Excess mortality among the elderly in European countries, December 2014 to February 2015.

Since December 2014 and up to February 2015, the weekly number of excess deaths from all-causes among individuals ≥ 65 years of age in 14 European countries have been significantly higher than in the four previous winter seasons. The rise in unspecified excess mortality coincides with increased proportion of influenza detection in the European influenza surveillance schemes with a main predominance of influenza A (H3N2) viruses seen throughout Europe in the current season, though cold snaps and other respiratory infections may also have had an effect.

Pooling European all-cause mortality: methodology and findings for the seasons 2008/2009 to 2010/2011.

Several European countries have timely all-cause mortality monitoring. However, small changes in mortality may not give rise to signals at the national level. Pooling data across countries may overcome this, particularly if changes in mortality occur simultaneously. Additionally, pooling may increase the power of monitoring populations with small numbers of expected deaths, e.g. younger age groups or fertile women. Finally, pooled analyses may reveal patterns of diseases across Europe. We describe a pooled analysis of all-cause mortality across 16 European countries. Two approaches were explored. In the 'summarized' approach, data across countries were summarized and analysed as one overall country. In the 'stratified' approach, heterogeneities between countries were taken into account. Pooling using the 'stratified' approach was the most appropriate as it reflects variations in mortality. Excess mortality was observed in all winter seasons albeit slightly higher in 2008/09 than 2009/10 and 2010/11. In the 2008/09 season, excess mortality was mainly in elderly adults. In 2009/10, when pandemic influenza A(H1N1) dominated, excess mortality was mainly in children. The 2010/11 season reflected a similar pattern, although increased mortality in children came later. These patterns were less clear in analyses based on data from individual countries. We have demonstrated that with stratified pooling we can combine local mortality monitoring systems and enhance monitoring of mortality across Europe.

Excess mortality among the elderly in 12 European countries, February and March 2012.

In February and March 2012, excess deaths among the elderly have been observed in 12 European countries that carry out weekly monitoring of all-cause mortality. These preliminary data indicate that the impact of influenza in Europe differs from the recent pandemic and post-pandemic seasons. The current excess mortality among the elderly may be related to the return of influenza A(H3N2) virus, potentially with added effects of a cold snap.

Higher all-cause mortality in children during autumn 2009 compared with the three previous years: pooled results from eight European countries.

The paper describes weekly fluctuations of all-cause mortality observed in eight European countries during the period between week 27 and 51, 2009, in comparison with three previous years. Our preliminary data show that the mortality reported during the 2009 influenza pandemic did not reach levels normally seen during seasonal influenza epidemics. However, there was a cumulative excess mortality of 77 cases (1 per 100,000 population) in 5-14-year-olds, and possibly also among 0-4-year-olds.

Experience and lessons from surveillance and studies of the 2009 pandemic in Europe.

Surveillance and studies in a pandemic is a complex topic including four distinct components: (1) early detection and investigation; (2) comprehensive early assessment; (3) monitoring; and (4) rapid investigation of the effectiveness and impact of countermeasures, including monitoring the safety of pharmaceutical countermeasures. In the 2009 pandemic, the prime early detection and investigation took place in the Americas, but Europe needed to undertake the other three components while remaining vigilant to new phenomenon such as the emergence of antiviral resistance and important viral mutation. Laboratory-based surveillance was essential and also integral to epidemiological and clinical surveillance. Early assessment was especially vital because of the many important strategic parameters of the pandemic that could not be anticipated (the 'known unknowns'). Such assessment did not need to be undertaken in every country, and was done by the earliest affected European countries, particularly those with stronger surveillance. This was more successful than requiring countries to forward primary data for central analysis. However, it sometimes proved difficult to get even those analyses from European counties, and information from Southern hemisphere countries and North America proved equally valuable. These analyses informed which public health and clinical measures were most likely to be successful, and were summarized in a European risk assessment that was updated repeatedly. The estimate of the severity of the pandemic by the World Health Organization (WHO), and more detailed description by the European Centre for Disease Prevention and Control in the risk assessment along with revised planning assumptions were essential, as most national European plans envisaged triggering more disruptive interventions in the event of a severe pandemic. Setting up new surveillance systems in the midst of the pandemic and getting information from them was generally less successful. All European countries needed to perform monitoring (Component 3) for the proper management of their own healthcare systems and other services. The information that central authorities might like to have for monitoring was legion, and some countries found it difficult to limit this to what was essential for decisions and key communications. Monitoring should have been tested for feasibility in influenza seasons, but also needed to consider what surveillance systems will change or cease to deliver during a pandemic. International monitoring (reporting upwards to WHO and European authorities) had to be kept simple as many countries found it difficult to provide routine information to international bodies as well as undertaking internal processes. Investigation of the effectiveness of countermeasures (and the safety of pharmaceutical countermeasures) (Component 4) is another process that only needs to be undertaken in some countries. Safety monitoring proved especially important because of concerns over the safety of vaccines and antivirals. It is unlikely that it will become clear whether and which public health measures have been successful during the pandemic itself. Piloting of methods of estimating influenza vaccine effectiveness (part of Component 4) in Europe was underway in 2008. It was concluded that for future pandemics, authorities should plan how they will undertake Components 2-4, resourcing them realistically and devising new ways of sharing analyses.

"I-MOVE" towards monitoring seasonal and pandemic influenza vaccine effectiveness: lessons learnt from a pilot multi-centric case-control study in Europe, 2008-9.

Within I-MOVE (European programme to monitor seasonal and pandemic influenza vaccine effectiveness (IVE)) five countries conducted IVE pilot case-control studies in 2008-9. One hundred and sixty sentinel general practitioners (GP) swabbed all elderly consulting for influenza-like illness (ILI). Influenza confirmed cases were compared to influenza negative controls. We conducted a pooled analysis to obtain a summary IVE in the age group of >or=65 years. We measured IVE in each study and assessed heterogeneity between studies qualitatively and using the I2 index. We used a one-stage pooled model with study as a fixed effect. We adjusted estimates for age-group, sex, chronic diseases, smoking, functional status, previous influenza vaccinations and previous hospitalisations. The pooled analysis included 138 cases and 189 test-negative controls. There was no statistical heterogeneity (I2=0) between studies but ILI case definition, previous hospitalisations and functional status were slightly different. The adjusted IVE was 59.1% (95% CI: 15.3-80.3%). IVE was 65.4% (95% CI: 15.6-85.8%) in the 65-74, 59.6% (95% CI: -72.6 -90.6%) in the age group of >or=75 and 56.4% (95% CI: -0.2-81.3%) for A(H3). Pooled analysis is feasible among European studies. The variables definitions need further standardisation. Larger sample sizes are needed to achieve greater precision for subgroup analysis. For 2009-10, I-MOVE will extend the study to obtain early IVE estimates in groups targeted for pandemic H1N1 influenza vaccination.

Start of the influenza season 2008-9 in Europe - increasing influenza activity moving from West to East dominated by A(H3N2).

The influenza season 2008-9 started in week 49 of 2008 and is so far characterised by influenza virus type A subtype H3N2. Isolates of this subtype that were tested proved susceptible to neuraminidase inhibitors, but resistant to M2 inhibitors. The circulating A(H3N2) viruses are antigenically similar to the component in the current northern hemisphere influenza vaccine.

Using sentinel surveillance to monitor effectiveness of influenza vaccine is feasible: a pilot study in Denmark.

The influenza vaccine for the season 2003/04 did not contain the circulating A(H3N2)/Fujian virus strain. Vaccine effectiveness (VE) estimates were needed but unavailable. We explored whether or not laboratory based influenza surveillance can be used to estimate VE. We carried out a case-control study nested within Danish sentinel surveillance. A case was defined as a person aged 25 or above with A(H3N2)/Fujian/411/02 influenza. Four controls per case, matched on age groups and time, were selected from clients of sentinel practitioners (SP) who reported cases. SPs collected the following data in structured one-page questionnaires: vaccination status, chronic illness and previous pneumococcal vaccination. We sent postal survey questionnaires to participating SPs to assess acceptability and simplicity of data collection. Twenty four cases were identified. Data from 19 case-control sets were analysed. One control was excluded because information on vaccination status was missing. Two of the 19 cases and 11 of 75 controls had been vaccinated against influenza. The VE adjusted for chronic illness was 33% (95% CI 0%-88%) and 37% (95% CI 0%-89%) when excluding 5 controls with influenza-like illness. Twenty two SPs returned survey questionnaires. Fifteen of 17 SPs reported that it was easy to find controls. SPs collected data through interviews and clinical notes, spending 1 to 5 minutes per case and 5 to 15 minutes for all four controls. Nineteen of 22 SPs considered the amount of time they spent on the study to be acceptable, 17 said that they would like to participate again, and none ruled out further participation. Monitoring VE within sentinel surveillance systems is feasible. The small numbers in our study limit interpretation of VE. Expansion to a European multicountry study could overcome this limitation and provide VE estimates earlier in the season, for different age groups and emerging virus strains, including new and pandemic subtypes.

An outbreak of Campylobacter jejuni associated with consumption of chicken, Copenhagen, 2005.

In May/June 2005 an outbreak of diarrhoeal illness occurred among company employees in Copenhagen. Cases were reported from seven of eight companies that received food from the same catering kitchen. Stool specimens from three patients from two companies were positive for Campylobacter jejuni. We performed a retrospective cohort study among employees exposed to canteen food in the three largest companies to identify the source of the outbreak and to prevent further spread. Using self-administered questionnaires we collected information on disease, days of canteen food eaten and food items consumed. The catering kitchen was inspected and food samples were taken. Questionnaires were returned by 295/348 (85%) employees. Of 247 employees who ate canteen food, 79 were cases, and the attack rate (AR) was 32%. Consuming canteen food on 25 May was associated with illness (AR 75/204, RR=3.2, 95%CI 1.3-8.2). Consumption of chicken salad on this day, but not other types of food, was associated with illness (AR=43/97, RR=2.3, 95%CI 1.3-4.1). Interviews with kitchen staff indicated the likelihood of cross-contamination from raw chicken to the chicken salad during storage. This is the first recognised major Campylobacter outbreak associated with contaminated chicken documented in Denmark. It is plausible that food handling practices contributed to transmission, and awareness of safe food handling and storage has since been raised among kitchen staff. The low number of positive specimens accrued in this outbreak suggests a general underascertainment of adult cases in the laboratory reporting system by a factor of 20.

Hepatitis A vaccination policy for travellers to Egypt in eight European countries, 2004.

In 2004, an outbreak of hepatitis A occurred in European tourists returning from Egypt. The reported hepatitis A attack rates varied considerably between tourists from different European countries. To determine the reason for this divergence in attack rates, a survey was undertaken with the following objectives: (a) documentation of national hepatitis A prevention policies for people travelling to Egypt and (b) documentation of hepatitis A reporting practices in these countries. A questionnaire was compiled and distributed to 13 European countries. All eight of the countries that responded had produced guidelines for the prevention of travel-associated hepatitis A. Between 2001-2003, 40% (range 4-51) of hepatitis A cases reported annually were associated with travel abroad. This occurred despite the fact that all countries recommended active vaccination with hepatitis A vaccine for people travelling to Egypt for holidays. There was no standard case definition for reporting confirmed cases in the countries that reported hepatitis A cases. As it is likely that travel-associated infections will increase as more people take overseas holidays, innovative ways to increase the number of travellers who seek and adhere to appropriate medical advice prior to travel must be explored. In addition, we recommend the use of the European Commission case definition for notification of confirmed cases of hepatitis A.

An outbreak of Campylobacter jejuni associated with consumption of chicken, Copenhagen, 2005.

In May/June 2005 an outbreak of diarrhoeal illness occurred among company employees in Copenhagen. Cases were reported from seven of eight companies that received food from the same catering kitchen. Stool specimens from three patients from two companies were positive for Campylobacter jejuni. We performed a retrospective cohort study among employees exposed to canteen food in the three largest companies to identify the source of the outbreak and to prevent further spread. Using self-administered questionnaires we collected information on disease, days of canteen food eaten and food items consumed. The catering kitchen was inspected and food samples were taken. Questionnaires were returned by 295/348 (85%) employees. Of 247 employees who ate canteen food, 79 were cases, and the attack rate (AR) was 32%. Consuming canteen food on 25 May was associated with illness (AR 75/204, RR=3.2, 95%CI 1.3-8.2). Consumption of chicken salad on this day, but not other types of food, was associated with illness (AR=43/97, RR=2.3, 95%CI 1.3-4.1). Interviews with kitchen staff indicated the likelihood of cross-contamination from raw chicken to the chicken salad during storage. This is the first recognised major Campylobacter outbreak associated with contaminated chicken documented in Denmark. It is plausible that food handling practices contributed to transmission, and awareness of safe food handling and storage has since been raised among kitchen staff. The low number of positive specimens accrued in this outbreak suggests a general underascertainment of adult cases in the laboratory reporting system by a factor of 20.

Using sentinel surveillance to monitor effectiveness of influenza vaccine is feasible: A pilot study in Denmark.

The influenza vaccine for the season 2003/04 did not contain the circulating A(H3N2)/Fujian virus strain. Vaccine effectiveness (VE) estimates were needed but unavailable. We explored whether or not laboratory based influenza surveillance can be used to estimate VE. We carried out a case-control study nested within Danish sentinel surveillance. A case was defined as a person aged 25 or above with A(H3N2)/Fujian/411/02 influenza. Four controls per case, matched on age groups and time, were selected from clients of sentinel practitioners (SP) who reported cases. SPs collected the following data in structured one-page questionnaires: vaccination status, chronic illness and previous pneumococcal vaccination. We sent postal survey questionnaires to participating SPs to assess acceptability and simplicity of data collection. Twenty four cases were identified. Data from 19 case-control sets were analysed. One control was excluded because information on vaccination status was missing. Two of the 19 cases and 11 of 75 controls had been vaccinated against influenza. The VE adjusted for chronic illness was 33% (95% CI 0%-88%) and 37% (95% CI 0%-89%) when excluding 5 controls with influenza-like illness. Twenty two SPs returned survey questionnaires. Fifteen of 17 SPs reported that it was easy to find controls. SPs collected data through interviews and clinical notes, spending 1 to 5 minutes per case and 5 to 15 minutes for all four controls. Nineteen of 22 SPs considered the amount of time they spent on the study to be acceptable, 17 said that they would like to participate again, and none ruled out further participation. Le contrôle de l'EV au sein des systèmes de surveillance sentinelle est faisable. Les nombres restreints de notre étude limitent l'interprétation de l'EV. Une étude étendue à l'échelle européenne, comprenant plusieurs pays, pourrait surmonter cette limitation et offrir des évaluations de l'efficacité vaccinale plus tôt dans la saison, pour différents groupes d'âge et pour des souches virales émergentes, incluant les sous-types nouveaux et pandémiques. Monitoring VE within sentinel surveillance systems is feasible. The small numbers in our study limit interpretation of VE. Expansion to a European multicountry study could overcome this limitation and provide VE estimates earlier in the season, for different age groups and emerging virus strains, including new and pandemic subtypes.

Hepatitis A vaccination policy for travellers to Egypt in eight European countries, 2004.

In 2004, an outbreak of hepatitis A occurred in European tourists returning from Egypt. The reported hepatitis A attack rates varied considerably between tourists from different European countries. To determine the reason for this divergence in attack rates, a survey was undertaken with the following objectives: (a) documentation of national hepatitis A prevention policies for people travelling to Egypt and (b) documentation of hepatitis A reporting practices in these countries. A questionnaire was compiled and distributed to 13 European countries. All eight of the countries that responded had produced guidelines for the prevention of travel-associated hepatitis A. Between 2001-2003, 40% (range 4-51) of hepatitis A cases reported annually were associated with travel abroad. This occurred despite the fact that all countries recommended active vaccination with hepatitis A vaccine for people travelling to Egypt for holidays. There was no standard case definition for reporting confirmed cases in the countries that reported hepatitis A cases. As it is likely that travel-associated infections will increase as more people take overseas holidays, innovative ways to increase the number of travellers who seek and adhere to appropriate medical advice prior to travel must be explored. In addition, we recommend the use of the European Commission case definition for notification of confirmed cases of hepatitis A.

Hepatitis A outbreak among MSM linked to casual sex and gay saunas in Copenhagen, Denmark.

During an outbreak of hepatitis A predominantly among men who have sex with men (MSM) in Copenhagen, Denmark, in 2004, we did a case-control study to determine risk factors for infection. A case was an MSM >17 years, living in Copenhagen, with IgM positive hepatitis A infection diagnosed between June and August 2004, and without a household contact with a hepatitis A case before onset of illness. Controls were selected at the Copenhagen Pride Festival. The study included 18 cases and 64 controls. Sixteen of 18 cases and 36/63 controls had sex with casual partners (ORMH 5.6, 95% CI 1.2-26.9). Eleven of 18 cases and 14/62 controls had sex in gay saunas (ORMH 4.2, 95% CI 1.5-11.5). Sex at private homes appeared to be protective (ORMH 0.2, 95% CI 0.1-0.7). Casual sex including sex in gay saunas was an important risk factor for the spread of HAV among MSM in Copenhagen. The results are in accordance with findings in other European outbreaks. As the general immunity to hepatitis A decreases and the outbreak potential increases, we recommend health education and hepatitis A vaccination to all MSM not living in monogamous relationships, especially if they visit gay saunas or other places with frequent partner change. To stop spread of hepatitis A among MSM in Europe, a European consensus on prevention and control measures may be required.

Hepatitis A outbreak among MSM linked to casual sex and gay saunas in Copenhagen, Denmark.

During an outbreak of hepatitis A predominantly among men who have sex with men (MSM) in Copenhagen, Denmark, in 2004, we did a case-control study to determine risk factors for infection. A case was an MSM >17 years, living in Copenhagen, with IgM positive hepatitis A infection diagnosed between June and August 2004, and without a household contact with a hepatitis A case before onset of illness. Controls were selected at the Copenhagen Pride Festival. The study included 18 cases and 64 controls. Sixteen of 18 cases and 36/63 controls had sex with casual partners (ORMH 5.6, 95% CI 1.2-26.9). Eleven of 18 cases and 14/62 controls had sex in gay saunas (ORMH 4.2, 95% CI 1.5-11.5). Sex at private homes appeared to be protective (ORMH 0.2, 95% CI 0.1-0.7). Casual sex including sex in gay saunas was an important risk factor for the spread of HAV among MSM in Copenhagen. The results are in accordance with findings in other European outbreaks. As the general immunity to hepatitis A decreases and the outbreak potential increases, we recommend health education and hepatitis A vaccination to all MSM not living in monogamous relationships, especially if they visit gay saunas or other places with frequent partner change. To stop spread of hepatitis A among MSM in Europe, a European consensus on prevention and control measures may be required.