Ausenda Machado

Excess Mortality Associated with Influenza Epidemics in Portugal, 1980 to 2004

Background Influenza epidemics have a substantial impact on human health, by increasing the mortality from pneumonia and influenza, respiratory and circulatory diseases, and all causes. This paper provides estimates of excess mortality rates associated with influenza virus circulation for 7 causes of death and 8 age groups in Portugal during the period of 1980–2004. Methodology/Principal Findings We compiled monthly mortality time series data by age for all-cause mortality, cerebrovascular diseases, ischemic heart diseases, diseases of the respiratory system, chronic respiratory diseases, pneumonia and influenza. We also used a control outcome, deaths from injuries. Age- and cause-specific baseline mortality was modelled by the ARIMA approach; excess deaths attributable to influenza were calculated by subtracting expected deaths from observed deaths during influenza epidemic periods. Influenza was associated with a seasonal average of 24.7 all-cause excess deaths per 100,000 inhabitants, approximately 90% of which were among seniors over 65 yrs. Excess mortality was 3–6 fold higher during seasons dominated by the A(H3N2) subtype than seasons dominated by A(H1N1)/B. High excess mortality impact was also seen in children under the age of four years. Seasonal excess mortality rates from all the studied causes of death were highly correlated with each other (Pearson correlation range, 0.65 to 0.95, P<0.001) and with seasonal rates of influenza-like-illness (ILI) among seniors over 65 years (Pearson correlation rho>0.64, P<0.05). By contrast, there was no correlation with excess mortality from injuries. Conclusions/Significance Our excess mortality approach is specific to influenza virus activity and produces influenza-related mortality rates for Portugal that are similar to those published for other countries. Our results indicate that all-cause excess mortality is a robust indicator of influenza burden in Portugal, and could be used to monitor the impact of influenza epidemics in this country. Additional studies are warranted to confirm these findings in other settings.

The European I-MOVE Multicentre 2013-2014 Case-Control Study. Homogeneous moderate influenza vaccine effectiveness against A(H1N1)pdm09 and heterogenous results by country against A(H3N2)

BACKGROUND In the first five I-MOVE (Influenza Monitoring Vaccine Effectiveness in Europe) influenza seasons vaccine effectiveness (VE) results were relatively homogenous among participating study sites. In 2013-2014, we undertook a multicentre case-control study based on sentinel practitioner surveillance networks in six European Union (EU) countries to measure 2013-2014 influenza VE against medically-attended influenza-like illness (ILI) laboratory-confirmed as influenza. Influenza A(H3N2) and A(H1N1)pdm09 viruses co-circulated during the season. METHODS Practitioners systematically selected ILI patients to swab within eight days of symptom onset. We compared cases (ILI positive to influenza A(H3N2) or A(H1N1)pdm09) to influenza negative patients. We calculated VE for the two influenza A subtypes and adjusted for potential confounders. We calculated heterogeneity between sites using the I(2) index and Cochranes Q test. If the I(2) was <50%, we estimated pooled VE as (1 minus the OR)×100 using a one-stage model with study site as a fixed effect. If the I(2) was >49% we used a two-stage random effects model. RESULTS We included in the A(H1N1)pdm09 analysis 531 cases and 1712 controls and in the A(H3N2) analysis 623 cases and 1920 controls. For A(H1N1)pdm09, the Q test (p=0.695) and the I(2) index (0%) suggested no heterogeneity of adjusted VE between study sites. Using a one-stage model, the overall pooled adjusted VE against influenza A(H1N1)pdm2009 was 47.5% (95% CI: 16.4-67.0). For A(H3N2), the I(2) was 51.5% (p=0.067). Using a two-stage model for the pooled analysis, the adjusted VE against A(H3N2) was 29.7 (95% CI: -34.4-63.2). CONCLUSIONS The results suggest a moderate 2013-2014 influenza VE against A(H1N1)pdm09 and a low VE against A(H3N2). The A(H3N2) estimates were heterogeneous among study sites. Larger sample sizes by study site are needed to prevent statistical heterogeneity, decrease variability and allow for two-stage pooled VE for all subgroup analyses.

I-MOVE multicentre case–control study 2010/11 to 2014/15 : is there within-season waning of influenza type/subtype vaccine effectiveness with increasing time since vaccination?

Since the 2008/9 influenza season, the I-MOVE multicentre case-control study measures influenza vaccine effectiveness (VE) against medically-attended influenza-like-illness (ILI) laboratory confirmed as influenza. In 2011/12, European studies reported a decline in VE against influenza A(H3N2) within the season. Using combined I-MOVE data from 2010/11 to 2014/15 we studied the effects of time since vaccination on influenza type/subtype-specific VE. We modelled influenza type/subtype-specific VE by time since vaccination using a restricted cubic spline, controlling for potential confounders (age, sex, time of onset, chronic conditions). Over 10,000 ILI cases were included in each analysis of influenza A(H3N2), A(H1N1)pdm09 and B; with 4,759, 3,152 and 3,617 influenza positive cases respectively. VE against influenza A(H3N2) reached 50.6% (95% CI: 30.0-65.1) 38 days after vaccination, declined to 0% (95% CI: -18.1-15.2) from 111 days onwards. At day 54 VE against influenza A(H1N1)pdm09 reached 55.3% (95% CI: 37.9-67.9) and remained between this value and 50.3% (95% CI: 34.8-62.1) until season end. VE against influenza B declined from 70.7% (95% CI: 51.3-82.4) 44 days after vaccination to 21.4% (95% CI: -57.4-60.8) at season end. To assess if vaccination campaign strategies need revising more evidence on VE by time since vaccination is urgently needed.

Consumo de tabaco na população portuguesa retratado pelo Inquérito Nacional de Saúde (2005/2006)

Resumo O presente estudo visa contribuir para o conhecimento da epidemiologia da exposicao ao tabaco na populacao portuguesa, atraves da analise de dados do Inquerito Nacional de Saude realizado entre 2005 e 2006. Neste trabalho, a populacao portuguesa e caracterizada quanto a prevalencia de fumadores, ex-fumadores e nao fumadores e quanto a exposicao e atitudes face ao fumo do tabaco. Algumas destas caracteristicas sao desagregadas por variaveis sociodemograficas, como o sexo, a idade e a regiao de residencia. As frequencias apresentadas expressam valores estimados para a populacao residente em Portugal no ano de 2005. Atraves de regressao logistica binaria construiram-se perfis dos fumadores. Os resultados revelaram que 20,9% da populacao com 15 e mais anos de idade, residente em Portugal (incluindo as regioes autonomas), era fumadora a data da entrevista (sexo masculino: 30,9%; sexo feminino: 11,8%) e que 18,7% fumava diariamente. Mais de metade dos homens fumava, ou ja tinha fumado (56,9%), ao contrario das mulheres que, na grande maioria, nunca tinha fumado (81,3%). Apos remocao do efeito ocasionado pela diferente estrutura etaria, as prevalencias mais elevadas de homens que fumavam diariamente foram observadas nos Acores (31,0%) e no Alentejo (29,9%). Ja entre as mulheres, a prevalencia mais elevada de consumo diario de tabaco ocorreu na regiao de Lisboa e Vale do Tejo (15,4%), seguida do Algarve (12,8%). Em media, os homens fumavam mais cigarros por dia (20 cigarros) do que as mulheres (13 cigarros). A populacao acoriana evidenciou os consumos medios diarios mais elevados (homens: 23 cigarros; mulheres: 16 cigarros). Rev Port Pneumol 2009; XV (6): 1005-1027

Tobacco consumption by the portuguese population. Data from the 2005–2006 National Health Survey

This study aims to contribute to the epidemiological portrayal of tobacco consumption in Portugal 2005- 2006, using data from the National Health Survey. In this analysis the Portuguese population is characterised according to smoking patterns, exposure to smoke and attitudes to smoking in general. Data is presented by gender, age groups, regions of residence and other social characteristics. Frequencies results are estimated values for the Portuguese population in 2005. Logistic binary regression models are used to study regular smoking-related characteristics. Results show that 20.9% of the Portuguese population (including Madeira and the Azores) aged 15 or more were smokers (male: 30.9%; female: 11.8%), and that 18.7% smoked regularly. More than one half of men were smokers or ex-smokers (56.9%) whereas the great majority of women had never smoked (81.3%). After removing the effect of the different age structures among regions, the highest rate of males who smoked regularly was observed in the Azores region (31.0%), followed by the Alentejo region (29.9%). The highest rate of women who smoked regularly occurred in the Lisbon and Tagus Valley region (15.4%), followed by the Algarve region (12.8%). Daily average cigarette consumption was higher among male (20 cigarettes) than female smokers (13 cigarettes). The Azores population presented the highest daily average consumption (male: 23 cigarettes; female: 16 cigarettes).

Estimates of 2012/13 influenza vaccine effectiveness using the case test-negative control design with different influenza negative control groups

BACKGROUND In recent years several reports of influenza vaccine effectiveness (VE) have been made early for public health decision. The majority of these studies use the case test-negative control design (TND), which has been showed to provide, under certain conditions, unbiased estimates of influenza VE. Nevertheless, discussions have been taken on the best influenza negative control group to use. The present study aims to contribute to the knowledge on this field by comparing influenza VE estimates using three test-negative controls: all influenza negative, non-influenza respiratory virus and pan-negative. METHODS Incident ILI patients were prospectively selected and swabbed by a sample of general practitioners. Cases were ILI patients tested positive for influenza and controls ILI patients tested negative for influenza. The influenza negative control group was divided into non-influenza virus control group and pan-negative control group. Data were collected on vaccination status and confounding factors. Influenza VE was estimated as one minus the odds ratio of been vaccinated in cases versus controls adjusted for confounding effect by logistic regression. RESULTS Confounder adjusted influenza VE against medically attended laboratory-confirmed influenza was 68.4% (95% CI: 20.7-87.4%) using all influenza negatives controls, 82.1% (95% CI: 47.6-93.9%) using non-influenza controls and 49.4% (95% CI: -44.7% to 82.3%) using pan-negative controls. CONCLUSIONS Influenza VE estimates differed according to the influenza negative control group used. These results are in accordance with the expected under the hypothesis of differential viral interference between influenza vaccinated and unvaccinated individuals. Given the wide importance of TND study further studies should be conducted in order to clarify the observed differences.

Performance of Synthetic and Mineral Soluble Oil When Turning AISI 8640 Steel

The present work shows a comparative study of the application of synthetic and semi synthetic, mineral soluble oil (at concentrations of 3 and 10 percent) as well as dry cut when turning AISI 8640 steel bars with triple coated (TiC,Al2 O3 ,TiN) P35 grade of cemented carbide tools. Tool lives, cutting forces, cutting temperatures and surface roughness were considered to evaluate the cutting fluids. Generally, the semi-synthetic gave longer tool life based on flank wear parameter VB. The surface roughness was not sensitive to the lubrication quality, if wear effects are not considered. Mean tool-chip interface temperature was lower with the synthetic fluid, followed by the semi-synthetic, mineral soluble oils and dry cutting, respectively. The inverse of this order was true for the cutting forces.

2015/16 seasonal vaccine effectiveness against hospitalisation with influenza A(H1N1)pdm09 and B among elderly people in Europe: results from the I-MOVE+ project

We conducted a multicentre test-negative case–control study in 27 hospitals of 11 European countries to measure 2015/16 influenza vaccine effectiveness (IVE) against hospitalised influenza A(H1N1)pdm09 and B among people aged ≥ 65 years. Patients swabbed within 7 days after onset of symptoms compatible with severe acute respiratory infection were included. Information on demographics, vaccination and underlying conditions was collected. Using logistic regression, we measured IVE adjusted for potential confounders. We included 355 influenza A(H1N1)pdm09 cases, 110 influenza B cases, and 1,274 controls. Adjusted IVE against influenza A(H1N1)pdm09 was 42% (95% confidence interval (CI): 22 to 57). It was 59% (95% CI: 23 to 78), 48% (95% CI: 5 to 71), 43% (95% CI: 8 to 65) and 39% (95% CI: 7 to 60) in patients with diabetes mellitus, cancer, lung and heart disease, respectively. Adjusted IVE against influenza B was 52% (95% CI: 24 to 70). It was 62% (95% CI: 5 to 85), 60% (95% CI: 18 to 80) and 36% (95% CI: -23 to 67) in patients with diabetes mellitus, lung and heart disease, respectively. 2015/16 IVE estimates against hospitalised influenza in elderly people was moderate against influenza A(H1N1)pdm09 and B, including among those with diabetes mellitus, cancer, lung or heart diseases.

Low 2016/17 season vaccine effectiveness against hospitalised influenza A(H3N2) among elderly: awareness warranted for 2017/18 season

In a multicentre European hospital study we measured influenza vaccine effectiveness (IVE) against A(H3N2) in 2016/17. Adjusted IVE was 17% (95% confidence interval (CI): 1 to 31) overall; 25% (95% CI: 2 to 43) among 65–79-year-olds and 13% (95% CI: −15 to 30) among those ≥ 80 years. As the A(H3N2) vaccine component has not changed for 2017/18, physicians and public health experts should be aware that IVE could be low where A(H3N2) viruses predominate.

Excess pneumonia and influenza hospitalizations associated with influenza epidemics in Portugal from season 1998/1999 to 2014/2015

The aim of this study was to estimate excess pneumonia and influenza (P&I) hospitalizations during influenza epidemics and measure their correlation with influenza vaccine coverage in the 65 and more years old, according to the type/subtype of influenza virus.