ 14 days before symptom onset (stratifying first booster into received < 150 and ≥ 150 days after last PSV dose). We measured VE overall, by vaccine category/product, age group and time since first mRNA booster dose, adjusting by site as a fixed effect, and by swab date, age, sex, and presence/absence of at least one commonly collected chronic condition.ResultsWe included 2,779 cases and 2,362 controls. The VE of all vaccine products combined against hospitalisation for laboratory-confirmed SARS-CoV-2 was 43% (95% CI: 29-54) for complete PSV (with last dose received ≥ 150 days before onset), while it was 59% (95% CI: 51-66) after addition of one booster dose. The VE was 85% (95% CI: 78-89), 70% (95% CI: 61-77) and 36% (95% CI: 17-51) for those with onset 14-59 days, 60-119 days and 120-179 days after booster vaccination, respectively.ConclusionsOur results suggest that, during the Omicron period, observed VE against SARI hospitalisation improved with first mRNA booster dose, particularly for those having symptom onset < 120 days after first booster dose.

Vaccine effectiveness against COVID-19 hospitalisation in adults (≥ 20 years) during Alpha- and Delta-dominant circulation: I-MOVE-COVID-19 and VEBIS SARI VE networks, Europe, 2021

IntroductionTwo large multicentre European hospital networks have estimated vaccine effectiveness (VE) against COVID-19 since 2021.AimWe aimed to measure VE against PCR-confirmed SARS-CoV-2 in hospitalised severe acute respiratory illness (SARI) patients ≥ 20 years, combining data from these networks during Alpha (March-June)- and Delta (June-December)-dominant periods, 2021.MethodsForty-six participating hospitals across 14 countries follow a similar generic protocol using the test-negative case-control design. We defined complete primary series vaccination (PSV) as two doses of a two-dose or one of a single-dose vaccine ≥ 14 days before onset.ResultsWe included 1,087 cases (538 controls) and 1,669 cases (1,442 controls) in the Alpha- and Delta-dominant periods, respectively. During the Alpha period, VE against hospitalisation with SARS-CoV2 for complete Comirnaty PSV was 85% (95% CI: 69-92) overall and 75% (95% CI: 42-90) in those aged ≥ 80 years. During the Delta period, among SARI patients ≥ 20 years with symptom onset ≥ 150 days from last PSV dose, VE for complete Comirnaty PSV was 54% (95% CI: 18-74). Among those receiving Comirnaty PSV and mRNA booster (any product) ≥ 150 days after last PSV dose, VE was 91% (95% CI: 57-98). In time-since-vaccination analysis, complete all-product PSV VE was > 90% in those with their last dose < 90 days before onset; ≥ 70% in those 90-179 days before onset.ConclusionsOur results from this EU multi-country hospital setting showed that VE for complete PSV alone was higher in the Alpha- than the Delta-dominant period, and addition of a first booster dose during the latter period increased VE to over 90%.

Monitoring COVID-19 vaccine effectiveness against COVID-19 hospitalisation and death using electronic health registries in ≥65 years old population in six European countries, October 2021 to November 2022

BACKGROUND

Within the ECDC-VEBIS project, we prospectively monitored vaccine effectiveness (VE) against COVID-19 hospitalisation and COVID-19-related death using electronic health registries (EHR), between October 2021 and November 2022, in community-dwelling residents aged 65-79 and ≥80 years in six European countries.

METHODS

EHR linkage was used to construct population cohorts in Belgium, Denmark, Luxembourg, Navarre (Spain), Norway and Portugal. Using a common protocol, for each outcome, VE was estimated monthly over 8-week follow-up periods, allowing 1 month-lag for data consolidation. Cox proportional-hazards models were used to estimate adjusted hazard ratios (aHR) and VE = (1 - aHR) × 100%. Site-specific estimates were pooled using random-effects meta-analysis.

RESULTS

For ≥80 years, considering unvaccinated as the reference, VE against COVID-19 hospitalisation decreased from 66.9% (95% CI: 60.1; 72.6) to 36.1% (95% CI: -27.3; 67.9) for the primary vaccination and from 95.6% (95% CI: 88.0; 98.4) to 67.7% (95% CI: 45.9; 80.8) for the first booster. Similar trends were observed for 65-79 years. The second booster VE against hospitalisation ranged between 82.0% (95% CI: 75.9; 87.0) and 83.9% (95% CI: 77.7; 88.4) for the ≥80 years and between 39.3% (95% CI: -3.9; 64.5) and 80.6% (95% CI: 67.2; 88.5) for 65-79 years. The first booster VE against COVID-19-related death declined over time for both age groups, while the second booster VE against death remained above 80% for the ≥80 years.

CONCLUSIONS

Successive vaccine boosters played a relevant role in maintaining protection against COVID-19 hospitalisation and death, in the context of decreasing VE over time. Multicountry data from EHR facilitate robust near-real-time VE monitoring in the EU/EEA and support public health decision-making.

Impact of Lifting Mask Mandates on COVID-19 Incidence and Mortality in Portugal: An Ecological Study

INTRODUCTION

The use of face masks in public was one of several COVID-19 non-pharmaceutical interventions adopted to mitigate the pandemic in Portugal. The aim of this study was to evaluate the impact of lifting the mask mandate on the April 22, 2022 on COVID-19 incidence and mortality in mainland Portugal and in the Azores. As a secondary objective, we aimed to evaluate the evolution of COVID-19 cases in a setting without a mask mandate (Azores islands) and in a setting with a mask mandate (Madeira islands).

MATERIAL AND METHODS

Surveillance data on laboratory-confirmed COVID-19 cases and COVID-19 deaths were used to conduct an interrupted time series analysis to estimate changes in daily incidence and deaths during a mask mandate period (28th March - 21st April 2022) and during a post-mask mandate period (22nd April - 15th May 2022), in mainland Portugal and the Azores. In a second phase, for each group of islands, we fitted a negative binomial regression model, with daily COVID-19 incident cases as the primary outcome of interest, and relative frequency of Omicron BA.5 lineage as explanatory variable.

RESULTS

Significant changes in trends were observed for the overall incidence rate and COVID-19 deaths; increasing trends were observed for COVID-19 incidence and deaths in the post mandate period [5.3% per day; incidence rate ratio (IRR): 1.053; 95% confidence interval (CI): 1.029 - 1.078] and [3.2% per day; mortality rate ratio (MRR): 1.032; 95% CI: 1.003 - 1.062], respectively. For every unit increase in the percentage of Omicron BA.5 lineage there was a 1.5% increase per day (IRR: 1.015; 95% CI: 1.006 - 1.024) in COVID-19 incidence rate in the Azores islands, while for Madeira islands an increase of 0.05% COVID-19 cases per day was observed (IRR: 1.005; 95% CI: 1.000 - 1.010).

CONCLUSION

Lifting the mask mandate in Portugal was associated with an increase in COVID-19 incidence and deaths, thus highlighting the positive effect of face mask policies in preventing respiratory virus transmission and saving lives.

Prevalence Rate of Thalassemia Carriers among Individuals with Microcytosis or Hypochromia in Portugal

INTRODUCTION

Microcytosis and hypochromia result from deficient hemoglobin synthesis in red blood cells and are easily detected in a complete blood count test. These conditions are mainly due to iron nutritional deficiency, but may also result from some genetic diseases, such as thalassemia. The aim of this study was to determine the contribution of β- and α-thalassemia to these abnormal hematological phenotypes in a representative sample of adult individuals living in Portugal who participated in the first Portuguese National Health Examination Survey (INSEF).

MATERIAL AND METHODS

Among the 4808 INSEF participants, 204 had microcytosis, hypochromia or both. The corresponding 204 DNAs were screened for changes in the β-globin gene by next-generation sequencing and Sanger sequencing. In addition, α-thalassemia deletions within the α-globin cluster were investigated by Gap-PCR and multiplex ligation-dependent probe amplification.

RESULTS

In this selected subgroup of INSEF participants, 54 had α-thalassemia (26%), predominantly caused by the -α3.7kb deletion, and 22 were β-thalassemia carriers (11%) mainly due to point mutations in the β-globin gene previously known in Portugal.

CONCLUSION

Thalassemia trait is a frequent cause of microcytosis or hypochromia in Portugal since this genetic condition was found in 37% of the investigated cases.

COVID-19 vaccine effectiveness among healthcare workers: a hospital-based cohort study

OBJECTIVES

Healthcare workers (HCWs) were the first to be prioritised for COVID-19 vaccination. This study aims to estimate the COVID-19 vaccine effectiveness (VE) against SARS-CoV-2 symptomatic infection among HCWs in Portuguese hospitals.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

We analysed data from HCWs (all professional categories) from three central hospitals: one in the Lisbon and Tagus Valley region and two in the central region of mainland Portugal, between December 2020 and March 2022. VE against symptomatic SARS-CoV-2 infection was estimated as one minus the confounder adjusted HRs by Cox models considering age group, sex, self-reported chronic disease and occupational exposure to patients diagnosed with COVID-19 as adjustment variables.

RESULTS

During the 15 months of follow-up, the 3034 HCWs contributed a total of 3054 person-years at risk, and 581 SARS-CoV-2 events occurred. Most participants were already vaccinated with a booster dose (n=2653, 87%), some are vaccinated with only the primary scheme (n=369, 12.6%) and a few remained unvaccinated (n=12, 0.4%) at the end of the study period. VE against symptomatic infection was 63.6% (95% CI 22.6% to 82.9%) for HCWs vaccinated with two doses and 55.9% (95% CI -1.3% to 80.8%) for HCWs vaccinated with one booster dose. Point estimate VE was higher for individuals with two doses taken between 14 days and 98 days (VE=71.9%; 95% CI 32.3% to 88.3%).

CONCLUSION

This cohort study found a high COVID-19 VE against symptomatic SARS-CoV-2 infection in Portuguese HCWs after vaccination with one booster dose, even after Omicron variant occurrence. The small sample size, the high vaccine coverage, the very low number of unvaccinated individuals and the few events observed during the study period contributed to the low precision of the estimates.

Comparative complete scheme and booster effectiveness of COVID-19 vaccines in preventing SARS-CoV-2 infections with SARS-CoV-2 Omicron (BA.1) and Delta (B.1.617.2) variants: A case-case study based on electronic health records

Background

Information on vaccine effectiveness in a context of novel variants of concern (VOC) emergence is of key importance to inform public health policies. This study aimed to estimate a measure of comparative vaccine effectiveness between Omicron (BA.1) and Delta (B.1.617.2 and sub-lineages) VOC according to vaccination exposure (primary or booster).

Methods

We developed a case-case study using data on RT-PCR SARS-CoV-2-positive cases notified in Portugal during Weeks 49-51, 2021. To obtain measure of comparative vaccine effectiveness, we compared the odds of vaccination in Omicron cases versus Delta using logistic regression adjusted for age group, sex, region, week of diagnosis, and laboratory of origin.

Results

Higher odds of vaccination were observed in cases infected by Omicron VOC compared with Delta VOC cases for both complete primary vaccination (odds ratio [OR] = 2.1; 95% confidence interval [CI]: 1.8 to 2.4) and booster dose (OR = 5.2; 95% CI: 3.1 to 8.8), equivalent to reduction of vaccine effectiveness from 44.7% and 92.8%, observed against infection with Delta, to -6.0% (95% CI: 29.2% to 12.7%) and 62.7% (95% CI: 35.7% to 77.9%), observed against infection with Omicron, for complete primary vaccination and booster dose, respectively.

Conclusion

Consistent reduction in vaccine-induced protection against infection with Omicron was observed. Complete primary vaccination may not be protective against SARS-CoV-2 infection in regions where Omicron variant is dominant.

Comparative Effectiveness of COVID-19 Vaccines in Preventing Infections and Disease Progression from SARS-CoV-2 Omicron BA.5 and BA.2, Portugal

We estimated comparative primary and booster vaccine effectiveness (VE) of SARS-CoV-2 Omicron BA.5 and BA.2 lineages against infection and disease progression. During April-June 2022, we implemented a case-case and cohort study and classified lineages using whole-genome sequencing or spike gene target failure. For the case-case study, we estimated the adjusted odds ratios (aORs) of vaccination using a logistic regression. For the cohort study, we estimated VE against disease progression using a penalized logistic regression. We observed no reduced VE for primary (aOR 1.07 [95% CI 0.93-1.23]) or booster (aOR 0.96 [95% CI 0.84-1.09]) vaccination against BA.5 infection. Among BA.5 case-patients, booster VE against progression to hospitalization was lower than that among BA.2 case-patients (VE 77% [95% CI 49%-90%] vs. VE 93% [95% CI 86%-97%]). Although booster vaccination is less effective against BA.5 than against BA.2, it offers substantial protection against progression from BA.5 infection to severe disease.

Seroprevalence of Specific SARS-CoV-2 Antibodies during Omicron BA.5 Wave, Portugal, April-June 2022

After the rapid spread of SARS-CoV-2 BA.5 Omicron lineage in Portugal, we developed a seroepidemiologic survey based on a sample of 3,825 residents. Results indicated that from April 27 through June 8, 2022, the estimated seroprevalence of SARS-CoV-2 nucleocapsid or spike IgG was 95.8%, which indicates a high level of protection.

SARS-CoV-2 Seroprevalence Following a Large-Scale Vaccination Campaign in Portugal: Results of the National Serological Survey, September - November 2021

INTRODUCTION

Following a COVID-19 mass vaccination campaign, it is important to evaluate the population level of SARS-CoV-2 antibodies. The aim of this study was to estimate the seroprevalence rate of SARS-CoV-2 specific antibodies acquired due to infection or vaccination in the Portuguese population.

MATERIAL AND METHODS

The National Serological Survey (third wave - ISN3COVID-19) is a cross-sectional nationwide epidemiological study developed on a sample of 4545 Portuguese residents aged one year or older, between the 28th September 2021 and the 19th November 2021. The SARS-CoV-2 anti-nucleoprotein and anti-spike IgG antibody levels were determined in serum samples using Abbott Chemiluminescent Microparticle Immunoassays. Seroprevalence estimates were stratified by age group, sex, administrative region and self-reported chronic conditions. Medians and respective 95% confidence intervals were used to describe the distribution of SARS-CoV-2 specific antibodies in specific population subgroups.

RESULTS

The total seroprevalence rate of SARS-CoV-2 was 86.4% (95% CI: 85.2% to 87.6%). A higher seroprevalence rate was estimated for women (88.3%), 50 to 59 years-old (96.5%) and in those with two or more self-reported chronic conditions (90.8%). A higher IgG (anti-Spike) concentration was observed in individuals vaccinated with the booster dose (median = 1 2601.3 AU/mL; 95% CI: 4127.5 to 19 089.1).

CONCLUSION

There was a significant increase in SARS-CoV-2 seroprevalence following the mass vaccination campaign in Portugal. It is important to continue to monitor the distribution of specific SARS-COV-2 antibody at the population level to further inform public health policies.

Case-case study on comparative vaccine effectiveness against Delta and Omicron SARS-CoV-2 infections

Introduction

Vaccination is the primary pharmacological measure to reduce SARS-CoV-2 transmission and its complications. Timely information on vaccines effectiveness in a context of novel variants of concern (VOC) emergence is essential for public health policies. This study aimed to provide a measure of comparative vaccine effectiveness between Omicron (BA.1) and Delta (B.1.627.2) VOC according to vaccination exposure (complete primary regimen or booster dose) for Portuguese population aged 12 or more years old using routinely collected data from electronic health records.

Methods

We used a case-case study design linking national electronic vaccination registry and surveillance data on 13,134 SARS-CoV-2 RT-PCR laboratory-confirmed cases notified in Portugal during weeks 49-51 of 2021. Notified cases were classified as Omicron or Delta based on whole-genome sequencing or S-gene Target Failure (SGTF) status using the RT-PCR TaqPath™ Covid 19 CE IVD Kit (Thermo Scientific™) assay. The odds of vaccination was compared between Omicron cases and Delta cases using logistic regression adjusted for age group, sex, region and week of diagnosis and laboratory of origin.

Results

The odds of vaccination were higher in laboratory-confirmed cases infected by Omicron (BA.1) VOC compared to Delta (B.1.627.2) VOC for both complete primary vaccination (Odds ratio (OR)=2.1; 95% Confidence Interval (95%CI): 1.8 - 2.4) and booster dose (OR = 5.2; 95%CI: 3.1 - 8.8), indicating vaccine effectiveness reduction against Omicron.

Conclusions

We found significantly higher odds of vaccination in Omicron cases compared to Delta, suggesting lower effectiveness of the primary vaccination and the booster dose in preventing infections by Omicron. Case-case study design has proven to be feasible approach to rapidly compare vaccine effectiveness between VOC in context of novel VOC emergence to timely inform public health stakeholders.

Key messages

• Reduction of vaccine-induced protection against SARS-COV-2 infection with the Omicron compared to Delta after primary and booster vaccination.

• Continuous monitoring of COVID-19 vaccine effectiveness is essential to support public health policies in context of novel VOC emergence.

Impact of booster vaccination on COVID-19 outcomes in Portuguese population aged 80 or more years old

Background

Vaccination is essential to control SARS-CoV-2 transmission and complications. The study aimed to estimate the number of SARS-CoV-2 infections, COVID-19 hospitalizations and deaths averted by booster vaccination in Portuguese population aged 80 or more years old.

Methods

We developed an ecological study for the period of the Omicron variant of concern predominance (week 2 to week 16, 2022). Data on vaccine coverage and effectiveness, and number of events of different severity reported to the national COVID-19 surveillance system were used to estimate the number of averted events, prevented fraction and number needed to vaccinate. Uncertainty intervals (UI) were obtained using Monte Carlo simulations.

Results

By week 2 2022, vaccination coverage in the target population reached 91.2%. Booster vaccine effectiveness was 4.1% (CI95%: -0.1 to 9.0), 87.5% (CI95%: 84.9 to 89.7) and 83.2 (CI95%: 80.3 to 85.7) against infection, hospitalization and death, respectively. During the study period, 70862 SARS-CoV-2 infections, 2697 COVID-19 hospitalizations and 2106 deaths were reported. Booster vaccination averted 2731 (UI95%: -298 to 5838) infections, 10629 (UI95%: 9173 to 12127) hospitalizations and 6608 (UI95%: 5725 to 7546) COVID-19 related deaths among individuals aged 80 years or more resident in Portugal. Prevented fractions were 3.7% (UI95%: 0 to 7.6%), 79.7% (UI95%: 77.3 to 81.7%) and 75.8% (UI95%: 73.2 to 78.1%), respectively. It would require to vaccinate 59 individuals (UI95%: 52 to 69) to prevent one hospitalization and 94 individuals (UI95%: 82 to 109) to prevent one death in the target population.

Conclusions

The booster vaccination strategy had considerable impact on preventing severe outcomes in the Portuguese population aged 80 and more years old.

Key messages

• High vaccine coverage combined with high vaccine effectiveness resulted in considerable reduction of severe COVID-19 outcomes.

• Information on number of outcomes of different severity levels averted by COVID-19 booster vaccination allows to strength public health communication.

Seroprevalence and SARS-CoV-2 antibodies distribution in Portugal following mass vaccination campaign

Introduction

Information on post-infection and vaccine-induced SARS-CoV-2 seroprevalence is important for public health policies. A 3rd wave of National Serological Survey (ISN3COVID-19) was conducted to measure SARS-CoV-2 seroprevalence and characterize specific antibodies distribution in Portuguese population in September - November 2021, following a mass vaccination campaign.

Methods

ISN3COVID-19 was a cross-sectional epidemiological study that collected serum samples and questionnaire data on a sample of Portuguese residents aged 1 year or older (n = 4545). SARS-CoV-2 IgG anti-nucleoprotein and anti-spike antibody levels were measured using Abbott Chemiluminescent Microparticle Immunoassays. Seroprevalence was estimated for the overall sample and stratified by age group, sex, region and self-reported chronic conditions. Medians and respective 95% confidence intervals (95%CI) were used to describe the distribution of SARS-CoV-2 antibodies in specific population subgroups.

Results

The overall seroprevalence of SARS-CoV-2 (post-infection or vaccine-induced) was 86.4% (95%CI: 85.2 to 87.6%), post-infection seroprevalence was 7.5% (95%CI: 6.6 to 8.5). Higher seroprevalence was observed among 50-59 years-old (96.5%), women (88.3%), and those with two or more self-reported chronic conditions (90.8%). Higher IgG (anti-Spike) levels were estimated for individuals vaccinated with the booster dose (median=12601.3 AU/ml; 95%CI: 4127.5 to 19089.1) and for those vaccinated with two doses of Spikevax® vaccine (median=7012.7 AU/ml, 95%CI: 5568.8 to 8456.6).

Conclusions

The SARS-CoV-2 seroprevalence was high and consistent with vaccine coverage in Portugal. Seropositivity was associated with sex, age and previous chronic conditions. The anti-SARS-CoV-2 anti-spike IgG levels varied according to vaccine brand and number of doses. These results show that monitoring seroprevalence and SARS-CoV-2 antibody distribution is of paramount importance to guide public health policies.

Key messages

• Significant increase in SARS-CoV-2 seroprevalence following the mass vaccination campaign consistent with the high vaccine coverage achieved in Portugal.

• Continuous monitoring of the population‐level IgG response after vaccination remains important to guide further public health measures.

COVID-19 mRNA vaccine effectiveness (second and first booster dose) against hospitalisation and death during Omicron BA.5 circulation: cohort study based on electronic health records, Portugal, May to July 2022

We measured vaccine effectiveness (VE) against COVID-19-related severe outcomes in elderly people in Portugal between May and July 2022. In ≥ 80 year-olds, the second booster dose VE was 81% (95% CI: 75–85) and 82% (95% CI: 77–85), respectively, against COVID-19-related hospitalisation and death. The first booster dose VE was 63% (95% CI: 55–70) in ≥ 80 year-olds and 74% (95% CI: 66–80) in 60–79 year-olds against hospitalisation, and 63% (95% CI: 57–69) and 65% (95% CI: 54–74) against death.

COVID-19 vaccine effectiveness against symptomatic SARS-CoV-2 infections, COVID-19 related hospitalizations and deaths, among individuals aged ≥65 years in Portugal: A cohort study based on data-linkage of national registries February-September 2021

Background

Using data from electronic health registries, this study intended to estimate the COVID-19 vaccine effectiveness (VE) in the population aged 65 years and more, against symptomatic infection, COVID-19-related hospitalizations, and deaths, overall and by time since complete vaccination for the period February to September 2021

Methods

We established a cohort of individuals aged 65 and more years old, resident in Portugal mainland, using the National Health Service User number to link eight electronic health registries. Outcomes included were symptomatic SARS-CoV-2 infections, COVID-19-related hospitalizations or deaths. The exposures of interest were the mRNA vaccines (Comirnaty or Spikevax) and the viral vector (Vaxzevria) vaccine. Complete schedule VE was estimated as one minus the confounder adjusted hazard ratio, for each outcome, estimated by time-dependent Cox regression with time-dependent vaccine exposure.

Results

For the cohort of individuals aged 65–79 years, complete scheme VE against symptomatic infection varied 43 (95%CI: 37–49) (Vaxzevria) and 65 (95%CI: 62–68) (mRNA vaccines). This estimate was slightly lower in the ≥80 years cohort (53, 95%CI: 45–60) for mRNA vaccines). VE against COVID-19 hospitalization varied between 89% (95%CI: 52–94) for Vaxzevria and 95% (95%CI: 93–97) for mRNA vaccines for the cohort aged 65–79 years and was 76% (95%CI: 67–83) for mRNA vaccines in the ≥80 years cohort. High VE against COVID-19-related deaths was estimated, for both vaccine types, 95% and 81 (95%CI:76–86) for the 65–79 years and the ≥80 years cohort, respectively. We observed a significant waning of VE against symptomatic infection, with VE estimates reaching approximately 34% for both vaccine types and cohorts. Significant waning was observed for the COVID-19 hospitalizations in the ≥80 years cohort (decay from 83% (95%CI:68 to 91) 14–41 days to 63% (95%CI:37 to 78) 124 days after mRNA second dose). No significant waning effect was observed for COVID-19-related deaths in the period of follow-up of either cohort.

Conclusions

In a population with a high risk of SARS-CoV-2 complications, we observed higher overall VE estimates against more severe outcomes for both age cohorts when compared to symptomatic infections. Considering the analysis of VE according to time since complete vaccination, the results showed a waning effect for both age cohorts in symptomatic infection and COVID-19 hospitalization for the 80 and more years cohort.

Local problem solving in the Portuguese health examination survey: a mixed method study

Background

Participation rates in health surveys, recognized as an important quality dimension, have been declining over the years, which may affect representativeness and confidence in results. The Portuguese national health examination survey INSEF (2015) achieved a participation rate of 43.9%, which is in line with participation rates from other similar health examination surveys. The objective of this article is to describe how local teams of survey personnel conducted the survey, describing strategies used to solve practical survey problems and to try to increase the participation rate.

Methods

After a literature search, informal interviews were conducted with 14 public health officials from local health examination teams, regional and central authorities. Forty-one of the local staff members (survey personnel) also filled in a short questionnaire anonymously. The interviews and self-administered questionnaires were analysed using mixed methods, informed by thematic analysis.

Results

The local teams believed that the detailed manual, described as a “cookbook for making a health examination survey”, made it possible to maintain high scientific standards while allowing for improvising solutions to problems in the local context. The quality of the manual, supported by a series of training workshops with the central research and support team, gave the teams the confidence and knowledge to implement local solutions. Motivation and cohesion within the local teams were among the goals of the training process.

Local teams felt empowered by being given large responsibilities and worked hard to incite people to attend the examination through a close and persuasive approach.

Local teams praised their INSA contacts for being available for assistance throughout the survey, and said they were inspired to try harder to reach participants to please their contacts for interpersonal reasons.

Conclusions

The theory of organizational improvisation or bricolage, which means using limited resources to solve problems, was useful to discuss and understand what took place during INSEF.

A detailed manual covering standard procedures, continuous monitoring of the data collection and face-to-face workshops, including role-play, were vital to assure high scientific standards and high participation rates in this health examination survey. Close contacts between the central team and local focal points in all regions and all survey sites were key to accommodating unexpected challenges and innovative solutions.

Estimation of COVID-19 vaccine effectiveness against hospitalisation in individuals aged ≥ 65 years using electronic health registries; a pilot study in four EU/EEA countries, October 2021 to March 2022

By employing a common protocol and data from electronic health registries in Denmark, Navarre (Spain), Norway and Portugal, we estimated vaccine effectiveness (VE) against hospitalisation due to COVID-19 in individuals aged ≥ 65 years old, without previous documented infection, between October 2021 and March 2022. VE was higher in 65-79-year-olds compared with ≥ 80-year-olds and in those who received a booster compared with those who were primary vaccinated. VE remained high (ca 80%) between ≥ 12 and < 24 weeks after the first booster administration, and after Omicron became dominant.

Impact of stringent non-pharmaceutical interventions applied during the second and third COVID-19 epidemic waves in Portugal, 9 November 2020 to 10 February 2021: an ecological study

Background

Non-pharmaceutical interventions (NPIs) were implemented worldwide to control the spread of SARS-CoV-2.

Aim

To evaluate the impact of tiered NPIs and a nationwide lockdown on reduction of COVID-19 incidence during the second and third epidemic waves in Portugal.

Methods

Surveillance data on laboratory-confirmed COVID-19 cases were used to conduct an interrupted time series analysis to estimate changes in daily incidence during a second wave tiered NPI period (9 November–18 December 2020), and a third wave lockdown period without (15–21 January 2021) and with school closure (22 January–10 February 2021).

Results

Significant changes in trends were observed for the overall incidence rate; declining trends were observed for tiered NPIs (−1.9% per day; incidence rate ratio (IRR): 0.981; 95% confidence interval (CI): 0.973–0.989) and a lockdown period without (−3.4% per day; IRR: 0.966; 95% CI: 0.935–0.998) and with school closure (−10.3% per day, IRR: 0.897; 95% CI: 0.846–0.951). Absolute effects associated with tiered NPIs and a lockdown on a subsequent 14-day period yielded 137 cases and 437 cases per 100,000 population potentially averted, respectively.

Conclusion

Our results indicate that tiered NPIs implemented during the second wave caused a decline in COVID-19 incidence, although modest. Moreover, a third wave lockdown without school closure was effective in reducing COVID-19 incidence, but the addition of school closure provided the strongest effect. These findings emphasise the importance of early and assertive decision-making to control the pandemic.

Comparative Effectiveness of Coronavirus Vaccine in Preventing Breakthrough Infections among Vaccinated Persons Infected with Delta and Alpha Variants

We developed a case-case study to compare mRNA vaccine effectiveness against Delta versus Alpha coronavirus variants. We used data on 2,097 case-patients with PCR-positive severe acute respiratory syndrome coronavirus 2 infections reported in Portugal during May-July 2021. We estimated the odds of vaccine breakthrough infection in Delta-infected versus Alpha-infected patients by using conditional logistic regression adjusted for age group and sex and matched by the week of diagnosis. We compared reverse-transcription PCR cycle threshold values by vaccination status and variant as an indirect measure of viral load. We found significantly higher odds of vaccine breakthrough infection in Delta-infected patients than in Alpha-infected patients (odds ratio 1.96 [95% CI 1.22-3.14]), suggesting lower effectiveness of the mRNA vaccines in preventing infection with the Delta variant. We estimated lower mean cycle threshold values for the Delta cases (mean difference -2.10 [95% CI -2.74 to -1.47]), suggesting higher infectiousness than the Alpha variant.

SARS-CoV-2 seroprevalence in Portugal following the third epidemic wave: results of the second National Serological Survey (ISN2COVID-19)

BACKGROUND

Integrated approaches to surveillance of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection are important for public health actions. The 2nd National Serological Survey (ISN2COVID-19) aimed to characterize the extent of SARS-CoV-2 infection and vaccine-induced response in the Portuguese population following the third epidemic wave and the launch of the vaccination campaign.

METHODS

A cross-sectional study was performed using data on 8463 Portuguese 1-79 years of age, collected in February and March, 2021. SARS-CoV-2 IgM and IgG (anti-nucleoprotein and anti-spike) antibodies were determined in serum samples using Abbott Architect chemiluminescent microparticle assays. Post-infection and vaccine-induced seroprevalence with 95% confidence intervals (95%CI) were estimated in the overall sample and stratified by population characteristics.

RESULTS

The estimated seroprevalence was 15.5% (95%CI:14.6-16.5%), of which 13.5% (95%CI: 12.6-14.4%) was attributable to natural infection and 2.0% (95%CI:1.7-2.4%) to vaccination. The lowest seroprevelence was observed in persons aged 70-79 years (8.9% 95%CI:6.8-11.6), while seroprevalence in children (14.3%; 95%CI:11.5-17.6%) and adolescents (12.9%; 95%CI:10.5-15.7%) was similar to that of persons aged between 20 and 69 years. Of seropositive individuals, 22.6% (95%CI:19.7-25.9%) did not report any symptoms in 6 months prior to interview. Of persons with completed vaccination (2-doses), 98.6% (95%CI: 93.0-99.7%) had specific IgG (anti-S) antibodies.

CONCLUSIONS

After the third epidemic wave, the post-infection SARS-CoV-2 seroprevalence was 1.7 times higher than the cumulative incidence based on PCR-testing, but was higher (2.7 times) in children may be due to the high proportion of asymptomatic and mild infections.

[Metabolic Syndrome in Portugal: Prevalence and Associated Factors]

INTRODUCTION

The metabolic syndrome consists of a set of factors that, when associated, are associated with a higher risk of developing cardiovascular diseases and type 2 diabetes, and is thus an important public health problem. The objective of this study was to estimate the prevalence of this syndrome in the Portuguese population, and to evaluate possible associations with demographic and socioeconomic determinants.

MATERIAL AND METHODS

Based on the 1st National Health Survey with Physical Examination of 2015, a cross-sectional epidemiological study was conducted on a representative sample of the Portuguese population (n = 4797) aged between 25 and 74 years old. The prevalence was estimated for the total population and each gender, stratified by age group, health region, type of urban area, marital status, education, professional status, and risk of poverty. The magnitude of the associations was measured with adjusted prevalence ratios.

RESULTS

In the Portuguese population the estimated prevalence was 33.4% [95% CI, 31.7 - 35.1] [35.6% in men (95% CI, 31.9 - 39.2) and 31.3% in women (95% CI, 28.5 - 34.2)]. In both genders, the highest prevalence was significantly associated with increasing age, widowed/married/de facto partners and those with lower levels of education. There was no association with gender, health region, type of urban area, professional status or risk of poverty.

DISCUSSION

This syndrome was present in a third of the Portuguese population. The knowledge of its epidemiology enables the identification of population groups with higher cardiovascular and metabolic risk.

CONCLUSION

Metabolic syndrome was independently associated with specific groups. This knowledge reinforces the importance of a holistic assessment of the health determinants associated with the metabolic syndrome.

mRNA vaccine effectiveness against COVID-19-related hospitalisations and deaths in older adults: a cohort study based on data linkage of national health registries in Portugal, February to August 2021

Through deterministic data linkage of health registries, mRNA vaccine effectiveness (VE) against COVID-19-related hospitalisations and deaths was measured in 1,880,351 older adults. VE against hospitalisations was 94% (95% confidence interval (CI): 88–97) and 82% (95% CI: 72–89) for those 65–79 and ≥ 80 years old, with no evidence of waning 98 days after dose two. VE against mortality was 96% (95% CI: 92–98) and 81% (95% CI: 74–87) in these two age groups.

Vaccine effectiveness against symptomatic SARS-CoV-2 infection in adults aged 65 years and older in primary care: I-MOVE-COVID-19 project, Europe, December 2020 to May 2021

We measured COVID-19 vaccine effectiveness (VE) against symptomatic SARS-CoV-2 infection at primary care/outpatient level among adults ≥ 65 years old using a multicentre test-negative design in eight European countries. We included 592 SARS-CoV-2 cases and 4,372 test-negative controls in the main analysis. The VE was 62% (95% CI: 45–74) for one dose only and 89% (95% CI: 79–94) for complete vaccination. COVID-19 vaccines provide good protection against COVID-19 presentation at primary care/outpatient level, particularly among fully vaccinated individuals.

Factors Associated with the Use of Fecal Immunochemical Tests and Colonoscopy in the INSEF Portuguese Population

<b><i>Introduction:</i></b> The incidence of colorectal cancer is increasing worldwide. However, the screening uptake is generally low. We analyzed the association between sociodemographic, economic, and access-to-healthcare factors and the use of exams that are the basis for colorectal cancer screening in Portugal. <b><i>Methods:</i></b> We conducted a cross-sectional study based on data from the 1st National Health Examination Survey. We used Poisson regression to estimate prevalence ratios and study factors associated with the use of fecal immunochemical tests (FIT) and colonoscopy in a Portuguese population aged 50–74 years (<i>n</i> = 2,489). <b><i>Results:</i></b> 45.7% of the individuals reported using FIT in the previous 2 years; 37.3% reported using colonoscopy in the previous 5 years. The use of FIT was associated with age group, health region, and having a family doctor. It was higher in older individuals (47.6% in the age group 70–74 years vs. 38.1% in the age group 50–54 years; adjusted prevalence ratio [aPR] = 1.32; 95% CI 1.05–1.65), and in individuals assigned to a family doctor (47.6 vs. 30.3%; aPR = 1.50; 95% CI 1.14–1.98). Colonoscopy was associated with age group, health region, higher education, economic capacity, and having a family doctor. It was higher in older individuals (45.3% in the age group 70–74 years vs. 25.6% in the age group 50–54 years; aPR = 1.85; 95% CI 1.42–2.40), individuals with a higher economic capacity (40.5 vs. 32.4%; aPR = 1.19; 95% CI 1.01–1.40), and individuals assigned to a family doctor (38.7 vs. 25.6%; aPR = 1.43; 95% CI 1.08–1.91). <b><i>Discussion/Conclusion:</i></b> In our analysis, the use of FIT and colonoscopy was influenced by sociodemographic, economic, and access-to-healthcare factors. This is relevant to guide interventions in this area. It is essential to ensure an equitable and uniform implementation of the screening program, with family doctors as an important part of the process.

No effect modification of influenza virus vaccine effectiveness by age or chronic condition was observed in the 2010/11 to 2017/18 seasons

PURPOSE

Most European influenza vaccine strategies target individuals at higher risk of complications, which include, among others, individuals aged ≥65 years and with chronic conditions. These individuals not only have a high-risk of post-infection complications but also could have lower capacity of acquiring adequate vaccine-induced protection. As such, chronic conditions and age could modify the effect of vaccines. This study aimed at assessing the potential effect modification of influenza vaccine effectiveness (IVE) by age and chronic conditions.

METHODS

We used eight-season data from the Portuguese vaccine effectiveness study. Every season, physicians at primary care units recruited patients with influenza-like illness. Clinical data and swabs were collected for Reverse Transverse Polymerase Chain Reaction (RT-PCR) detection of influenza. Trivalent inactivated IVE was estimated as 1 - odds ratio (OR) of being vaccinated in cases (RT-PCR positive for influenza) versus negative controls. ORs were obtained using a multivariable conditional logistic regression model, paired by week of onset within each season. Confounders were assessed by designing a specific causal diagram. Age (< 65 or ≥65 years) and chronic conditions (diabetes, cardiovascular disease, chronic renal disease, chronic hepatic disease, obesity, chronic respiratory disease, and congenital or acquired immunodeficiency) were studied as effect modifiers by including an interaction term in the regression models. Significance was established at 5%.

RESULTS

Point estimates indicate a higher IVE in the chronic condition strata compared to that in the no chronic condition strata. Regarding age, different results were obtained considering the virus type and (sub)type. When comparing the ≥65 years with the <65 years of age strata, we observed a higher IVE against A(H1N1)pdm09, an equal IVE against A(H3N2) and a lower IVE against B virus. However, all interaction terms were statistically insignificant, and this may be due to a small sample size.

CONCLUSION

The potential effect modification of age or chronic condition was not observed within our study.

Combining self-reported and objectively measured survey data to improve hypertension prevalence estimates: Portuguese experience

BACKGROUND

Accurate data on hypertension is essential to inform decision-making. Hypertension prevalence may be underestimated by population-based surveys due to misclassification of health status by participants. Therefore, adjustment for misclassification bias is required when relying on self-reports. This study aims to quantify misclassification bias in self-reported hypertension prevalence and prevalence ratios in the Portuguese component of the European Health Interview Survey (INS2014), and illustrate application of multiple imputation (MIME) for bias correction using measured high blood pressure data from the first Portuguese health examination survey (INSEF).

METHODS

We assumed that objectively measured hypertension status was missing for INS2014 participants (n = 13,937) and imputed it using INSEF (n = 4910) as auxiliary data. Self-reported, objectively measured and MIME-corrected hypertension prevalence and prevalence ratios (PR) by sex, age group and education were estimated. Bias in self-reported and MIME-corrected estimates were computed using objectively measured INSEF data as a gold-standard.

RESULTS

Self-reported INS2014 data underestimated hypertension prevalence in all population subgroups, with misclassification bias ranging from 5.2 to 18.6 percentage points (pp). After MIME-correction, prevalence estimates increased and became closer to objectively measured ones, with bias reduction to 0 pp - 5.7 pp. Compared to objectively measured INSEF, self-reported INS2014 data considerably underestimated prevalence ratio by sex (PR = 0.8, 95CI = [0.7, 0.9] vs. PR = 1.2, 95CI = [1.1, 1.4]). MIME successfully corrected direction of association with sex in bivariate (PR = 1.1, 95CI = [1.0, 1.3]) and multivariate analyses (PR = 1.2, 95CI = [1.0, 1.3]). Misclassification bias in hypertension prevalence ratios by education and age group were less pronounced and did not require correction in multivariate analyses.

CONCLUSIONS

Our results highlight the importance of misclassification bias analysis in self-reported hypertension. Multiple imputation is a feasible approach to adjust for misclassification bias in prevalence estimates and exposure-outcomes associations in survey data.

[Early Detection of COVID-19 in Portugal: Use of Clinical Records]

INTRODUCTION

Syndromic surveillance allows early detection of changes in the population's morbidity pattern. The aim of this study is to evaluate the usefulness of indicators related to access to healthcare services, in COVID-19 surveillance.

MATERIAL AND METHODS

A time series analysis was performed using the weekly incidence rate of COVID-19 in Mainland Portugal, between weeks 14/2020 (March 30 to April 5) and 25/2020 (June 15 to 21), and six indicators: 1) COVID-19 consultations in primary healthcare; 2) number of COVID-19 emergency department visits; 3) number of emergency department visits due to viral pneumonia; 4) number of hospitalizations due to viral pneumonia; 5) proportion of emergency department visits due to viral pneumonia; and 6) proportion of hospitalizations for viral pneumonia. Pearson correlation and cross-correlations were computed.

RESULTS

A strong correlation was found between the weekly incidence rate of COVID-19 and all indicators. [(1) 0.76; (2) 0.82; (3) 0.77; (4) 0.84; (5) 0.86; e (6) 0.90]. Emergency department visits and hospitalizations for viral pneumonia detect variations in the frequency of the disease with a one week lag compared to the incidence rate of COVID-19, in one week. COVID-19 consultations in primary healthcare and emergency department visits trail behind the incidence rate of COVID-19, in one week. The proportion of viral pneumonias in emergency department visits, or hospitalizations, is temporally aligned with the weekly incidence rate of COVID-19.

DISCUSSION

The delay found in the COVID-19 primary healthcare consultations and emergency department visits, may be related to changes in access to healthcare services and clinical coding. Emergency department visits and hospitalizations for viral pneumonia may be useful in the early detection of COVID-19. Viral pneumonia may have been coded as being of unknown origin. Future monitoring of these indicators is necessary to ascertain whether the incidence of COVID-19 is significantly influenced by changes in testing strategies. The indicators described in this study will be an asset for the optimization of testing strategies, allocation of healthcare resources to the communities that are most vulnerable to severe morbidity and assessing vaccination impact. As such, surveillance systems based on clinical data will be a valuable complementary tool to SINAVE.

CONCLUSION

The indicators under analysis could be used regularly, with special attention to viral pneumonias, to detect outbreaks of COVID-19. Information on pneumonia of unknown etiology may be considered in the surveillance of COVID-19.

Seroprevalence of SARS-CoV-2 Infection in Portugal in May-July 2020: Results of the First National Serological Survey (ISNCOVID-19)

INTRODUCTION

The aim of this study was to estimate and describe the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibodies (immunoglobulin M and/or immunoglobulin G) in Portugal in May-July 2020.

MATERIAL AND METHODS

A cross-sectional seroepidemiological survey was developed after the peak of the first epidemic wave on a sample of 2301 Portuguese residents, aged 1 year or older. Survey sample was selected using a two-stage stratified non-probability sampling design (quota sampling). SARS-CoV-2 immunoglobulin M and immunoglobulin G antibodies were measured in serum samples by enzyme-linked immunosorbent assay. Seroprevalence estimates of immunoglobulin M and/or immunoglobulin G and 95% confidence intervals were stratified by sex, age group, health region and education.

RESULTS

Overall, seroprevalence was 2.9% (95% confidence interval: 2.0% - 4.2%). Higher prevalence rates were observed in male (4.1%, 95% confidence interval: 2.6% - 6.6%) and those with secondary education (6.4%, 95% confidence interval: 3.2% - 12.5%). Differences in seroprevalence by age group and region were not statistically significant.

DISCUSSION

The estimated seroprevalence of SARS-CoV-2 was higher than the cumulative incidence reported by the National Surveillance System but far from necessary to reach herd immunity.

CONCLUSION

Our results support limited extent of infection by SARS-CoV-2 in the study population possibly due to early lockdown measures implemented in Portugal and support the need to continue monitoring of SARS-CoV-2 seroprevalence in order to increase our knowledge about the evolution of the epidemic and to estimate the proportion of the susceptible population over time.

Exploring the Correlates to Depression in Elder Abuse Victims: Abusive Experience or Individual Characteristics?

Depression and depressive symptoms have been studied both as risk factors and consequences of elder abuse, even though the most common cross-sectional design of the studies does not allow inferring cause or consequence relationships. This study estimates the proportion of older adults who screened positive for depressive symptoms among those self-reporting elder abuse and examines whether individual characteristics and/or abusive experience aspects are associated with self-reported depressive symptoms. Participants were 510 older adults self-reporting experiences of abuse in family setting enrolled in the cross-sectional victims' survey of the Aging and Violence Study. Depressive symptoms were assessed through the abbreviated version of the Geriatric Depression Scale (GDS-5). Poisson regression was used to determine the prevalence ratio (PR) of screening depressive symptoms according to individual and abusive experience covariates: sex, age group, cohabitation, perceived social support, chronic diseases, functional status, violence type, perpetrator, and number of conducts. Women (PR = 1.18, 95% confidence interval [CI] = [1.04, 1.35]) individuals perceiving low social support level (PR = 1.36, 95% CI = [1.16, 1.60]) and with long-term illness (PR = 1.17, 95% CI = [1.02, 1.33]) were found to be associated with increased risk for screening depressive symptoms. In regard to abusive experience, only the number of abusive conducts increased the PR (PR = 1.07, 95% CI = [1.05, 1.09]). Routine screening for elder abuse should include psychological well-being assessment. Interventions toward risk alleviation for both mental health problems and elder abuse should target women perceiving low social support level and with long-term illness.

Collecting Valid and Reliable Data: Fieldwork Monitoring Strategies in a Health Examination Survey

<b><i>Introduction:</i></b> Health surveys constitute a relevant information source to access the population’s health status. Given that survey errors can significantly influence estimates and invalidate study findings, it is crucial that the fieldwork progress is closely monitored to ensure data quality. The objective of this study was to describe the fieldwork monitoring conducted during the first Portuguese National Health Examination Survey (INSEF) regarding protocol deviations and key performance indicators (KPI). <b><i>Methods:</i></b> Data derived from interviewer observation and from the statistical quality control of selected KPI were used to monitor the four components of the INSEF survey (recruitment, physical examination, blood collection and health questionnaire). Survey KPI included response rate, average time distribution for procedures, distribution of the last digit in a specific measure, proportion of haemolysed blood samples and missing values. <b><i>Results:</i></b> Interviewer observation identified deviations from the established protocols, which were promptly corrected. During fieldwork monitoring through KPI, upon implementation of corrective measures, the participation rate increased 2.5-fold, and a 4.4-fold decrease in non-adherence to standardized survey procedures was observed in the average time distribution for blood pressure measurement. The proportion of measurements with the terminal digit of 0 or 5 decreased to 19.6 and 16.5%, respectively, after the pilot study. The proportion of haemolysed samples was at baseline level, below 2.5%. Missing data issues were minimized by promptly communicating them to the interviewer, who could recontact the participant and fill in the missing information. <b><i>Discussion/Conclusion:</i></b> Although the majority of the deviations from the established protocol occurred during the first weeks of the fieldwork, our results emphasize the importance of continuous monitoring of survey KPI to ensure data quality throughout the survey.

Estimation of the 10-Year Risk of Fatal Cardiovascular Disease in the Portuguese Population: Results from the First Portuguese Health Examination Survey (INSEF 2015)

INTRODUCTION

Cardiovascular disease is the leading cause of morbidity and mortality in Portugal and globally. Cardiovascular risk algorithms, namely the SCORE (Systematic Coronary Risk Evaluation), are recommended in the context of cardiovascular disease prevention. Our aim is to estimate and characterize the cardiovascular risk of the Portuguese population aged between 40 and 65 years old, in 2015, using the SCORE algorithm.

MATERIAL AND METHODS

This study was performed on a subsample of the first Portuguese National Health Examination Survey - INSEF, including all participants between 40 and 65 years old with available data on sex, age, smoking status, total cholesterol and systolic blood pressure (n = 2945). The prevalence of the cardiovascular risk categories were stratified by sex, age group, marital status, educational level, occupational activity, urbanization of living area, region and income.

RESULTS

In 2015, about 5.1% and 11.9% of the Portuguese resident population aged between 40 and 65 years old were, respectively, at high and very high risk of having a fatal CV event in the following 10 years. The highest prevalence of very high cardiovascular risk was found in males, individuals aged 60-65 years old, married or living with someone, without any formal education or just with the 1st cycle of basic education and belonging to the less skilled category of the occupational activity (C category) in comparison with the othercorresponding groups.

DISCUSSION

A previous national study found a similar proportion of the population at high/very high cardiovascular risk (19.5% versus 17.1%). Our study is representative of the adult Portuguese population and adopted the European Health Examination Survey procedures, which are essential for future comparisons with other European countries. Some of the limitations of this study include the possible participation bias and the non-calibration of the SCORE algorithm for the Portuguese population.

CONCLUSION

In 2015, a considerable proportion of the Portuguese population aged between 40 and 65 years old had a high or very high risk of developing a fatal cardiovascular event in the next 10 years. Due to the possible overestimation of the cardiovascular risk already reported in other European countries, it will be important to carry out a follow-up study to validate the adequacy of using the SCORE algorithm in the Portuguese population.

Trends in breastfeeding rates in Portugal: results from five National Health Interview Surveys

Background

The World Health Organization advice breast milk as the perfect food for the newborn starting immediately after birth and exclusively up to at least 6 months of age. However, there are considerable differences in breastfeeding rates between countries related to their policies on breastfeeding promotion and duration of maternity leave. This study aims to describe changes in breastfeeding rates over time in Portugal as a way to inform social policies and public health initiatives on breastfeeding.

Methods

To examine the breastfeeding rates evolution we used data from five National Health Surveys. Breastfeeding was assessed based on information provided by the mothers of children born between 1982 and 2014. Birth cohorts were grouped in block of 3-year period. We estimated 3 and 6-months exclusive breastfeeding rates and 95% confidence intervals. Trends in breastfeeding rates for each outcome were assessed by linear regression weighting each cohort-specific estimate by the inverse of variance in the logit scale.

Results

We analyzed data on 9172 children; sample size by birth cohort ranged from 213 in 2012/14 to 1651 in 1994/96. Proportion of infants ever breastfed during the study period varied between 71.7% and 86.7%. The 3 months exclusive breastfeeding rate increased by 9.5% (CI95%:7.8-11.3%) per 3-year period, from 41.3% (CI95%:38.7-43.9%) in 1982/84 to 62.4% (CI95%:55.7-68.7%) in 2012/14. The 6 months exclusive breastfeeding rate raised up from 23.5% (CI 95%:21.2-25.7%) in 1982/84 to 31.9% (CI95%:26.0-38.5%) in 2012/14, corresponding to 5.6% increase per 3-year period.

Conclusions

This study shows a positive evolution in breastfeeding practices, with an increased in the prevalence of women who reported exclusively breastfeeding until the 3rd and 6th month after birth. Our results may be explained by changes in maternity leave duration. Furthermore, the results emphasize the need for further investment in breastfeeding support services and professionalś training.

Key messages

Positive evolution in breastfeeding practices in Portugal. Maternity leave duration could have a positive role.

Influenza burden estimates in Portugal: seasons 2013/14 to 2018/19

Background

Reliable influenza burden estimates are essential for a true understanding of the influenza epidemics' impact; informed decision-making and effective risk communication. This study aimed to estimate the influenza burden in Portugal in 2013/14 - 2018/19 seasons.

Methods

We estimated seasonal influenza burden, ranging from medically attended influenza cases in primary care to influenza-attributable deaths, using surveillance data. Data were collected for influenza like illness (ILI) epidemic periods, determined by the Moving Epidemic Method. Medically attended influenza cases were estimated by multiplying the number of ILI cases in primary care by the percentage of influenza-positive samples. Hospitalized severe acute respiratory infections (SARI) positive for influenza estimates were computed, multiplying the number of SARI by the percentage of influenza-positive samples. To determine influenza-attributable deaths, a Poisson regression model was used.

Results

The median number of medically attended influenza cases in primary care was 33,668 (325.8 cases per 10,000 population), ranging between 21,393 in 2017/18, [Influenza B and A(H1) co-dominance] and 61,768 in 2014/15 [Influenza B and A(H3) co-dominance]. The median number of SARI positive for influenza was 8,724 (84.4 cases per 10,000 population), ranging between 7,099 in 2013/14 [A(H1) and A(H3) co-dominance], and 9,125 in 2014/15. The median number of influenza-attributable deaths was 3,311 (32.0 cases per 10,000 population), ranging between 96 in 2015/16 [A(H1) dominance], and 5,224 in 2014/15.

Conclusions

Higher mortality, and higher rate of medically attended influenza cases, were found in seasons with A(H3) circulation. Little variability was observed in the number of influenza-positive SARI. The relationship between the number of SARI and the number of deaths requires further investigation. This work highlights the need of health surveillance systems for a better understanding of the influenza impact.

Key messages

Lower burden of influenza is found in seasons with A(H1) co-dominance. Higher burden of influenza is found in seasons with A(H3) circulation. Health surveillance systems are essential to provide data for a better understanding of the epidemiology and extent of seasonal influenza.

Bias correction in self-reported high blood pressure prevalence based on objectively measured data

Background

Reliable and precise estimates of high blood pressure (HBP) prevalence are essential to inform decision-making and policies evaluation. Self-reported HBP may be underestimated by surveys due to misclassification of health status by participants. Misclassification may lead to inaccurate inference. We aimed to assess a feasibility of correcting misclassification bias in self-reported HBP in the Portuguese component of the European Health Interview Survey (INS2014) using data on objective blood pressure measurements from a smaller health examination survey (INSEF).

Methods

We assumed that “true” measured HBP status was missing at random for INS2014 participants (n = 13937). Using a multiple imputation method of logistic regression for monotone missing data patterns, HBP was imputed for INS2014 sample. Auxiliary data on measured HBP from INSEF (n = 4910) was used. Crude and corrected HBP prevalence rates stratified by sex and age group were calculated.

Results

HBP prevalence based on INS2014 increased significantly after multiple imputation correction, from 22.0% [CI95%:20.6-23.5%] to 38.8% [35.4-41.9%] for men and from 26.8% [25.3-28.3%] to 33.0% [30.5-35.4%] for women. Corrected estimates were similar to the objectively measured from INSEF, 39.6% for men and 32.7% for women. Corrected HBP prevalence in INS2014 increased from 4.1% [2.9-5.9%] to 7.9% [4.0-11.8%] in 25-34 years old (yo); from 9.3% [7.8-11.0%] to 17.6% [14.0-21.3%] in 35-44 yo; from 22.5% [20.3-24.8%] to 38.7% [34.2-43.2%] in 45-54 yo; from 39.8% [37.2-42.4%] to 53.8% [49.1-58.5%] in 55-64 yo and from 54.3% [51.5-57.1%] to 67.7% [63.1-72.3%] in 65-74 yo. Corrected rates were similar to the obtained by INSEF (5.7%, 17.0%, 35.8%, 54.8% and 71.3%, respectively).

Conclusions

Our results highlight the importance of bias analysis when using self-reported data on HBP. Multiple imputation is a feasible approach to adjust misclassification bias in health outcomes collected by population surveys.

Key messages

The magnitude and direction of misclassification bias in self-reported health outcomes should be investigated. Multiple imputation is a feasible approach to misclassification bias correction in self-reported survey data.

Neural tube defects: how many cases could have been prevented in Portugal?

Neural tube defects (NTD) occurs when the neural tube does not close properly until the 28th day of foetal life. About 70% of NTD can be prevent if women start folic acid (FA) before pregnancy and until the end of 1st trimester. Portugal has this primary prevention since 1998, however the secondary prevention of NTD with TOPFA is still high (80%). The aim of this study is to describe when FA intake was started and estimate the number of cases that would have be prevented if FA intake started before pregnancy as recommended.

A cross-sectional study using data from the National Registry of Congenital Anomalies between 2004-2017 was performed. The temporal evolution of the beginning of FA intake was analysed with Cochran-Armitage test for proportions. The proportion of preventable cases was estimated considering the 70% prevention fraction and the number of NTD cases registered in RENAC that occurred in pregnancies without the recommended FA supplementation.

On average, 13.8% of all women started FA before pregnancy, 46.2% during 1st trimester and 6.1% did not take folic acid. A statistically significant trend (p &lt; 0.001) was observed in the group that started before pregnancy with increase from 6.8% in 2004 to 17.9% in 2017. The prevalence of NTD was 4.2 cases / 10,000 births, ranging from 2 cases / 10,000 births (2007) to 7 cases / 10,000 births (2014). Between women who had a pregnancy with NTD, 16.8% started FA before pregnancy, 42.2% in the 1st trimester and 9.7% did not take the supplement. If all women had started FA before pregnancy, an estimated 202 NTD cases could have been prevented.

In Portugal, the proportion of women who adhere to this measure is very low, similarly to other European countries, compromising the primary prevention of NTD. Perhaps due to the high percentage of TOPFA, the idea that this anomalies continue to affect our children has been lost. Primary prevention of NTDs should be encouraged with measures that promote FA supplementation.

Key messages

Primary prevention of NTD is possible. Proportion of women who adhere to primary prevention is low.

The number of cancers attributable to tobacco by sex, in mainland Portugal, in 2008

Background

In Portugal, cancer incidence increases annually about 3%. In 2016, cancer was the first cause of premature death, corresponding to 5 296.8 DALYs/100,000 inhabitants. The aim of this study is to estimate the number of cancers attributable to tobacco in mainland's Portugal by sex.

Methods

An observational, ecological, analytic study was performed. Data was collected by sex: tobacco consumption (current or past) in mainland Portugal resident population older than 20 years, in 1998; incidence of 12 types of cancer, by location: Esophagus (C15), Stomach (C16), Colon (C18), Rectum (C20), Liver (C22), Pancreas (C25), Larynx (C32), Lung (C34), Kidney (C64) and Bladder (C67), according to the ICD-10 classification, in 2008. The population attributable fraction (PAF), for each type of cancer, was calculated with Levin's formula. The confidence intervals (CI) were estimated by Monte Carlo simulation.

Results

The prevalence of tobacco consumption in population between 20-79 years old was 33.41% (CI 95% 32.44-34.38) and 9.88% (CI 95% 9.29-10.54) for men and women, respectively. Higher values of PAF were estimated to lung cancer (76.32% in men, 46.99% in women) followed by larynx cancer (69.55% in men, 39.13% in women).The largest number of attributed cases was estimated for lung cancer (1211 in men, 368 in women) and bladder cancer (827 in men, 114 in women). Total cancers attributable to tobacco were superior in men (3776 vs. 677).

Conclusions

In 2008, 4453 of the total common cancers in both sexes could have been avoided if there was no tobacco consumption (current and past). More cancers would have been prevented in men because they smoked more, but also because in most cancers' RR is higher in men. Actually, tobacco consumption has been increasing in women, thus, it is expected that its number of avoided cancers will approximate the one in men. Campaigns with well-defined target populations are important to increase its health level.

Key messages

Tobacco is a modifiable risk factor which can be prevented; thus it is important to promote campaigns in order to prevent early consumption. Secondary data must be used to provide evidence that will help Public Health in taking better decisions regarding interventions.

Impact of influenza vaccination programmes among the elderly population on primary care, Portugal, Spain and the Netherlands: 2015/16 to 2017/18 influenza seasons

Background

To increase the acceptability of influenza vaccine, it is important to quantify the overall benefits of the vaccination programme.

Aim

To assess the impact of influenza vaccination in Portugal, Spain and the Netherlands, we estimated the number of medically attended influenza-confirmed cases (MAICC) in primary care averted in the seasons 2015/16 to 2017/18 among those ≥ 65 years.

Methods

We used an ecological approach to estimate vaccination impact. We compared the number of observed MAICC (n) to the estimated number that would have occurred without the vaccination programme (N). To estimate N, we used: (i) MAICC estimated from influenza surveillance systems, (ii) vaccine coverage, (iii) pooled (sub)type-specific influenza vaccine effectiveness estimates for seasons 2015/16 to 2017/18, weighted by the proportion of virus circulation in each season and country. We estimated the number of MAICC averted (NAE) and the prevented fraction (PF) by the vaccination programme.

Results

The annual average of NAE in the population ≥ 65 years was 33, 58 and 204 MAICC per 100,000 in Portugal, Spain and the Netherlands, respectively. On average, influenza vaccination prevented 10.7%, 10.9% and 14.2% of potential influenza MAICC each season in these countries. The lowest PF was in 2016/17 (4.9–6.1%) with an NAE ranging from 24 to 69 per 100,000.

Conclusions

Our results suggest that influenza vaccination programmes reduced a substantial number of MAICC. Together with studies on hospitalisations and deaths averted by influenza vaccination programmes, this will contribute to the evaluation of the impact of vaccination strategies and strengthen public health communication.

The first Portuguese National Health Examination Survey (2015): design, planning and implementation

BACKGROUND

In Health Examination Surveys interview information is complemented with objective information, providing more accurate indicators than self-reported data. We report the study design, planning and implementation of the first Portuguese Health Examination Survey (INSEF).

METHODS

INSEF was a cross-sectional population-based study representative at regional and national level. Individuals aged between 25 and 74 years old, residing in Portugal were selected from the national health users' registry through multi-stage stratified probabilistic sampling. Sample size was set at 4200 individuals. Data was collected in primary care units and included blood pressure, height, weight, hip and waist measurements, blood collection for lipid profile, HbA1c and blood count and a general health questionnaire. European HES procedures were followed.

RESULTS

A total of 4911 individuals agreed to participate (43.9% participation rate). Participation rate varied by region, sex and age group, being lower in Lisbon and Tagus Valley (32.8%), for men (41.8%) and for those aged 25-34 years old (36%).

CONCLUSIONS

INSEF has set up an experienced national and regional structure for HES implementation. Nationally representative quality epidemiological data is now available for public health monitoring, planning and research.

Understanding influenza vaccination among Portuguese elderly: the social ecological framework

This study intended to identify and quantify the social ecological model (SEM) levels associated to seasonal IV uptake in the Portuguese elderly population. Data from the 2014 National Health Survey was restricted to individuals aged 65+ years (n = 5669). Twenty-three independent variables were allocated to the SEM levels: individual, interpersonal, organizational, community and policy. Sex stratified and age adjusted analysis using Poisson regression were performed for each level and for a fitted full model. Relative reduction in pseudo R magnitude measured marginal contribution of each level. For men and women, older groups (85+ vs. 65–69; men, PR = 1.59 and women, PR = 1.56); having 3+ chronic conditions (men, PR = 1.39 and women, PR = 1.35); previous 4 weeks GP and outpatient visits were associated to higher IV uptake. For men, only 2 SEM levels were associated (individual and organizational) while for women the community level was also relevant. Main marginal contribution came from individual (17.9% and 16.3%) and organizational (30.7% and 22.7%) levels. This study highlights the importance of individual characteristics, access and use of health care services for the IV uptake and the sex differential behaviour.

Healthcare use in patients with multimorbidity

BACKGROUND

The existence of multiple chronic conditions in the same patient is a public health problem increasingly recognized as relevant to health systems. Individuals with multimorbidity have additional health needs, which imply a heavy burden in healthcare use. It is estimated that between 70% and 80% of the total health expenditure is used with chronic conditions. Patients with multimorbidity are responsible for up to 75% of primary care appointments. These patients are also high hospital users, with up to 14.6 times more risk of hospitalization.

METHODS

This study analyses the association between healthcare use and multimorbidity in the Portuguese population aged 25-74 years old. The association between socioeconomic variables and healthcare use was studied, based on data from the first Portuguese Health Examination Survey using a logistic regression model, stratified by sex and adjusted for socioeconomic confounding variables.

RESULTS

In patients with multimorbidity, there was a greater use of primary healthcare consultations, medical or surgical specialist consultations and hospitalizations. An association was established between female, older age groups and lower educational levels, and increased healthcare use. When adjusted to socioeconomic variables, the likelihood of using healthcare services can be as high as 3.5 times, when compared to patients without chronic conditions.

CONCLUSION

Our results show a greater healthcare use in multimorbidity patients, both in primary and hospital care. The availability of scientific evidence regarding the use of healthcare services by multimorbidity patients may support health policy changes, which could allow a more efficient management of these patients.

Effect of lifestyle on blood pressure in patients under antihypertensive medication: An analysis from the Portuguese Health Examination Survey

INTRODUCTION AND OBJECTIVES

Hypertension is one of the main risk factors for disability and death from cardiovascular disease. Current guidelines include initiatives to control blood pressure in hypertensive patients that focus on lifestyle changes. The main objective of this study was to analyze the association between lifestyle and blood pressure in patients under antihypertensive medication.

METHODS

Data collected in the Portuguese National Health Examination Survey (INSEF) were analyzed. Individuals who met INSEF inclusion criteria and reported being under antihypertensive medication in the two weeks prior to the questionnaire were studied. Lifestyle variables (alcohol consumption, smoking, added salt intake, fruit and vegetable consumption, and physical activity) were assessed by questionnaire, and systolic and diastolic blood pressure were measured by physical examination. Associations between lifestyle factors and blood pressure, stratified by gender and adjusted for sociodemographic variables and obesity, were estimated through a multiple linear regression model.

RESULTS

Alcohol consumption (beta=6.31, p=0.007) and smoking (beta=4.72, p=0.018) were positively associated with systolic blood pressure in men. Added salt intake, fruit and vegetable consumption, and physical activity were not associated with blood pressure in men. In women, no association was observed for any behavioral variable.

CONCLUSIONS

These conclusions highlight the need in the population under antihypertensive medication, particularly in men, to focus on the fight against high systolic blood pressure in the two modifiable and preventable behaviors of smoking and alcohol consumption.

Impact of national influenza vaccination strategy in severe influenza outcomes among the high-risk Portuguese population

Background

All aged individuals with a chronic condition and those with 65 and more years are at increased risk of severe influenza post-infection complications. There is limited research on cases averted by the yearly vaccination programs in high-risk individuals. The objective was to estimate the impact of trivalent seasonal influenza vaccination on averted hospitalizations and death among the high-risk population in Portugal.

Methods

The impact of trivalent seasonal influenza vaccination was estimated using vaccine coverage, vaccine effectiveness and the number of influenza-related hospitalizations and deaths. The number of averted events (NAE), prevented fraction (PF) and number needed to vaccinate (NVN) were estimated for seasons 2014/15 to 2016/17.

Results

The vaccination strategy averted on average approximately 1833 hospitalizations and 383 deaths per season. Highest NAE was observed in the ≥65 years population (85% of hospitalizations and 95% deaths) and in the 2016/17 season (1957 hospitalizations and 439 deaths). On average, seasonal vaccination prevented 21% of hospitalizations in the population aged 65 and more, and 18.5% in the population with chronic conditions. The vaccination also prevented 29% and 19.5% of deaths in each group of the high-risk population. It would be needed to vaccinate 3360 high-risk individuals, to prevent one hospitalization and 60,471 high-risk individuals to prevent one death.

Conclusion

The yearly influenza vaccination campaigns had a sustained positive benefit for the high-risk population, reducing hospitalizations and deaths. These results can support public health plans toward increased vaccine coverage in high-risk groups.

Sociodemographic disparities in hypertension prevalence: Results from the first Portuguese National Health Examination Survey

INTRODUCTION

Cardiovascular disease is an important cause of death and disability worldwide, and hypertension is responsible for at least 45% of all deaths due to heart disease and 51% of deaths due to stroke. This study aimed to estimate and describe the distribution of prevalence, awareness, treatment and control of hypertension in the Portuguese population in 2015.

METHODS

A national survey using a representative sample of 4911 individuals residing in Portugal and aged between 25 and 74 years was implemented. Trained nurses performed a health interview and a physical examination, including blood pressure measurement (right arm, three measurements at 1-min intervals). The prevalence of hypertension was stratified by gender, age group, marital status, education, occupation and type of residential area. Associations between hypertension prevalence and sociodemographic factors were assessed using bivariate and multivariate Poisson regression.

RESULTS

The overall hypertension prevalence was 36.0%. The highest rates were observed in males (39.6%), in individuals aged between 65 and 74 years (71.3%), and in those with low levels of education (62.6%) and with no formal occupation (64.5%). Among hypertensive individuals, 69.8% were aware of their condition and 69.4% were under treatment, of whom 71.3% were controlled. Rates of awareness and medical treatment were significantly higher among women and older individuals.

CONCLUSIONS

A large majority of the adult Portuguese population are likely to reach blood pressure levels defined as hypertension in adulthood. Significant differences in hypertension prevalence were found according to gender, age and socioeconomic status, which highlights the importance of population strategies in public health policies.

Effect of lifestyle on blood pressure in Portuguese population under antihypertensive drugs

Background

Hypertension is one of the main risk factors for disability and death from cardiovascular diseases. Current guidelines include initiatives to control blood pressure values in hypertensive patients that focus on lifestyle changes. The main objective of this study was to estimate the association between lifestyle and blood pressure in patients under antihypertensive drugs.

Methods

An analysis of the data of Portuguese Health Examination Survey (INSEF) was performed. Individuals who met INSEF inclusion criteria and who referred to be under antihypertensive drugs in the two weeks prior to the questionnaire were studied. Lifestyle variables (alcohol consumption, smoking, additional salt intake, fruit and vegetables consumption, practice of physical activity) were measured by questionnaire, and blood pressure values were obtained by physical examination. Associations between lifestyle factors and blood pressure, stratified by sex and adjusted to sociodemographic variables and to obesity, were estimated through a multiple linear regression model.

Results

Alcohol consumption (ß=6.31, p = 0.007) and smoking (ß=4.72, p = 0.018) were associated with systolic blood pressure in men. Additional salt intake, fruit and vegetable consumption, and practice of physical activity were not associated with blood pressure in men. In women, no association was observed for any behavioural variable.

Conclusions

These conclusions reinforce the need, also in the population under antihypertensive drugs, particularly in the male sex, to focus the fight against high systolic blood pressure in these two modifiable and preventable behaviours: smoking and alcoholic consumption.

Key messages

Alcohol consumption and smoking are the behavioral determinants associated with high systolic blood pressure values in men under antihypertensive drugs. These conclusions reinforce the need to focus the fight against high systolic blood pressure in the preventable and modifiable behavioural determinants.