Clinical influenza activity in Europe is still low, with influenza B virus being dominant: an update from EISS

Influenza activity in Europe during the winter 2005-2006 started late January - early February 2006 and first occurred in the Netherlands, France, Greece and England. Subsequently, countries were affected in a random pattern across Europe and the period of influenza activity lasted till the end of April. In contrast to the winter seasons in the period 2001-2005, no west-east pattern was detected. In 12 out of 23 countries, the consultation rates for influenza-like illness or acute respiratory infection in the winter 2005-2006 were similar or higher than in the winter 2004-2005, despite a dominance of influenza B viruses that normally cause milder disease than influenza A viruses. In the remaining 11 countries the consultation rates were lower to much lower than in the winter 2004-2005. The highest consultation rates were usually observed among children aged 0-14. The circulating influenza virus types and subtypes were distributed heterogeneously across Europe. Although the figures for total virus detections in Europe indicated a predominance of influenza B virus (58% of all virus detections), in many countries influenza B virus was predominant only early in the winter, whilst later there was a marked increase in influenza A virus detections. Among the countries where influenza A viruses were co-dominant with B viruses (9/29) or were predominant (4/29), the dominant influenza A subtype was H3 in seven countries and H1 in four countries. The vast majority of characterised influenza B viruses (90%) were similar to the B/Victoria/2/87 lineage of influenza B viruses that re-emerged in Europe in the winter 2004-2005 but were not included in the vaccine for the influenza season 2005-2006. This might help to explain the dominance of influenza B viruses in many countries in Europe during the winter 2005-2006. The influenza A(H3) and A(H1) viruses were similar to the reference strains included in the 2005-2006 vaccine, A/California/7/2004 (H3N2) and A/New Caledonia/20/99 (H1N1), respectively. In conclusion, the 2005-2006 influenza epidemic in Europe was characterised by moderate clinical activity, a heterogeneous spread pattern across Europe, and a variable virus dominance by country, although an overall dominance of influenza B viruses that did not match the virus strain included in the vaccine was observed.

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Seasonal influenza activity in Europe: Declining in most countries in the West but increasing in the North-East

Weekly releases (1997–2007) ◽

10.2807/esw.12.10.03152-en ◽

2007 ◽

Vol 12 (10) ◽

Cited By ~ 1

Author(s):

J MS Arkema ◽

T J Meerhoff ◽

W J Paget ◽

A Meijer ◽

F Ansaldi ◽

...

Keyword(s):

Respiratory Infection ◽

Acute Respiratory Infection ◽

Seasonal Influenza ◽

The West ◽

Influenza Like Illness ◽

North East ◽

The North ◽

Influenza Activity

This winter, the consultation rates for influenza like illness (ILI) and/or acute respiratory infection (ARI) started to increase firstly in Scotland, Greece and Spain in December 2006 [1], where they have already returned to levels just above or at the baseline.

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Outbreaks of influenza and influenza-like illness in schools in England and Wales, 2005/06

Eurosurveillance ◽

10.2807/esm.12.05.00705-en ◽

2007 ◽

Vol 12 (5) ◽

pp. 3-4 ◽

Cited By ~ 11

Author(s):

H Zhao ◽

C A Joseph ◽

N Phin

Keyword(s):

Primary Schools ◽

Large Scale ◽

Health Protection ◽

Influenza B Virus ◽

Influenza B ◽

Base Line ◽

Local Health ◽

England And Wales ◽

Influenza Like Illness ◽

Influenza Activity

In England and Wales, clinical reports from primary care showed that influenza activity for the season 2005/06 only rose above the base line for four weeks during February 2006. However, outbreaks of influenza-like illness and/or gastrointestinal infection in schools began to be reported to the Health Protection Agency, Centre for Infections in early January 2006. To quantify the type, size and the spread of these outbreaks a reporting form was distributed to local Health Protection Units in England and to Wales for retrospective and prospective weekly completion. Between weeks 48/05 and 11/06, a total of 688 school outbreaks were reported, including 658 outbreaks of influenza-like illness with or without other symptoms. The remaining 30 outbreaks listed as gastrointestinal only were excluded from the present analysis. Influenza B was confirmed in 70 outbreaks where testing took place. 61% of the outbreaks were reported from primary schools for children aged 4-11 years. This large scale outbreak in school children with flu-like illness across England and Wales was not picked up by most of the routine surveillance schemes, therefore, we believe that a school absentee monitoring and reporting system may be needed to give an early warning of increased influenza activity, especially for the mild form of the disease caused by influenza B virus

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Common variable hypogammaglobulinemia and severe respiratory infection by influenza B virus in pediatric patient

Journal of Allergy and Clinical Immunology ◽

10.1016/s0091-6749(02)81725-0 ◽

2002 ◽

Vol 109 (1) ◽

pp. S197-S197 ◽

Cited By ~ 1

Author(s):

Cristina Jacob ◽

Angela Fomin ◽

Ana Paula Castro ◽

Renata Santoro ◽

Jacques Sztajnbok ◽

...

Keyword(s):

Pediatric Patient ◽

Respiratory Infection ◽

Influenza B Virus ◽

Influenza B ◽

B Virus ◽

Severe Respiratory Infection ◽

Common Variable

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Influenza Surveillance Among Children With Pneumonia Admitted to a District Hospital in Coastal Kenya, 2007–2010

The Journal of Infectious Diseases ◽

10.1093/infdis/jis536 ◽

2012 ◽

Vol 206 (suppl_1) ◽

pp. S61-S67 ◽

Cited By ~ 18

Author(s):

Clayton O. Onyango ◽

Regina Njeru ◽

Sidi Kazungu ◽

Rachel Achilla ◽

Wallace Bulimo ◽

...

Keyword(s):

Virus Infection ◽

Influenza A Virus ◽

Respiratory Infection ◽

Acute Respiratory Infection ◽

Influenza A ◽

District Hospital ◽

Severe Pneumonia ◽

Influenza B Virus ◽

Influenza B ◽

Virus Subtype

Abstract Background Influenza data gaps in sub-Saharan Africa include incidence, case fatality, seasonal patterns, and associations with prevalent disorders. Methods Nasopharyngeal samples from children aged <12 years who were admitted to Kilifi District Hospital during 2007–2010 with severe or very severe pneumonia and resided in the local demographic surveillance system were screened for influenza A, B, and C viruses by molecular methods. Outpatient children provided comparative data. Results Of 2002 admissions, influenza A virus infection was diagnosed in 3.5% (71), influenza B virus infection, in 0.9% (19); and influenza C virus infection, in 0.8% (11 of 1404 tested). Four patients with influenza died. Among outpatients, 13 of 331 (3.9%) with acute respiratory infection and 1 of 196 without acute respiratory infection were influenza positive. The annual incidence of severe or very severe pneumonia, of influenza (any type), and of influenza A, was 1321, 60, and 43 cases per 100 000 <5 years of age, respectively. Peak occurrence was in quarters 3–4 each year, and approximately 50% of cases involved infants: temporal association with bacteremia was absent. Hypoxia was more frequent among pneumonia cases involving influenza (odds ratio, 1.78; 95% confidence interval, 1.04–1.96). Influenza A virus subtypes were seasonal H3N2 (57%), seasonal H1N1 (12%), and 2009 pandemic H1N1 (7%). Conclusions The burden of influenza was small during 2007–2010 in this pediatric hospital in Kenya. Influenza A virus subtype H3N2 predominated, and 2009 pandemic influenza A virus subtype H1N1 had little impact.

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Enhancement of the Influenza Surveillance System in the Russian Federation: the Main Results of the Sentinel Surveillance for Influenza and other Acute Respiratory Viral Infections

Epidemiology and Vaccinal Prevention ◽

10.31631/2073-3046-2017-16-1-7-15 ◽

2017 ◽

Vol 16 (1) ◽

pp. 7-15 ◽

Cited By ~ 2

Author(s):

A. A. Sominina ◽

E. A. Smorodintseva ◽

K. A. Stolyarov ◽

A. A. Mel'nikova

Keyword(s):

Respiratory Infection ◽

Surveillance System ◽

Acute Respiratory Infection ◽

Influenza A ◽

Hospitalized Patients ◽

Sentinel Surveillance ◽

Influenza Surveillance ◽

Influenza B Virus ◽

Influenza B ◽

Influenza A H1n1

Existing influenza surveillance system is constantly improved to obtain comprehensive information for understanding of continuously changing situation with the influenza, which is a consequence of the highest variability of the pathogen, its ability to reassortment and the imminence of emergence a new shift-variants of the virus that could cause the next pandemic events. For this purpose, since the 2010 - 2011 epidemic season, in addition to the traditional surveillance system (TS) a new well standardized sentinel surveillance system (SS) for rapid clinical and epidemiological data obtaining was introduced in Russia. A total 7812 hospitalized patients with severe acute respiratory infection (SARI) and 9854 outpatients with influenza-like illness and acute respiratory infection (ILI/ARI) were investigated during the 6-year period in SS. Percent of SARI among all hospitalized patients ranged from 1.7 to 3.1%; about 5.3 - 7.5% SARI patients were placed in the Intensive Care Unit. Etiological monitoring using PCR showed influenza spread trends in SS similar to those registered in the TS: a clear predominance of influenza A (H1N1) pdm09 among SARI and ILI/ARI in 2010 - 2011 and 2015 - 2016 epidemic seasons, influenza A (H3N2) in the epidemic seasons 2011 - 2012 and 2014 - 2015, the co-circulation of these pathogens in 2012 - 2013, 2013 - 2014 seasons in Russia. SARI caused by influenza B virus were detected less frequently than influenza A but increased influenza B activity was registered in the epidemic of 2014 -2015, when Yamagata lineage changed suddenly for the Victorian one. The average frequency of influenza diagnosis among SARI between the seasons varied in the range 12.5 - 27.1%, at the peak of the epidemic it reached 44.8 - 73.5% and was the highest during the season with active circulation of influenza A (H1N1) pdm09 virus. The rate of influenza diagnosis among ILI/ARI has always been lower than that among SARI. Studies have also shown the importance of rhinovirus, RS-virus and parainfluenza infections in SARI development. The frequency of registration of coronaviruses, metapneumovirus and bocavirus infection was very low in SARI and ILI/ARI. It was found that in all studied seasons most of SARI patients with influenza have not been vaccinated. Among ILI/ARI outpatients with influenza, the frequency of vaccinated individuals for the entire period of the study was estimated as 10.1%, which was 4.2 times higher than that in SARI, where only 2.4% of patients were vaccinated. In addition, it was found that for all six seasons the SARI patients with influenza were treated with antivirals drugs 2 times less often compared to outpatients. Analysis of data on concomitant diseases and conditions in SARI patients with influenza confirmed the leading role of pregnancy as a risk factor for hospitalization in all influenza epidemics, irrespective of their etiology. In addition, diabetes and cardiovascular disease were recognized as risk factors for influenza associated SARI development.

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Epidemiological and clinical features of acute respiratory infections occurring in St. Petersburg during the 2017–2018 and 2018–2019 epidemic seasons

Journal Infectology ◽

10.22625/2072-6732-2021-13-2-53-60 ◽

2021 ◽

Vol 13 (2) ◽

pp. 53-60

Author(s):

D. A. Guzhov ◽

E. A. Elpaeva ◽

M. A. Egorova ◽

V. A. Eder ◽

I. L. Baranovskya ◽

...

Keyword(s):

Clinical Features ◽

Respiratory Infection ◽

Acute Respiratory Infection ◽

Influenza A ◽

Bacterial Infections ◽

Respiratory Infections ◽

Influenza B Virus ◽

Influenza B ◽

Acute Respiratory Infections ◽

Pharyngeal Wall

Objective: to analyze the epidemiological and clinical features of acute respiratory infections occurring during the St. Petersburg 2017-2018 and 2018-2019 epidemic seasons.Materials and methods: the study included 457 patients, treated in St. Petersburg clinics from 2017-2019, displaying symptoms of acute respiratory infection (ARI), including evaluation of their clinical histories. Pathogen types were determined by polymerase chain reaction (PCR). Data analysis was carried out using mathematical statistics methods using the Statistica 10 software package (StatSoft Inc.).Results: in this study, we examined the epidemiological and clinical features of acute respiratory infections in St. Petersburg occurring during two epidemic seasons, 2017-2018 and 2018-2019. The 2017-2018 season was characterized by a prevalence of infections caused by influenza B viruses and influenza A subtype H3N2 viruses. In the 2018-2019 season, there was a greater number of acute respiratory viral infections (ARVIs) and infections caused by influenza A subtype H1N1pdm; influenza B virus was detected only in isolated cases. In the 2017-2018 sore throats and muscle aches were a characteristic symptom of influenza A H1N1pdm infections, of bacterial infections – only sore throats. It was shown that throat pain and vasodilation of the scleral and soft palate vessels were significantly more frequent in the 2017-2018 season, compared to the 2018-2019 season. Cough and redness of the posterior pharyngeal wall were hallmark signs of ARVIs in the 2018-2019 season.Conclusion: according to the data, each epidemic season is characterized not only by its own type-specific acute respiratory infection frequencies, but also by different clinical manifestation frequencies. For global monitoring, treatment effectiveness evaluation, and refined study of acute respiratory infection clinical features, it is advisable to use approaches which incorporate accurate, specific, and rapid molecular biological methods capable of identifying a broad range of pathogens.

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Epidemiological and clinical features of acute respiratory infections occurring in St. Petersburg during the 2017–2018 and 2018–2019 epidemic seasons

Journal Infectology ◽

10.22625/2072-6732-2020-12-4-65-71 ◽

2020 ◽

Vol 12 (4) ◽

pp. 65-71

Author(s):

D. A. Guzhov ◽

E. A. Elpaeva ◽

M. A. Egorova ◽

V. A. Eder ◽

I. L. Baranovskaya ◽

...

Keyword(s):

Clinical Features ◽

Respiratory Infection ◽

Acute Respiratory Infection ◽

Influenza A ◽

Bacterial Infections ◽

Respiratory Infections ◽

Influenza B Virus ◽

Influenza B ◽

Acute Respiratory Infections ◽

Pharyngeal Wall

Objective: to analyze the epidemiological and clinical features of acute respiratory infections occurring during the St. Petersburg 2017–2018 and 2018–2019 epidemic seasons.Materials and methods: the study included 457 patients, treated in St. Petersburg clinics from 2017–2019, displaying symptoms of acute respiratory infection (ARI), including evaluation of their clinical histories. Pathogen types were determined by polymerase chain reaction (PCR). Data analysis was carried out using mathematical statistics methods using the Statistica 10 software package (StatSoft Inc.).Results: in this study, we examined the epidemiological and clinical features of acute respiratory infections in St. Petersburg occurring during two epidemic seasons, 2017–2018 and 2018–2019. The 2017–2018 season was characterized by a prevalence of infections caused by influenza B viruses and influenza A subtype H3N2 viruses. In the 2018–2019 season, there was a greater number of acute respiratory viral infections (ARVIs) and infections caused by influenza A subtype H1N1pdm; influenza B virus was detected only in isolated cases. In the 2017–2018 sore throats and muscle aches were a characteristic symptom of influenza A H1N1pdm infections, of bacterial infections – only sore throats. It was shown that throat pain and vasodilation of the scleral and soft palate vessels were significantly more frequent in the 2017–2018 season, compared to the 2018–2019 season. Cough and redness of the posterior pharyngeal wall were hallmark signs of ARVIs in the 2018–2019 season.Conclusion: according to the data, each epidemic season is characterized not only by its own type-specific acute respiratory infection frequencies, but also by different clinical manifestation frequencies. For global monitoring, treatment effectiveness evaluation, and refined study of acute respiratory infection clinical features, it is advisable to use approaches which incorporate accurate, specific, and rapid molecular biological methods capable of identifying a broad range of pathogens.

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Mild to moderate influenza activity in Europe and the detection of novel A(H1N2) and B viruses during the winter of 2001-02

Eurosurveillance ◽

10.2807/esm.07.11.00373-en ◽

2002 ◽

Vol 7 (11) ◽

pp. 147-157 ◽

Cited By ~ 15

Author(s):

W J Paget ◽

T J Meerhoff ◽

N L Goddard ◽

Keyword(s):

The Netherlands ◽

Influenza A ◽

Historical Data ◽

Influenza B Virus ◽

Influenza B ◽

The United Kingdom ◽

H1n2 Virus ◽

B Virus ◽

Influenza Activity ◽

Virus Strains

Influenza activity in Europe during the 2001-02 influenza season was mild to moderate. Compared to historical data, the intensity was low in six countries, medium in eleven and high in one country (Spain). The dominant virus circulating in Europe was influenza A(H3N2). Two novel influenza virus strains were isolated during the 2001-02 season: influenza A(H1N2) viruses (mainly isolated in the United Kingdom and Ireland, but also in Belgium, France, Germany, the Netherlands, Portugal, Sweden, Switzerland and Romania), and influenza B viruses belonging to the B/Victoria/2/87 lineage (mainly isolated in Germany, but also sporadically in France, Italy, the Netherlands and Norway). With the exception of H1N2 virus detections in England, and Ireland and the influenza B viruses belonging to the B/Victoria/2/87 lineage in Germany, these two viruses did not circulate widely in Europe and did not play an important role in influenza activity during the 2001-02 season. An influenza B virus belonging to the B/Victoria/2/87 lineage will be included in the 2002-03 influenza vaccine. The new subtype influenza A(H1N2) is covered by the 2002-03 vaccine, as the haemagglutinin and neuraminidase components of the H1N2 viruses are antigenically similar to the vaccine components (H1N1 and H3N2).

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Effects of Absolute Humidity, Relative Humidity, Temperature, and Wind Speed on Influenza Activity in Toronto, Ontario, Canada

Applied and Environmental Microbiology ◽

10.1128/aem.02426-18 ◽

2019 ◽

Vol 85 (6) ◽

Cited By ~ 26

Author(s):

Adriana Peci ◽

Anne-Luise Winter ◽

Ye Li ◽

Saravanamuttu Gnaneshan ◽

Juan Liu ◽

...

Keyword(s):

Influenza Virus ◽

Relative Humidity ◽

Influenza A ◽

Absolute Humidity ◽

Influenza B Virus ◽

Influenza B ◽

Virus Infections ◽

B Virus ◽

Influenza Activity ◽

Temperate Climates

ABSTRACT The occurrence of influenza in different climates has been shown to be associated with multiple meteorological factors. The incidence of influenza has been reported to increase during rainy seasons in tropical climates and during the dry, cold months of winter in temperate climates. This study was designed to explore the role of absolute humidity (AH), relative humidity (RH), temperature, and wind speed (WS) on influenza activity in the Toronto, ON, Canada, area. Environmental data obtained from four meteorological stations in the Toronto area over the period from 1 January 2010 to 31 December 2015 were linked to patient influenza data obtained for the same locality and period. Data were analyzed using correlation, negative binomial regressions with linear predictors, and splines to capture the nonlinear relationship between exposure and outcomes. Our study found a negative association of both AH and temperature with influenza A and B virus infections. The effect of RH on influenza A and B viruses was controversial. Temperature fluctuation was associated with increased numbers of influenza B virus infections. Influenza virus was less likely to be detected from community patients than from patients tested as part of an institutional outbreak investigation. This could be more indicative of nosocomial transmission rather than climactic factors. The nonlinear nature of the relationship of influenza A virus with temperature and of influenza B virus with AH, RH, and temperature could explain the complexity and variation between influenza A and B virus infections. Predicting influenza activity is important for the timing of implementation of disease prevention and control measures as well as for resource allocation. IMPORTANCE This study examined the relationship between environmental factors and the occurrence of influenza in general. Since the seasonality of influenza A and B viruses is different in most temperate climates, we also examined each influenza virus separately. This study reports a negative association of both absolute humidity and temperature with influenza A and B viruses and tries to understand the controversial effect of RH on influenza A and B viruses. This study reports a nonlinear relation between influenza A and B viruses with temperature and influenza B virus with absolute and relative humidity. The nonlinear nature of these relations could explain the complexity and difference in seasonality between influenza A and B viruses, with the latter predominating later in the season. Separating community-based specimens from those obtained during outbreaks was also a novel approach in this research. These findings provide a further understanding of influenza virus transmission in temperate climates.

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