Detection of Influenza in the Epidemic Season 2016/2017 Based on I-MOVE+ Project.

In the influenza season 2016/2017 in Europe, the predominant virus was A/H3N2/. In Poland, the percentage of people vaccinated against influenza was 3.33%. European I-MOVE+ project shows how important it is to monitor the effectiveness of influenza vaccine. The project demonstrates that a match between the circulating vaccine strains and those included in the vaccine for the Northern Hemisphere was low-to-moderate. In the present study, there were 379 patients and 296 control subjects examined in hospitals in Poland as part of I-MOVE+ project. The real-time reverse transcription polymerase chain reaction (qRT-PCR) method was used to detect the influenza virus in all subjects. We detected the influenza subtype A/H3N2/ in 59.1% and type B virus in 2.1%. There was one co-infection of subtype A/H3N2/ with subtype A/H1N1/ and eight co-infections of type B with subtype A/H3N2/. No influenza viruses were detected in the control group. Only 19 patients and 22 control subjects were vaccinated during the epidemic season in question. A proportion of people vaccinated against influenza in Poland remains dismally low compared to other European countries.

Virological Characteristics of the 2014/2015 Influenza Season Based on Molecular Analysis of Biological Material Derived from I-MOVE Study.

The main goal of the international study I-MOVE (Influenza Monitoring of Vaccine Effectiveness) implemented in Poland is to identify and evaluate the activity types of influenza virus and to determine the effectiveness of vaccination against influenza in the 2014-2015 influenza season. The study is based on selecting patients with flu symptoms and collecting biological samples for laboratory examination. Detection, typing, and subtyping of influenza viruses were carried out by the National Center for Influenza Virus Research at National Institute of Public Health - National Institute of Hygiene, serving as a reference center, and also in selected laboratories of the Regional Sanitary Epidemiological Stations. Molecular biology methods, such as reverse transcription polymerase chain reaction (RT-PCR), were applied in this study. A total of 218 samples were collected. A hundred and twenty six samples, representing 57.8 % of the total, were confirmed with influenza virus infection. Influenza type A virus was detected in 54 samples, which included 16 samples of A/H1N1/pdm09 subtype and 11 samples of A/H3N2/ subtype. The remaining 27 samples positive for influenza type A were not subtyped. Influenza type B virus was detected in 57 samples, which appeared to be the dominant strain in this study. Furthermore, several cases of concurrent infection with influenza type B virus and the A/H1N/pdm09 or A/H3N2/ subtype were observed.

Characteristics and practices of National Immunisation Technical Advisory Groups in Europe and potential for collaboration, April 2014.

In many countries, national vaccination recommendations are developed by independent expert committees, so-called national immunisation technical advisory groups (NITAG). Since the evaluation of vaccines is complex and resource-demanding, collaboration between NITAGs that evaluate the same vaccines could be beneficial. We conducted a cross-sectional survey among 30 European countries in February 2014, to explore basic characteristics and current practices of European NITAGs and identify potential modes and barriers for collaboration. Of 28 responding countries, 26 reported to have a NITAG or an equivalent expert group. Of these, 20 apply a systematic approach in the vaccine decision-making process, e.g. by considering criteria such as country-specific disease epidemiology, vaccine efficacy/effectiveness/safety, health economics, programme implementation/logistics or country-specific values/preferences. However, applied frameworks and extent of evidence review differ widely. The use of systematic reviews is required for 15 of 26 NITAGs, while results from transmission modelling and health economic evaluations are routinely considered by 18 and 20 of 26 NITAGs, respectively. Twenty-five countries saw potential for NITAG-collaboration, but most often named structural concerns, e.g. different NITAG structures or countries' healthcare systems. Our survey gathered information that can serve as an inventory on European NITAGs, allowing further exploration of options and structures for NITAG collaboration.

Incidence and factors predicting whooping cough due to parapertussis diagnosis among patients referred to general practitioners, Poland, 2009-2011.

Parapertussis leads to similar symptoms as pertussis, both being caused by bacteria from the genus Bordetella. Poland does not routinely diagnose nor conduct surveillance for parapertussis. We estimated parapertussis incidence and determined predictors of parapertussis diagnosis in the Polish population. Between July 2009 and April 2011, we conducted a prospective cohort study among patients attending 78 general practices. We included patients aged ≥ 3 years, with cough lasting >2 weeks, interviewed patients and collected a nasopharyngeal swab. We confirmed cases by real-time PCR. We estimated parapertussis incidence rates by dividing the number of cases by the summed person-time of observation in respective practices. We assessed predictors of PCR-confirmed parapertussis by comparing cases with patients testing negative. Using logistic regression, we calculated odds ratios (ORs) and 95% confidence intervals (95%CI). We identified 78 cases among 1,231 patients meeting inclusion criteria. The incidence rate was 39/100,000 person-years (95%CI 31-49). The highest rates (140/100,000; 95%CI 74-239), were among children 3-5 years of age and the lowest (24/100,000; 95%CI 13-40) among persons aged 20-39 years of age. Boys aged 3-5 years (7.1; 2.1-25.3) and women aged >40 years (4.1; 1.4-11.7) or living in crowded households (4.3; 1.4-12.9) or contacting persons with prolonged cough (2.3; 1.1-4.5) were more likely to be diagnosed. Our results suggest that laboratory diagnosis could be prioritized for children in the preschool age and women aged over 40 who were referred to their GP with prolonged cough. In the absence of vaccine, post-exposure prophylaxis for close contacts of parapertussis cases could an adequate preventative measure.

Influenza vaccine effectiveness estimates in Europe in a season with three influenza type/subtypes circulating: the I-MOVE multicentre case-control study, influenza season 2012/13.

In the fifth season of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE), we undertook a multicentre case-control study (MCCS) in seven European Union (EU) Member States to measure 2012/13 influenza vaccine effectiveness against medically attended influenza-like illness (ILI) laboratory confirmed as influenza. The season was characterised by substantial co-circulation of influenza B, A(H1N1)pdm09 and A(H3N2) viruses. Practitioners systematically selected ILI patients to swab ≤7 days of symptom onset. We compared influenza-positive by type/subtype to influenza-negative patients among those who met the EU ILI case definition. We conducted a complete case analysis using logistic regression with study as fixed effect and calculated adjusted vaccine effectiveness (AVE), controlling for potential confounders (age, sex, symptom onset week and presence of chronic conditions). We calculated AVE by type/subtype. Study sites sent 7,954 ILI/acute respiratory infection records for analysis. After applying exclusion criteria, we included 4,627 ILI patients in the analysis of VE against influenza B (1,937 cases), 3,516 for A(H1N1)pdm09 (1,068 cases) and 3,340 for influenza A(H3N2) (730 cases). AVE was 49.3% (95% confidence interval (CI): 32.4 to 62.0) against influenza B, 50.4% (95% CI: 28.4 to 65.6) against A(H1N1)pdm09 and 42.2% (95% CI: 14.9 to 60.7) against A(H3N2). Our results suggest an overall low to moderate AVE against influenza B, A(H1N1)pdm09 and A(H3N2), between 42 and 50%. In this season with many co-circulating viruses, the high sample size enabled stratified AVE by type/subtype. The low estimates indicate seasonal influenza vaccines should be improved to achieve acceptable protection levels.

Incidence of pertussis in patients of general practitioners in Poland.

We estimated the incidence of pertussis in patients consulting general practitioners (GPs). Between July 2009 and April 2011, we conducted a prospective cohort study of patients attending 78 general practices (158 863 persons overall). We included patients aged ≥ 3 years, with cough lasting 2-15 weeks, who gave informed consent. GPs interviewed eligible patients, collected a blood specimen, and a nasopharyngeal swab. At follow-up 30-60 days after the initial visit, physicians collected a second blood specimen and conducted patient interview. Cases were confirmed by specific IgA and/or IgG antibody titre exceeding significantly the general population background level or detection of bacterial DNA by real-time PCR. During the study period, 3864 patients with prolonged cough consulted the participating GPs, of those 1852 met the inclusion criteria, 1232 were recruited, and 288 were confirmed as pertussis cases (4% by PCR, 96% by serology). The adjusted incidence rate was 201.1/100 000 person-years [95% confidence interval (CI) 133.9-302.0], ranging from 456.5 (95% CI 239.3-870.8) in the 15-19 years group to 94.0 (95% CI 33.4-264.5) in the 25-29 years group. The reporting ratio was 61, ranging from 4 in those aged 3-5 years, to 167 in those aged 65-69 years. The study confirmed high incidence of pertussis in all age groups in the general population, in particular in adults, not appropriately documented by the existing surveillance system.

Low and decreasing vaccine effectiveness against influenza A(H3) in 2011/12 among vaccination target groups in Europe: results from the I-MOVE multicentre case-control study.

Within the Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) project we conducted a multicentre case­control study in eight European Union (EU) Member States to estimate the 2011/12 influenza vaccine effectiveness against medically attended influenza-like illness (ILI) laboratory-confirmed as influenza A(H3) among the vaccination target groups. Practitioners systematically selected ILI / acute respiratory infection patients to swab within seven days of symptom onset. We restricted the study population to those meeting the EU ILI case definition and compared influenza A(H3) positive to influenza laboratory-negative patients. We used logistic regression with study site as fixed effect and calculated adjusted influenza vaccine effectiveness (IVE), controlling for potential confounders (age group, sex, month of symptom onset, chronic diseases and related hospitalisations, number of practitioner visits in the previous year). Adjusted IVE was 25% (95% confidence intervals (CI): -6 to 47) among all ages (n=1,014), 63% (95% CI: 26 to 82) in adults aged between 15 and 59 years and 15% (95% CI: -33 to 46) among those aged 60 years and above. Adjusted IVE was 38% (95%CI: -8 to 65) in the early influenza season (up to week 6 of 2012) and -1% (95% CI: -60 to 37) in the late phase. The results suggested a low adjusted IVE in 2011/12. The lower IVE in the late season could be due to virus changes through the season or waning immunity. Virological surveillance should be enhanced to quantify change over time and understand its relation with duration of immunological protection. Seasonal influenza vaccines should be improved to achieve acceptable levels of protection.