Browsing by Author "Rodrigues, AP"
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- Cross-Protection to New Drifted Influenza A(H3) Viruses and Prevalence of Protective Antibodies to Seasonal Influenza, During 2014 in PortugalPublication . Guiomar, R; Pereira da Silva, S; Conde, P; Cristóvão, P; Maia, AC; Pechirra, P; Rodrigues, AP; Nunes, B; Milho, L; Coelho, AP; Fernandes, A; Caseiro, P; Rodrigues, F; Correia, L; Pereira-Vaz, J; Almeida, S; Branquinho, P; Côrte-Real, R; Viseu, R; Peres, MJ; Sanches, R; Dantas, F; Freitas, L; Andrade, G; Maurílio, M; Caldeira, F; Cabral Veloso, R; Mota-Vieira, L; Soares, M; Couto, AR; Bruges-Armas, J; Mouro Pinto, R; Sobrinho Simões, J; Costa, MR; Guimarães, JT; Martins, L; Cunha, MINTRODUCTION: Immune profile for influenza viruses is highly changeable over time. Serological studies can assess the prevalence of influenza, estimate the risk of infection, highlight asymptomatic infection rate and can also provide data on vaccine coverage. The aims of the study were to evaluate pre-existing cross-protection against influenza A(H3) drift viruses and to assess influenza immunity in the Portuguese population. MATERIALS AND METHODS: We developed a cross-sectional study based on a convenience sample of 626 sera collected during June 2014, covering all age groups, both gender and all administrative health regions of Portugal. Sera antibody titers for seasonal and new A(H3) drift influenza virus were evaluated by hemagglutination inhibition assay (HI). Seroprevalence to each seasonal influenza vaccine strain virus and to the new A(H3) drift circulating strain was estimated by age group, gender and region and compared with seasonal influenza-like illness (ILI) incidence rates before and after the study period. RESULTS: Our findings suggest that seroprevalences of influenza A(H3) (39.9%; 95% CI: 36.2-43.8) and A(H1)pdm09 (29.7%; 95% CI: 26.3-33.4) antibodies were higher than for influenza B, in line with high ILI incidence rates for A(H3) followed by A(H1)pdm09, during 2013/2014 season. Low pre-existing cross-protection against new A(H3) drift viruses were observed in A(H3) seropositive individuals (46%). Both against influenza A(H1)pdm09 and A(H3) seroprotection was highest in younger than 14-years old. Protective antibodies against influenza B were highest in those older than 65years old, especially for B/Yamagata lineage, 33.3% (95% CI: 25.7-41.9). Women showed a high seroprevalence to influenza, although without statistical significance, when compared to men. A significant decreasing trend in seroprotection from north to south regions of Portugal mainland was observed. CONCLUSIONS: Our results emphasize that low seroprotection increases the risk of influenza infection in the following winter season. Seroepidemiological studies can inform policy makers on the need for vaccination and additional preventive measures.
- Um Hospital, um Serviço para CriançasPublication . Carvalho, J; Ferreira, P; Morais, A; Moura, S; Ribeiro, L; Rodrigues, AP
- Seroprevalence of SARS-CoV-2 Infection in Portugal in May-July 2020: Results of the First National Serological Survey (ISNCOVID-19)Publication . Kislaya, I; Gonçalves, P; Barreto, M; Sousa, R; Garcia, AC; Matos, R; Guiomar, R; Rodrigues, AP; Dias, AIntroduction: 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.