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Antonelli-Incalzi R, Blasi F, Conversano M, Gabutti G, Giuffrida S, Maggi S, Marano C, Rossi A, Vicentini M. Manifesto on the Value of Adult Immunization: "We Know, We Intend, We Advocate". Vaccines (Basel) 2021; 9:vaccines9111232. [PMID: 34835163 PMCID: PMC8625332 DOI: 10.3390/vaccines9111232] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 12/11/2022] Open
Abstract
Immunization through vaccination is a milestone achievement that has made a tremendous contribution to public health. Historically, immunization programs aimed firstly to protect children, who were disproportionally affected by infectious diseases. However, vaccine-preventable diseases can have significant impacts on adult mortality, health, and quality of life. Despite this, adult vaccinations have historically been overlooked in favor of other health priorities, because their benefits to society were not well recognized. As the general population is aging, the issue of vaccination in older adults is gaining importance. In high-income countries, recommendations for the routine vaccination of older adults have been gradually introduced. The Italian National Immunization Plan is considered to be among the most advanced adult vaccination plans in Europe. However, available data indicate there is low adherence to vaccination recommendations in Italy. The COVID-19 pandemic has exposed the damage that can be caused by an infectious disease, especially among adults and individuals with comorbidities. The aim of this “Manifesto”, therefore, is to provide an overview of the existing evidence on the value of adult vaccination, in the Italian context, with a call to action to healthcare providers and health authorities.
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Affiliation(s)
- Raffaele Antonelli-Incalzi
- Geriatric Unit, Campus Bio-Medico University, 00128 Rome, Italy;
- Italian Society of Gerontology and Geriatrics, 50129 Florence, Italy
| | - Francesco Blasi
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy;
- Respiratory Unit and Adult Cystic Fibrosis Center, Department of Internal Medicine, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Michele Conversano
- Department for Public Health, Local Health Unit Taranto, 74121 Taranto, Italy;
| | - Giovanni Gabutti
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy;
| | - Sandro Giuffrida
- Department of Prevention, Local Health Unit Reggio Calabria, 89124 Reggio Calabria, Italy;
| | - Stefania Maggi
- Aging Branch, Institute of Neuroscience, National Research Council, 35128 Padova, Italy;
| | | | - Alessandro Rossi
- Italian Society of General Medicine and Primary Care, 50142 Florence, Italy;
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Li J, Wang C, Ruan L, Jin S, Ye C, Yu H, Zhu W, Wang X. Development of influenza-associated disease burden pyramid in Shanghai, China, 2010-2017: a Bayesian modelling study. BMJ Open 2021; 11:e047526. [PMID: 34497077 PMCID: PMC8438833 DOI: 10.1136/bmjopen-2020-047526] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVES Negative estimates can be produced when statistical modelling techniques are applied to estimate morbidity and mortality attributable to influenza. Based on the prior knowledge that influenza viruses are hazardous pathogens and have adverse health outcomes of respiratory and circulatory disease (R&C), we developed an improved model incorporating Bayes' theorem to estimate the disease burden of influenza in Shanghai, China, from 2010 to 2017. DESIGN A modelling study using aggregated data from administrative systems on weekly R&C mortality and hospitalisation, influenza surveillance and meteorological data. We constrained the regression coefficients for influenza activity to be positive by truncating the prior distributions at zero. SETTING Shanghai, China. PARTICIPANTS People registered with R&C deaths (450 298) and hospitalisations (2621 787, from 1 July 2013), and with influenza-like illness (ILI) outpatient visits (342 149) between 4 January 2010 and 31 December 2017. PRIMARY OUTCOME MEASURES Influenza-associated disease burden (mortality, hospitalisation and outpatient visit rates) and clinical severity (outpatient-mortality, outpatient-hospitalisation and hospitalisation-mortality risks). RESULTS Influenza was associated with an annual average of 15.49 (95% credibility interval (CrI) 9.06-22.06) excess R&C deaths, 100.65 (95% CrI 48.79-156.78) excess R&C hospitalisations and 914.95 (95% CrI 798.51-1023.66) excess ILI outpatient visits per 100 000 population in Shanghai. 97.23% and 80.24% excess R&C deaths and hospitalisations occurred in people aged ≥65 years. More than half of excess morbidity and mortality were associated with influenza A(H3N2) virus, and its severities were 1.65-fold to 3.54-fold and 1.47-fold to 2.16-fold higher than that for influenza A(H1N1) and B viruses, respectively. CONCLUSIONS The proposed Bayesian approach with reasonable prior information improved estimates of influenza-associated disease burden. Influenza A(H3N2) virus was generally associated with higher morbidity and mortality, and was relatively more severe compared with influenza A(H1N1) and B viruses. Targeted influenza prevention and control strategies for the elderly in Shanghai may substantially reduce the disease burden.
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Affiliation(s)
- Jing Li
- School of Public Health, Fudan University, Shanghai, Shanghai, China
- Renal Division, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China
- Clinical Research Academy, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China
| | - Chunfang Wang
- Department of Vital Statistics, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China
| | - Luanqi Ruan
- Research Base of Key Laboratory of Surveillance and Early Warning on Infectious Disease, Pudong New Area Center for Disease Control and Prevention, Shanghai, China
| | - Shan Jin
- Department of Vital Statistics, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China
| | - Chuchu Ye
- Research Base of Key Laboratory of Surveillance and Early Warning on Infectious Disease, Pudong New Area Center for Disease Control and Prevention, Shanghai, China
| | - Huiting Yu
- Department of Vital Statistics, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China
| | - Weiping Zhu
- Research Base of Key Laboratory of Surveillance and Early Warning on Infectious Disease, Pudong New Area Center for Disease Control and Prevention, Shanghai, China
| | - Xiling Wang
- School of Public Health, Fudan University, Shanghai, Shanghai, China
- Shanghai Key Laboratory of Meteorology and Health, Shanghai, China
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Chen LJ, Guo JJ, Guo WW, Shen EX, Wang X, Li KJ, Yan J, Shi M, Li YR, Hou W. Molecular Epidemiology and Vaccine Compatibility Analysis of Seasonal Influenza Viruses in Wuhan, 2016-2019. Virol Sin 2020; 35:556-565. [PMID: 32394327 DOI: 10.1007/s12250-020-00225-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 03/07/2020] [Indexed: 10/24/2022] Open
Abstract
Influenza viruses (FLUV) cause high morbidity and mortality annually in the world and pose a serious threat to the public health. Wuhan, as an important transportation hub in China, has a dense population and suitable climate, which also lays a major hidden danger for the outbreak of influenza. To survey and characterize the seasonal FLUV in Wuhan during 2016-2019, we collected 44,738 throat swabs, among which 15.5% were influenza A (FLUAV) positive, 6.1% influenza B (FLUBV) and 0.3% co-infection. By monitoring FLUV in each month from June 2016 to May 2019, different with the previously seasonality pattern, only a single influenza peak was appeared in winter of 2017-2018 and 2018-2019, respectively. These data indicated that the complex circulation pattern of seasonal influenza in Wuhan. In addition, we found the age group was skewed towards 5-14 years group whose activity were mostly school based, which suggested school may be an important place for influenza outbreaks. Meanwhile, phylogenic analysis revealed that two subtypes (subclade 3C.2a2 and 3C.2a1b) of A(H3N2) were circulating in Wuhan and there was an obvious transition in 2018 because the two subclades were detected simultaneously. Furthermore, by estimating the vaccine effectiveness, we found that the vaccine strain of FLUAV didn't seem to match very well the current epidemic strain, especially A(H3N2). Hence, more accurate prediction of seasonal outbreak is essential for vaccine design. Taken together, our results provided the current information about seasonal FLUV in Wuhan which form the basis for vaccine updating.
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Affiliation(s)
- Liang-Jun Chen
- Department of Laboratory Medicine, Zhongnan Hospital, State Key Laboratory of Virology, Institute of Medical Virology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Jing-Jing Guo
- Department of Laboratory Medicine, Zhongnan Hospital, State Key Laboratory of Virology, Institute of Medical Virology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Wei-Wei Guo
- Department of Laboratory Medicine, Zhongnan Hospital, State Key Laboratory of Virology, Institute of Medical Virology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - E-Xiang Shen
- Department of Laboratory Medicine, Zhongnan Hospital, State Key Laboratory of Virology, Institute of Medical Virology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Xin Wang
- Department of Laboratory Medicine, Zhongnan Hospital, State Key Laboratory of Virology, Institute of Medical Virology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Kai-Ji Li
- Department of Laboratory Medicine, Zhongnan Hospital, State Key Laboratory of Virology, Institute of Medical Virology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Jie Yan
- Department of Laboratory Medicine, Zhongnan Hospital, State Key Laboratory of Virology, Institute of Medical Virology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Mang Shi
- School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Marie Bashir Institute for Infectious Diseases and Biosecurity, Charles Perkins Centre, School of Biological Sciences and Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Yi-Rong Li
- Department of Laboratory Medicine, Zhongnan Hospital, State Key Laboratory of Virology, Institute of Medical Virology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China.
| | - Wei Hou
- Department of Laboratory Medicine, Zhongnan Hospital, State Key Laboratory of Virology, Institute of Medical Virology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China.
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Abhimanyu, Coussens AK. The role of UV radiation and vitamin D in the seasonality and outcomes of infectious disease. Photochem Photobiol Sci 2018; 16:314-338. [PMID: 28078341 DOI: 10.1039/c6pp00355a] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The seasonality of infectious disease outbreaks suggests that environmental conditions have a significant effect on disease risk. One of the major environmental factors that can affect this is solar radiation, primarily acting through ultraviolet radiation (UVR), and its subsequent control of vitamin D production. Here we show how UVR and vitamin D, which are modified by latitude and season, can affect host and pathogen fitness and relate them to the outcomes of bacterial, viral and vector-borne infections. We conducted a thorough comparison of the molecular and cellular mechanisms of action of UVR and vitamin D on pathogen fitness and host immunity and related these to the effects observed in animal models and clinical trials to understand their independent and complementary effects on infectious disease outcome. UVR and vitamin D share common pathways of innate immune activation primarily via antimicrobial peptide production, and adaptive immune suppression. Whilst UVR can induce vitamin D-independent effects in the skin, such as the generation of photoproducts activating interferon signaling, vitamin D has a larger systemic effect due to its autocrine and paracrine modulation of cellular responses in a range of tissues. However, the seasonal patterns in infectious disease prevalence are not solely driven by variation in UVR and vitamin D levels across latitudes. Vector-borne pathogens show a strong seasonality of infection correlated to climatic conditions favoring their replication. Conversely, pathogens, such as influenza A virus, Mycobacterium tuberculosis and human immunodeficiency virus type 1, have strong evidence to support their interaction with vitamin D. Thus, UVR has both vitamin D-dependent and independent effects on infectious diseases; these effects vary depending on the pathogen of interest and the effects can be complementary or antagonistic.
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Affiliation(s)
- Abhimanyu
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Anzio Rd, Observatory, 7925, Western Cape, South Africa.
| | - Anna K Coussens
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Anzio Rd, Observatory, 7925, Western Cape, South Africa. and Division of Medical Microbiology, Department of Pathology, University of Cape Town, Anzio Rd, Observatory, 7925, Western Cape, South Africa
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Li L, Wong JY, Wu P, Bond HS, Lau EHY, Sullivan SG, Cowling BJ. Heterogeneity in Estimates of the Impact of Influenza on Population Mortality: A Systematic Review. Am J Epidemiol 2018; 187:378-388. [PMID: 28679157 PMCID: PMC5860627 DOI: 10.1093/aje/kwx270] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 06/22/2017] [Accepted: 06/27/2017] [Indexed: 12/15/2022] Open
Abstract
Influenza viruses are associated with a substantial global burden of morbidity and mortality every year. Estimates of influenza-associated mortality often vary between studies due to differences in study settings, methods, and measurement of outcomes. We reviewed 103 published articles assessing population-based influenza-associated mortality through searches of PubMed and Embase, and we identified considerable variation in the statistical methods used across studies. Studies using regression models with an influenza activity proxy applied 4 approaches to estimate influenza-associated mortality. The estimates increased with age and ranged widely, from -0.3-1.3 and 0.6-8.3 respiratory deaths per 100,000 population for children and adults, respectively, to 4-119 respiratory deaths per 100,000 population for older adults. Meta-regression analysis identified that study design features were associated with the observed variation in estimates. The estimates increased with broader cause-of-death classification and were higher for older adults than for children. The multiplier methods tended to produce lower estimates, while Serfling-type models were associated with higher estimates than other methods. No "average" estimate of excess mortality could reliably be made due to the substantial variability of the estimates, partially attributable to methodological differences in the studies. Standardization of methodology in estimation of influenza-associated mortality would permit improved comparisons in the future.
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Affiliation(s)
- Li Li
- WHO Collaborating Center for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China
- WHO Collaborating Center for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California
| | - Jessica Y Wong
- WHO Collaborating Center for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Peng Wu
- WHO Collaborating Center for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Helen S Bond
- WHO Collaborating Center for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Eric H Y Lau
- WHO Collaborating Center for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Sheena G Sullivan
- WHO Collaborating Center for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California
| | - Benjamin J Cowling
- WHO Collaborating Center for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China
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Narayan VV, Iuliano AD, Roguski K, Haldar P, Saha S, Sreenivas V, Kant S, Zodpey S, Pandav CS, Jain S, Krishnan A. Evaluation of data sources and approaches for estimation of influenza-associated mortality in India. Influenza Other Respir Viruses 2018; 12:72-80. [PMID: 29197173 PMCID: PMC5818338 DOI: 10.1111/irv.12493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2017] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND No estimates of influenza-associated mortality exist for India. OBJECTIVE To evaluate national mortality and viral surveillance data from India for assessing their appropriateness in estimating influenza-associated mortality using varied analytic approaches. METHODS We reviewed influenza virus surveillance data from a national influenza surveillance network. We also reviewed national mortality data from Civil Registration System (CRS), Medical Certification of Cause of Death (MCCD) and the Sample Registration System (SRS). We compared and scored the different sources of mortality data using specific criteria, including the process of cause of death assignment, sample size, proportion of ill-defined deaths, representativeness and availability of time series data. Each of these 5 parameters was scored on a scale from 1 to 5. To evaluate how to generate an influenza-associated mortality estimate for India, we also reviewed 4 methodologic approaches to assess the appropriateness of their assumptions and requirements for these data sets. RESULTS The influenza virus surveillance data included year-round sample testing for influenza virus and was found to be suitable for influenza mortality estimation modelling. Based on scoring for the 5 mortality data criteria, the SRS data had the highest score with 20 of 25 possible score, whereas MCCD and CRS scored 16 and 12, respectively. The SRS which used verbal autopsy survey methods was determined to be nationally representative and thus adequate for estimating influenza-associated mortality. Evaluation of the modelling methods demonstrated that Poisson regression, risk difference and mortality multiplier methods could be applied to the Indian setting. CONCLUSION Despite significant challenges, it is possible to estimate influenza-associated mortality in India.
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Affiliation(s)
| | | | | | - Partha Haldar
- Centre for Community MedicineAll India Institute of Medical SciencesNew DelhiIndia
| | | | | | - Shashi Kant
- Centre for Community MedicineAll India Institute of Medical SciencesNew DelhiIndia
| | | | | | - Seema Jain
- Centers for Disease Control and PreventionNew DelhiIndia
| | - Anand Krishnan
- Centre for Community MedicineAll India Institute of Medical SciencesNew DelhiIndia
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Nkwembe E, Cintron R, Sessions W, Kavunga H, Babakazo P, Manya L, Muyembe JJ. Molecular Analysis of Influenza A(H3N2) and A(H1N1)pdm09 Viruses circulating in the Democratic Republic of Congo, 2014. JOURNAL OF HARMONIZED RESEARCH IN MEDICAL AND HEALTH SCIENCES 2016; 3:247-264. [PMID: 29569652 PMCID: PMC5858567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
BACKGROUND Very little is known about influenza viruses circulating in the Democratic Republic of Congo (DRC). We aim to characterize genetically and antigenically Influenza A(H3N2) and A(H1N1)pdm09 viruses circulating in the country. METHODS From August to December 2014, specimens were collected from patients with influenza like-illness (ILI) or severe acute respiratory infection (SARI) in various surveillance sites. Specimens were tested using real time reverse transcription polymerase chain reaction (RT-PCR) method for the detection of influenza viruses. Positive influenza samples with a cycle threshold (Ct) <30 were genetically and antigenically characterized. RESULTS 32 samples tested were found positive to influenza A with Ct <30. At CDC Atlanta, 28 out of 32 samples (88%) were tested positive for influenza A virus, including 26 seasonal influenza A viruses subtype H3N2 and 2 pandemic influenza A viruses subtype H1N1pdm 2009. The majority of influenza A(H3N2) viruses were antigenically related to the A/Switzerland/9715293/2013 vaccine virus, while two influenza A(H1N1)pdm09 isolates were antigenically characterized as A/California/07/2009-like. All A(H3N2) and A(H1N1)pdm09 virus isolates characterized were sensitive to oseltamivir and zanamivir. CONCLUSION Two genetically distinct influenza subtypes were co-circulating in the DRCongo. Effective measures against influenza have been suggested.
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Affiliation(s)
| | - Roxana Cintron
- Influenza Division, Centers for Disease Control and Prevention,
Atlanta, USA
- Battelle Memorial Institute, TOPS Atlanta, USA
| | - Wendy Sessions
- Influenza Division, Centers for Disease Control and Prevention,
Atlanta, USA
| | - Hugo Kavunga
- Institut National de recherches Biomédicales, INRB
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8
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Acute Febrile Illness and Influenza Disease Burden in a Rural Cohort Dedicated to Malaria in Senegal, 2012-2013. PLoS One 2015; 10:e0143999. [PMID: 26679177 PMCID: PMC4682973 DOI: 10.1371/journal.pone.0143999] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 11/12/2015] [Indexed: 01/23/2023] Open
Abstract
Background African populations are considered to be particularly vulnerable to fever illnesses, including malaria, and acute respiratory disease, owing to limited resources and overcrowding. However, the overall burden of influenza in this context is poorly defined and incidence data for African countries are scarce. We therefore studied the fever syndrome incidence and more specifically influenza incidence in a cohort of inhabitants of Dielmo and Ndiop in Sokone district, Senegal. Methods Daily febrile-illness data were prospectively obtained from January 2012 to December 2013 from the cohort of the villages of Dielmo and Ndiop, initially dedicated to the study of malaria. Nasopharyngeal swabs were collected from, and malaria diagnosis tests (thick blood smears) carried out on, every febrile individual during clinical visits; reverse transcriptase-polymerase chain reaction was used to identify influenza viruses in the samples. Binomial negative regression analysis was used to study the relationship between the monthly incidence rate and various covariates. Results In Dielmo and Ndiop, the incidence of malaria has decreased, but fever syndromes remain frequent. Among the 1036 inhabitants included in the cohort, a total of 1,129 episodes of fever were reported. Influenza was present all year round with peaks in October-December 2012 and August 2013. The fever, ILI and influenza incidence density rates differed significantly between age groups. At both sites, the adjusted incidence relative risks for fever syndromes and ILI were significantly higher in the [6–24 months) than other age groups: 7.3 (95%CI: [5.7–9.3]) and 16.1 (95%CI: [11.1–23.3]) respectively. The adjusted incidence relative risk for influenza was significantly higher for the [0–6 months) than other age groups: 9.9 (95%CI: [2.9–33.6]). At both sites, incidence density rates were lowest among adults > = 50 years. Conclusions In this rural setting in Senegal, influenza was most frequent among the youngest children. Preventive strategies targeting this population should be implemented.
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Lambach P, Alvarez AMR, Hirve S, Ortiz JR, Hombach J, Verweij M, Hendriks J, Palkonyay L, Pfleiderer M. Considerations of strategies to provide influenza vaccine year round. Vaccine 2015; 33:6493-8. [PMID: 26319745 PMCID: PMC8218336 DOI: 10.1016/j.vaccine.2015.08.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 07/27/2015] [Accepted: 08/11/2015] [Indexed: 11/20/2022]
Abstract
There is potential for influenza vaccine programmes to make a substantial impact on severe disease in low-resource settings, however questions around vaccine composition and programmatic issues will require special attention. Some countries may benefit from immunization programmes that provide year-round supply of vaccine; however the best way to ensure adequate vaccine supply has yet to be determined. In this report, we discuss vaccine composition, availability, and programmatic issues that must be considered when developing year-round influenza immunization programmes. We then explore how these considerations have influenced immunization practices in the Latin American region as a case study. We identify three different approaches to achieve year-round supply: (1) alternating between Northern Hemisphere and Southern Hemisphere formulations, (2) extending the expiration date to permit extended use of a single hemisphere formulation, and (3) local vaccine manufacture with production timelines that align with local epidemiology. Each approach has its challenges and opportunities. The growing data suggesting high influenza disease burden in low resource countries underscores the compelling public health need to determine the best strategies for vaccine delivery.
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Affiliation(s)
- Philipp Lambach
- Initiative for Vaccine Research, World Health Organization, Geneva, Switzerland.
| | - Alba Maria Ropero Alvarez
- Immunization Unit, Pan American Health Organization, 525 Twenty Third St., NW, Washington, DC 20037, USA
| | | | - Justin R Ortiz
- Initiative for Vaccine Research, World Health Organization, Geneva, Switzerland
| | - Joachim Hombach
- Initiative for Vaccine Research, World Health Organization, Geneva, Switzerland
| | - Marcel Verweij
- Department of Social Sciences, Subdepartment Communication, Philosophy, and Technology, Wageningen University, Wageningen, The Netherlands
| | - Jan Hendriks
- Essential Medicines Department, World Health Organization, Geneva, Switzerland
| | - Laszlo Palkonyay
- Essential Medicines Department, World Health Organization, Geneva, Switzerland
| | - Michael Pfleiderer
- Federal Institute for Vaccines and Biomedicines, Paul-Ehrlich-Institut, Langen, Germany
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Abstract
Each year, influenza causes substantial mortality and morbidity worldwide. It is important to understand influenza in the tropics because of the significant burden in the region and its relevance to global influenza circulation. In this review, influenza burden, transmission dynamics, and their determinants in the tropics are discussed. Environmental, cultural, and social conditions in the tropics are very diverse and often differ from those of temperate regions. Theories that account for and predict influenza dynamics in temperate regions do not fully explain influenza epidemic patterns observed in the tropics. Routine surveillance and household studies have been useful in understanding influenza dynamics in the tropics, but these studies have been limited to only some regions; there is still a lack of information regarding influenza burden and transmission dynamics in many tropical countries. Further studies in the tropics will provide useful insight on many questions that remain.
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Affiliation(s)
- Sophia Ng
- Department of Epidemiology, School of Public Health, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109 USA
| | - Aubree Gordon
- Department of Epidemiology, School of Public Health, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109 USA
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Jennings LC. Influenza vaccines: an Asia-Pacific perspective. Influenza Other Respir Viruses 2014; 7 Suppl 3:44-51. [PMID: 24215381 DOI: 10.1111/irv.12180] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
This article provides an overview of some aspects of seasonal, pre-pandemic and pandemic influenza vaccines and initiatives aimed to increase influenza vaccine use within the Asia-Pacific region. Expanding the use of influenza vaccines in the Asia-Pacific region faces many challenges. Despite the recent regional history for the emergence of novel viruses, SARS, the H5N1 and H7N9, and the generation of and global seeding of seasonal influenza viruses and initiatives by WHO and other organisations to expand influenza awareness, the use of seasonal influenza vaccines remains low. The improvement in current vaccine technologies with the licensing of quadrivalent, live-attenuated, cell culture-based, adjuvanted and the first recombinant influenza vaccine is an important step. The development of novel influenza vaccines able to provide improved protection and with improved manufacturing capacity is also advancing rapidly. However, of ongoing concern are seasonal influenza impact and the low use of seasonal influenza vaccines in the Asia-Pacific region. Improved influenza control strategies and their implementation in the region are needed. Initiatives by the World Health Organization (WHO), and specifically the Western Pacific Regional Office of WHO, are focusing on consistent vaccine policies and guidelines in countries in the region. The Asian-Pacific Alliance for the Control of Influenza (APACI) is contributing through the coordination of influenza advocacy initiates.
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Affiliation(s)
- Lance C Jennings
- Microbiology Unit, Canterbury Health Laboratories, Christchurch, New Zealand; Department of Pathology, University of Otago, Christchurch, New Zealand
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12
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Yu H, Huang J, Huai Y, Guan X, Klena J, Liu S, Peng Y, Yang H, Luo J, Zheng J, Chen M, Peng Z, Xiang N, Huo X, Xiao L, Jiang H, Chen H, Zhang Y, Xing X, Xu Z, Feng Z, Zhan F, Yang W, Uyeki TM, Wang Y, Varma JK. The substantial hospitalization burden of influenza in central China: surveillance for severe, acute respiratory infection, and influenza viruses, 2010-2012. Influenza Other Respir Viruses 2014; 8:53-65. [PMID: 24209711 PMCID: PMC4177798 DOI: 10.1111/irv.12205] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2013] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Published data on influenza in severe acute respiratory infection (SARI) patients are limited. We conducted SARI surveillance in central China and estimated hospitalization rates of SARI attributable to influenza by viral type/subtype. METHODS Surveillance was conducted at four hospitals in Jingzhou, China from 2010 to 2012. We enrolled hospitalized patients who had temperature ≥37·3°C and at least one of: cough, sore throat, tachypnea, difficulty breathing, abnormal breath sounds on auscultation, sputum production, hemoptysis, chest pain, or chest radiograph consistent with pneumonia. A nasopharyngeal swab was collected from each case-patient within 24 hours of admission for influenza testing by real-time reverse transcription PCR. RESULTS Of 17 172 SARI patients enrolled, 90% were aged <15 years. The median duration of hospitalization was 5 days. Of 16 208 (94%) SARI cases tested, 2057 (13%) had confirmed influenza, including 1427 (69%) aged <5 years. Multiple peaks of influenza occurred during summer, winter, and spring months. Influenza was associated with an estimated 115 and 142 SARI hospitalizations per 100 000 during 2010-2011 and 2011-2012 [including A(H3N2): 55 and 44 SARI hospitalizations per 100 000; pandemic A(H1N1): 33 SARI hospitalizations per 100 000 during 2010-2011; influenza B: 26 and 98 hospitalizations per 100 000], with the highest rate among children aged 6-11 months (3603 and 3805 hospitalizations per 100 000 during 2010-2011 and 2011-2012, respectively). CONCLUSIONS In central China, influenza A and B caused a substantial number of hospitalizations during multiple periods each year. Our findings strongly suggest that young children should be the highest priority group for annual influenza vaccination in China.
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Affiliation(s)
- Hongjie Yu
- Divison of Infectious Disease, Chinese Center for Disease Control and PreventionBeijing, China
| | - Jigui Huang
- Jingzhou Center for Disease Control and PreventionJingzhou, China
| | - Yang Huai
- China-US Collaborative Program on Emerging and Re-emerging Infection Disease, US Centers for Disease Control and PreventionBeijing, China
| | - Xuhua Guan
- Hubei Provincial Centre for Disease Control and PreventionWuhan, China
| | - John Klena
- China-US Collaborative Program on Emerging and Re-emerging Infection Disease, US Centers for Disease Control and PreventionBeijing, China
| | - Shali Liu
- Jingzhou Central HospitalJingzhou, China
| | | | - Hui Yang
- Jingzhou Second People's HospitalJingzhou, China
| | - Jun Luo
- Jingzhou Maternal and Children's HospitalJingzhou, China
| | - Jiandong Zheng
- Divison of Infectious Disease, Chinese Center for Disease Control and PreventionBeijing, China
| | - Maoyi Chen
- Jingzhou Center for Disease Control and PreventionJingzhou, China
| | - Zhibin Peng
- Divison of Infectious Disease, Chinese Center for Disease Control and PreventionBeijing, China
| | - Nijuan Xiang
- Public Health Emergency Center, Chinese Center for Disease Control and PreventionBeijing, China
| | - Xixiang Huo
- Hubei Provincial Centre for Disease Control and PreventionWuhan, China
| | - Lin Xiao
- Jingzhou Center for Disease Control and PreventionJingzhou, China
| | - Hui Jiang
- Divison of Infectious Disease, Chinese Center for Disease Control and PreventionBeijing, China
| | - Hui Chen
- Hubei Provincial Centre for Disease Control and PreventionWuhan, China
| | - Yuzhi Zhang
- China-US Collaborative Program on Emerging and Re-emerging Infection Disease, US Centers for Disease Control and PreventionBeijing, China
| | - Xuesen Xing
- Hubei Provincial Centre for Disease Control and PreventionWuhan, China
| | - Zhen Xu
- Divison of Infectious Disease, Chinese Center for Disease Control and PreventionBeijing, China
| | - Zijian Feng
- Public Health Emergency Center, Chinese Center for Disease Control and PreventionBeijing, China
| | - Faxian Zhan
- Hubei Provincial Centre for Disease Control and PreventionWuhan, China
| | - Weizhong Yang
- Chinese Center for Disease Control and PreventionBeijing, China
| | - Timothy M Uyeki
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and PreventionAtlanta, GA, USA
| | - Yu Wang
- Chinese Center for Disease Control and PreventionBeijing, China
| | - Jay K Varma
- China-US Collaborative Program on Emerging and Re-emerging Infection Disease, US Centers for Disease Control and PreventionBeijing, China
- Global Disease Detection Program, Division of Global Disease Detection and Response, Center for Global Health, Centers for Disease Control and PreventionAtlanta, GA, USA
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Lan YC, Su MC, Chen CH, Huang SH, Chen WL, Tien N, Lin CW. Epidemiology of pandemic influenza A/H1N1 virus during 2009-2010 in Taiwan. Virus Res 2013; 177:46-54. [PMID: 23886669 DOI: 10.1016/j.virusres.2013.07.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 06/14/2013] [Accepted: 07/11/2013] [Indexed: 11/15/2022]
Abstract
Outbreak of swine-origin influenza A/H1N1 virus (pdmH1N1) occurred in 2009. Taiwanese authorities implemented nationwide vaccinations with pdmH1N1-specific inactivated vaccine as of November 2009. This study evaluates prevalence, HA phylogenetic relationship, and transmission dynamic of influenza A and B viruses in Taiwan in 2009-2010. Respiratory tract specimens were analyzed for influenza A and B viruses. The pdmH1N1 peaked in November 2009, was predominant from August 2009 to January 2010, then sharply dropped in February 2010. Significant prevalence peaks of influenza B in April-June of 2010 and H3N2 virus in July and August were observed. Highest percentage of pdmH1N1- and H3N2-positive cases appeared among 11-15-year-olds; influenza B-positive cases were dominant among those 6-10 years old. Maximum likelihood phylogenetic trees showed 11 unique clusters of pdmH1N1, seasonal H3N2 influenza A and B viruses, as well as transmission clusters and mixed infections of influenza strains in Taiwan. The 2009 pdmH1N1 virus was predominant in Taiwan from August 2009 to January 2010; seasonal H3N2 influenza A and B viruses exhibited small prevalence peaks after nationwide vaccinations. Phylogenetic evidence indicated transmission clusters and multiple independent clades of co-circulating influenza A and B strains in Taiwan.
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Affiliation(s)
- Yu-Ching Lan
- Department of Health Risk Management, School of Public, China Medical University, Taichung, Taiwan
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A review of the evidence to support influenza vaccine introduction in countries and areas of WHO's Western Pacific Region. PLoS One 2013; 8:e70003. [PMID: 23875015 PMCID: PMC3713047 DOI: 10.1371/journal.pone.0070003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 06/17/2013] [Indexed: 11/24/2022] Open
Abstract
Background Immunization against influenza is considered an essential public health intervention to control both seasonal epidemics and pandemic influenza. According to the World Health Organization (WHO), there are five key policy and three key programmatic issues that decision-makers should consider before introducing a vaccine. These are (a) public health priority, (b) disease burden, (c) efficacy, quality and safety of the vaccine, (d) other inventions, (e) economic and financial issues, (f) vaccine presentation, (g) supply availability and (h) programmatic strength. We analyzed the body of evidence currently available on these eight issues in the WHO Western Pacific Region. Methodology/Principal Findings Studies indexed in PubMed and published in English between 1 January 2000 and 31 December 2010 from the 37 countries and areas of the Western Pacific Region were screened for keywords pertaining to the five policy and three programmatic issues. Studies were grouped according to country income level and vaccine target group. There were 133 articles that met the selection criteria, with most (90%) coming from high-income countries. Disease burden (n = 34), vaccine efficacy, quality and safety (n = 27) and public health priority (n = 27) were most frequently addressed by studies conducted in the Region. Many studies assessed influenza vaccine policy and programmatic issues in the general population (42%), in the elderly (24%) and in children (17%). Few studies (2%) addressed the eight issues relating to pregnant women. Conclusions/Significance The evidence for vaccine introduction in countries and areas in this Region remains limited, particularly in low- and middle-income countries that do not currently have influenza vaccination programmes. Surveillance activities and specialized studies can be used to assess the eight issues including disease burden among vaccine target groups and the cost-effectiveness of influenza vaccine. Multi-country studies should be considered to maximize resource utilization for cross-cutting issues such as vaccine presentation and other inventions.
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Chadha MS, Hirve S, Dawood FS, Lele P, Deoshatwar A, Sambhudas S, Juvekar S, LaFond KE, Mott JA, Lal RB, Mishra AC. Burden of seasonal and pandemic influenza-associated hospitalization during and after 2009 A(H1N1)pdm09 pandemic in a rural community in India. PLoS One 2013; 8:e55918. [PMID: 23690913 PMCID: PMC3654970 DOI: 10.1371/journal.pone.0055918] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 01/03/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Influenza is vaccine-preventable; however, the burden of severe influenza in India remains unknown. We conducted a population-based study to estimate the incidence of laboratory confirmed influenza-associated hospitalizations in a rural community in western India. METHODS We conducted active surveillance for hospitalized patients with acute medical illnesses or acute chronic disease exacerbations in Pune during pandemic and post pandemic periods (May 2009-April 2011). Nasal and throat swabs were tested for influenza viruses. A community health utilization survey estimated the proportion of residents hospitalized with respiratory illness at non-study facilities and was used to adjust incidence estimates from facility-based surveillance. RESULTS Among 9,426 hospitalizations, 3,391 (36%) patients were enrolled; 665 of 3,179 (20.9%) tested positive for influenza. Of 665 influenza positives, 340 (51%) were pandemic A(H1N1)pdm09 and 327 (49%) were seasonal, including A/H3 (16%), A/H1 (3%) and influenza B (30%). The proportion of patients with influenza peaked during August 2009 (39%) and 2010 (42%). The adjusted annual incidence of influenza hospitalizations was 46.8/10,000 during pandemic and 40.5/10,000 during post-pandemic period with comparable incidence of A(H1N1)pdm09 during both periods (18.8 and 20.3, respectively). The incidence of both pH1N1 and seasonal hospitalized influenza disease was highest in the 5-29 year olds. CONCLUSIONS We document the previously unrecognized burden of influenza hospitalization in a rural community following the emergence of influenza A(H1N1)pdm09 viruses in India. During peak periods of influenza activity circulation i.e during the monsoon period, 20% of all hospital admissions in the community had influenza positivity. These findings can inform development of influenza prevention and control strategies in India.
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Affiliation(s)
- Mandeep S. Chadha
- National Institute of Virology, Indian Council of Medical Research, Pune, India
- * E-mail: (MSC); (ACM)
| | - Siddhivinayak Hirve
- Vadu Rural Health Program, King Edward Memorial Hospital Research Center, Pune, India
| | - Fatimah S. Dawood
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Pallavi Lele
- Vadu Rural Health Program, King Edward Memorial Hospital Research Center, Pune, India
| | - Avinash Deoshatwar
- National Institute of Virology, Indian Council of Medical Research, Pune, India
- Vadu Rural Health Program, King Edward Memorial Hospital Research Center, Pune, India
| | - Somnath Sambhudas
- Vadu Rural Health Program, King Edward Memorial Hospital Research Center, Pune, India
| | - Sanjay Juvekar
- Vadu Rural Health Program, King Edward Memorial Hospital Research Center, Pune, India
| | - Kathryn E. LaFond
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Joshua A. Mott
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Renu B. Lal
- Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Akhilesh C. Mishra
- National Institute of Virology, Indian Council of Medical Research, Pune, India
- * E-mail: (MSC); (ACM)
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Estimation of the national disease burden of influenza-associated severe acute respiratory illness in Kenya and Guatemala: a novel methodology. PLoS One 2013; 8:e56882. [PMID: 23573177 PMCID: PMC3584100 DOI: 10.1371/journal.pone.0056882] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 01/15/2013] [Indexed: 11/19/2022] Open
Abstract
Background Knowing the national disease burden of severe influenza in low-income countries can inform policy decisions around influenza treatment and prevention. We present a novel methodology using locally generated data for estimating this burden. Methods and Findings This method begins with calculating the hospitalized severe acute respiratory illness (SARI) incidence for children <5 years old and persons ≥5 years old from population-based surveillance in one province. This base rate of SARI is then adjusted for each province based on the prevalence of risk factors and healthcare-seeking behavior. The percentage of SARI with influenza virus detected is determined from provincial-level sentinel surveillance and applied to the adjusted provincial rates of hospitalized SARI. Healthcare-seeking data from healthcare utilization surveys is used to estimate non-hospitalized influenza-associated SARI. Rates of hospitalized and non-hospitalized influenza-associated SARI are applied to census data to calculate the national number of cases. The method was field-tested in Kenya, and validated in Guatemala, using data from August 2009–July 2011. In Kenya (2009 population 38.6 million persons), the annual number of hospitalized influenza-associated SARI cases ranged from 17,129–27,659 for children <5 years old (2.9–4.7 per 1,000 persons) and 6,882–7,836 for persons ≥5 years old (0.21–0.24 per 1,000 persons), depending on year and base rate used. In Guatemala (2011 population 14.7 million persons), the annual number of hospitalized cases of influenza-associated pneumonia ranged from 1,065–2,259 (0.5–1.0 per 1,000 persons) among children <5 years old and 779–2,252 cases (0.1–0.2 per 1,000 persons) for persons ≥5 years old, depending on year and base rate used. In both countries, the number of non-hospitalized influenza-associated cases was several-fold higher than the hospitalized cases. Conclusions Influenza virus was associated with a substantial amount of severe disease in Kenya and Guatemala. This method can be performed in most low and lower-middle income countries.
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17
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Liu Y, Wang J, Ji J, Chang S, Xue C, Ma J, Bi Y, Xie Q. Phylogenetic diversity and genotypic complexity of H1N1 subtype swine influenza viruses isolated in mainland China. Virol J 2012. [PMID: 23181491 PMCID: PMC3585526 DOI: 10.1186/1743-422x-9-289] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Background After the occurrence of 2009 pandemic H1N1, close attention has been paid to the H1N1 subtype swine influenza viruses (H1N1 SIV) by scientific communities in many countries. A large-scale sequence analysis of the NCBI Influenza Virus Resource Database on H1N1 SIVs submitted primarily by scientists in China during 1992 to 2011 was performed. The aims of this study were to elucidate the genetic and evolutionary characteristics of H1N1 SIVs, to identify and unify the lineages and genetic characteristics of the H1N1 SIVs isolated in mainland China. Results Most of the strains were isolated during the period of 2008 to 2010 from Guangdong and Shandong provinces, China. Based on the phylogenetic and genotypic analyses, all of the H1N1 SIV strains can be classified into 8 lineages and 10 genotypes. All strains were of the characteristics of low pathogenic influenza viruses. The viruses of different lineage are characterized with different amino acid residues at the receptor-binding sites. Viruses containing PB2 genes of the classical swine, early seasonal human and recent seasonal human lineage might be more infectious to human. Some genotypes were directly related with human influenza viruses, which include strains that harbored genes derived from human influenza viruses. Conclusions Phylogenetic diversity and complexity existed in H1N1 SIVs isolated in mainland China. These H1N1 SIV strains were closely related to other subtype influenza viruses, especially to human influenza viruses. Moreover, it was shown that, novel lineages and genotypes of H1N1 SIVs emerged recently in mainland China. These findings provided new and essential information for further understanding of the genetic and evolutionary characteristics and monitoring the H1N1 SIVs in mainland China.
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Affiliation(s)
- Yizhi Liu
- College of Animal Science, South China Agricultural University, Guangzhou, 510642, China
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18
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Feikin DR, Ope MO, Aura B, Fuller JA, Gikunju S, Vulule J, Ng'ang'a Z, Njenga MK, Breiman RF, Katz M. The population-based burden of influenza-associated hospitalization in rural western Kenya, 2007-2009. Bull World Health Organ 2012; 90:256-263A. [PMID: 22511821 DOI: 10.2471/blt.11.094326] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 12/08/2011] [Accepted: 12/09/2011] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To estimate the burden and age-specific rates of influenza-associated hospitalization in rural western Kenya. METHODS All 3924 patients with respiratory illness (defined as acute cough, difficulty in breathing or pleuritic chest pain) who were hospitalized between June 2007 and May 2009 in any inpatient health facility in the Kenyan district of Bondo were enrolled. Nasopharyngeal and oropharyngeal swabs were collected and tested for influenza viruses using real-time reverse transcriptase polymerase chain reaction (RT-PCR). In the calculation of annual rates, adjustments were made for enrolled patients who did not have swabs tested for influenza virus. FINDINGS Of the 2079 patients with tested swabs, infection with influenza virus was confirmed in 204 (10%); 176, 27 and 1 were found to be RT-PCR-positive for influenza A virus only, influenza B virus only, and both influenza A and B viruses, respectively. Among those tested for influenza virus, 6.8% of the children aged < 5 years and 14.0% of the patients aged ≥ 5 years were found positive. The case-fatality rate among admitted patients with PCR-confirmed infection with influenza virus was 2.0%. The annual rate of hospitalization (per 100,000 population) was 699.8 among patients with respiratory illness and 56.2 among patients with influenza (with 143.7, 18.8, 55.2, 65.1 and 57.3 hospitalized patients with influenza virus per 100,000 people aged < 5, 5-19, 20-34, 35-49 and ≥ 50 years, respectively). CONCLUSION In a rural district of western Kenya, the rate of influenza-associated hospitalization was highest among children aged less than 5 years.
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Affiliation(s)
- Daniel R Feikin
- Centers for Disease Control and Prevention, PO Box 1578, Kisumu, Kenya.
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19
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A population-based study on incidence and economic burden of influenza-like illness in south China, 2007. Public Health 2011; 125:389-95. [DOI: 10.1016/j.puhe.2011.03.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 12/21/2010] [Accepted: 03/05/2011] [Indexed: 11/21/2022]
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20
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Tomas J, Lelièvre F, Bercelli P, Glanddier PY, Fanello S, Tuffreau F, Tallec A. Hospital admissions related to influenza in France during the 2006/2007 epidemic. Rev Epidemiol Sante Publique 2011; 59:159-67. [PMID: 21621359 DOI: 10.1016/j.respe.2011.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 11/29/2010] [Accepted: 01/05/2011] [Indexed: 10/18/2022] Open
Abstract
BACKGROUND The data available on hospital admissions related to influenza mostly concern in-patients admitted via the emergency department. Severe cases have been collated by intensive care practitioners since 2009. For this survey, we searched French hospital admission databases to estimate the prevalence rate of hospital admissions related to influenza and to record qualitative data. METHOD All case studies identified between October 2006 and September 2007 were split into two groups: the first displaying symptoms of clinical influenza and the second suffering from influenza as an associated diagnosis. RESULTS We collected 6797 hospital admissions, 2126 of which were closely related to clinical influenza. Fifty percent of cases concerned the elderly and young people. Fifty-six hospital deaths were recorded in which influenza was the underlying cause in 21% of the cases (12). When influenza was an associated diagnosis (44/56), cardiovascular or respiratory diseases were the main causes (26/44). CONCLUSION During the same period (2006-2007), the French Sentinel Surveillance identified only 105 hospital admissions related to influenza. Our survey was therefore more exhaustive and was able to record qualitative data. Inclusion of hospital admissions with an associated diagnosis of influenza is debatable because this decreases specificity. The relationship between the principal diagnosis and all the associated diagnoses is difficult to study, although exclusion of this type of hospitalization could significantly underestimate these figures. Despite certain limitations, French hospital admissions databases should complement French Sentinel Surveillance data.
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Affiliation(s)
- J Tomas
- Observatoire Régional de la Santé (ORS) Pays de la Loire, Hôtel de la Région, 1 Rue de la Loire, 44966 Nantes Cedex 9, France.
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21
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Cohen C, Simonsen L, Kang JW, Miller M, McAnerney J, Blumberg L, Schoub B, Madhi SA, Viboud C. Elevated influenza-related excess mortality in South African elderly individuals, 1998-2005. Clin Infect Dis 2010; 51:1362-9. [PMID: 21070141 PMCID: PMC3106243 DOI: 10.1086/657314] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Accepted: 08/30/2010] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Although essential to guide control measures, published estimates of influenza-related seasonal mortality for low- and middle-income countries are few. We aimed to compare influenza-related mortality among individuals aged ≥65 years in South Africa and the United States. METHODS We estimated influenza-related excess mortality due to all causes, pneumonia and influenza, and other influenza-associated diagnoses from monthly age-specific mortality data for 1998-2005 using a Serfling regression model. We controlled for between-country differences in population age structure and nondemographic factors (baseline mortality and coding practices) by generating age-standardized estimates and by estimating the percentage excess mortality attributable to influenza. RESULTS Age-standardized excess mortality rates were higher in South Africa than in the United States: 545 versus 133 deaths per 100,000 population for all causes (P<.001) and 63 vs 21 deaths per 100,000 population for pneumonia and influenza (P=.03). Standardization for nondemographic factors decreased but did not eliminate between-country differences; for example, the mean percentage of winter deaths attributable to influenza was 16% in South Africa and 6% in the United States (P<.001). For all respiratory causes, cerebrovascular disease, and diabetes, age-standardized excess death rates were 4-8-fold greater in South Africa than in the United States, and the percentage increase in winter deaths attributable to influenza was 2-4-fold higher. CONCLUSIONS These data suggest that the impact of seasonal influenza on mortality among elderly individuals may be substantially higher in an African setting, compared with in the United States, and highlight the potential for influenza vaccination programs to decrease mortality.
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Affiliation(s)
- Cheryl Cohen
- National Institute for Communicable Diseases of the National Health Laboratory Service, South Africa.
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Juzeniene A, Ma LW, Kwitniewski M, Polev GA, Lagunova Z, Dahlback A, Moan J. The seasonality of pandemic and non-pandemic influenzas: the roles of solar radiation and vitamin D. Int J Infect Dis 2010; 14:e1099-105. [PMID: 21036090 DOI: 10.1016/j.ijid.2010.09.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 08/08/2010] [Accepted: 09/01/2010] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVES Seasonal variations in ultraviolet B (UVB) radiation cause seasonal variations in vitamin D status. This may influence immune responses and play a role in the seasonality of influenza. METHODS Pandemic and non-pandemic influenzas in Sweden, Norway, the USA, Singapore, and Japan were studied. Weekly/monthly influenza incidence and death rates were evaluated in view of monthly UVB fluences. RESULTS Non-pandemic influenzas mostly occur in the winter season in temperate regions. UVB calculations show that at high latitudes very little, if any, vitamin D is produced in the skin during the winter. Even at 26°N (Okinawa) there is about four times more UVB during the summer than during the winter. In tropical regions there are two minor peaks in vitamin D photosynthesis, and practically no seasonality of influenza. Pandemics may start with a wave in an arbitrary season, while secondary waves often occur the following winter. Thus, it appears that a low vitamin D status may play a significant role in most influenzas. CONCLUSIONS In temperate latitudes even pandemic influenzas often show a clear seasonality. The data support the hypothesis that high fluences of UVB radiation (vitamin D level), as occur in the summer, act in a protective manner with respect to influenza.
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Affiliation(s)
- Asta Juzeniene
- Department of Radiation Biology, Institute for Cancer Research, the Norwegian Radium Hospital, Oslo University Hospital, Montebello, N-0310 Oslo, Norway.
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Chau PH, Woo J, Chan KC, Weisz D, Gusmano MK. Avoidable mortality pattern in a Chinese population—Hong Kong, China. Eur J Public Health 2010; 21:215-20. [PMID: 20237173 DOI: 10.1093/eurpub/ckq020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Simmerman JM, Chittaganpitch M, Levy J, Chantra S, Maloney S, Uyeki T, Areerat P, Thamthitiwat S, Olsen SJ, Fry A, Ungchusak K, Baggett HC, Chunsuttiwat S. Incidence, seasonality and mortality associated with influenza pneumonia in Thailand: 2005-2008. PLoS One 2009; 4:e7776. [PMID: 19936224 PMCID: PMC2777392 DOI: 10.1371/journal.pone.0007776] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 10/06/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Data on the incidence, seasonality and mortality associated with influenza in subtropical low and middle income countries are limited. Prospective data from multiple years are needed to develop vaccine policy and treatment guidelines, and improve pandemic preparedness. METHODS During January 2005 through December 2008, we used an active, population-based surveillance system to prospectively identify hospitalized pneumonia cases with influenza confirmed by reverse transcriptase-polymerase chain reaction or cell culture in 20 hospitals in two provinces in Thailand. Age-specific incidence was calculated and extrapolated to estimate national annual influenza pneumonia hospital admissions and in-hospital deaths. RESULTS Influenza was identified in 1,346 (10.4%) of pneumonia patients of all ages, and 10 influenza pneumonia patients died while in the hospital. 702 (52%) influenza pneumonia patients were less than 15 years of age. The average annual incidence of influenza pneumonia was greatest in children less than 5 years of age (236 per 100,000) and in those age 75 or older (375 per 100,000). During 2005, 2006 and 2008 influenza A virus detection among pneumonia cases peaked during June through October. In 2007 a sharp increase was observed during the months of January through April. Influenza B virus infections did not demonstrate a consistent seasonal pattern. Influenza pneumonia incidence was high in 2005, a year when influenza A(H3N2) subtype virus strains predominated, low in 2006 when A(H1N1) viruses were more common, moderate in 2007 when H3N2 and influenza B co-predominated, and high again in 2008 when influenza B viruses were most common. During 2005-2008, influenza pneumonia resulted in an estimated annual average 36,413 hospital admissions and 322 in-hospital pneumonia deaths in Thailand. CONCLUSION Influenza virus infection is an important cause of hospitalized pneumonia in Thailand. Young children and the elderly are most affected and in-hospital deaths are more common than previously appreciated. Influenza occurs year-round and tends to follow a bimodal seasonal pattern with substantial variability. The disease burden varies significantly from year to year. Our findings support a recent Thailand Ministry of Public Health (MOPH) decision to extend annual influenza vaccination to older adults and suggest that children should also be targeted for routine vaccination.
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Affiliation(s)
- James Mark Simmerman
- International Emerging Infections Program, Thailand Ministry of Public Health-United States Centers for Disease Control Collaboration, Nonthaburi, Thailand.
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Warren-Gash C, Smeeth L, Hayward AC. Influenza as a trigger for acute myocardial infarction or death from cardiovascular disease: a systematic review. THE LANCET. INFECTIOUS DISEASES 2009; 9:601-10. [PMID: 19778762 DOI: 10.1016/s1473-3099(09)70233-6] [Citation(s) in RCA: 342] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cardiac complications of influenza infection, such as myocarditis, are well recognised, but the role of influenza as a trigger of acute myocardial infarction is less clear. We did a systematic review of the evidence that influenza (including influenza-like illness and acute respiratory infection) triggers acute myocardial infarction or cardiovascular death. We examined the effectiveness of influenza vaccines at protecting against cardiac events and did a meta-analysis of data from randomised controlled trials. 42 publications describing 39 studies were identified. Many observational studies in different settings with a range of methods reported consistent associations between influenza and acute myocardial infarction. There was weaker evidence of an association with cardiovascular death. Two small randomised trials assessed the protection provided by influenza vaccine against cardiac events in people with existing cardiovascular disease. Whereas one trial found that influenza vaccination gave significant protection against cardiovascular death, the other trial was inconclusive. A pooled estimate from a random-effects model suggests a protective, though non-significant, effect (relative risk 0.51, 95% CI 0.15-1.76). We believe influenza vaccination should be encouraged wherever indicated, especially in people with existing cardiovascular disease, among whom there is often suboptimum vaccine uptake. Further evidence is needed on the effectiveness of influenza vaccines to reduce the risk of cardiac events in people without established vascular disease.
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Ortiz JR, Sotomayor V, Uez OC, Oliva O, Bettels D, McCarron M, Bresee JS, Mounts AW. Strategy to enhance influenza surveillance worldwide. Emerg Infect Dis 2009; 15:1271-8. [PMID: 19751590 PMCID: PMC2815958 DOI: 10.3201/eid1508.081422] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The emergence of a novel strain of influenza virus A (H1N1) in April 2009 focused attention on influenza surveillance capabilities worldwide. In consultations before the 2009 outbreak of influenza subtype H1N1, the World Health Organization had concluded that the world was unprepared to respond to an influenza pandemic, due in part to inadequate global surveillance and response capacity. We describe a sentinel surveillance system that could enhance the quality of influenza epidemiologic and laboratory data and strengthen a country's capacity for seasonal, novel, and pandemic influenza detection and prevention. Such a system would 1) provide data for a better understanding of the epidemiology and extent of seasonal influenza, 2) provide a platform for the study of other acute febrile respiratory illnesses, 3) provide virus isolates for the development of vaccines, 4) inform local pandemic planning and vaccine policy, 5) monitor influenza epidemics and pandemics, and 6) provide infrastructure for an early warning system for outbreaks of new virus subtypes.
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Hanshaoworakul W, Simmerman JM, Narueponjirakul U, Sanasuttipun W, Shinde V, Kaewchana S, Areechokechai D, Levy J, Ungchusak K. Severe human influenza infections in Thailand: oseltamivir treatment and risk factors for fatal outcome. PLoS One 2009; 4:e6051. [PMID: 19557130 PMCID: PMC2699035 DOI: 10.1371/journal.pone.0006051] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Accepted: 05/24/2009] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Influenza is often not recognized as an important cause of severe or fatal disease in tropical and subtropical countries in Southeast Asia. The extent to which Oseltamivir treatment may protect against a fatal outcome in severe influenza infections is not known. Thailand's National Avian Influenza Surveillance (NAIS) system affords a unique opportunity to describe the epidemiology of laboratory-confirmed severe and fatal human influenza infections. METHODOLOGY/PRINCIPAL FINDINGS During January 2004 through December 2006, 11,641 notifications to the NAIS were investigated in 73 of 76 Thai provinces. Clinical and demographic data and respiratory swab specimens were collected and tested by PCR for influenza. Using the NAIS database, we identified all patients with laboratory confirmed human influenza (A/H3N2, A/H1N1 and Type B) infection. A retrospective medical record review was conducted on all fatal cases with laboratory confirmed influenza and from a sample of hospitalized cases in 28 provinces. The association of underlying risk factors, Oseltamivir treatment and risk of a fatal outcome were examined. Human influenza infections were identified in 2,075 (18%) cases. Twenty-two (1%) deaths occurred including seven deaths in children less than ten years of age. Thirty-five percent of hospitalized human influenza infections had chest X-ray confirmed pneumonia. Current or former smoking; advanced age, hypertension and underlying cardiovascular, pulmonary or endocrine disease were associated with a fatal outcome from human influenza infection. Treatment with Oseltamivir was statistically associated with survival with a crude OR of .11 (95% CI: 0.04-0.30) and .13 (95% CI: 0.04-0.40) after controlling for age. CONCLUSIONS Severe and fatal human influenza infections were commonly identified in the NAIS designed to identify avian A/H5N1 cases. Treatment with Oseltamivir is associated with survival in hospitalized human influenza pneumonia patients.
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Affiliation(s)
- Wanna Hanshaoworakul
- Bureau of Epidemiology, Thailand Ministry of Public Health, Nonthaburi, Thailand
| | - James Mark Simmerman
- International Emerging Infections Program, Thailand MOPH – U. S. CDC Collaboration, Ministry of Public Health, Nonthaburi, Thailand
| | | | - Wiwan Sanasuttipun
- International Emerging Infections Program, Thailand MOPH – U. S. CDC Collaboration, Ministry of Public Health, Nonthaburi, Thailand
| | - Vivek Shinde
- Influenza Division, U. S. Centers for Disease Control, Atlanta, Georgia, United States of America
| | - Suchada Kaewchana
- International Emerging Infections Program, Thailand MOPH – U. S. CDC Collaboration, Ministry of Public Health, Nonthaburi, Thailand
| | - Darin Areechokechai
- Bureau of Epidemiology, Thailand Ministry of Public Health, Nonthaburi, Thailand
| | - Jens Levy
- International Emerging Infections Program, Thailand MOPH – U. S. CDC Collaboration, Ministry of Public Health, Nonthaburi, Thailand
| | - Kumnuan Ungchusak
- Bureau of Epidemiology, Thailand Ministry of Public Health, Nonthaburi, Thailand
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Simmerman JM, Uyeki TM. The burden of influenza in East and South-East Asia: a review of the English language literature. Influenza Other Respir Viruses 2009; 2:81-92. [PMID: 19453467 PMCID: PMC4634698 DOI: 10.1111/j.1750-2659.2008.00045.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Abstract While human infections with avian influenza A (H5NI) viruses in Asia have prompted concerns about an influenza pandemic, the burden of human influenza in East and Southeast Asia has received far less attention. We conducted a review of English language articles on influenza in 18 countries in East and Southeast Asia published from 1980 to 2006 that were indexed on PubMed. Articles that described human influenza‐associated illnesses among outpatients or hospitalized patients, influenza‐associated deaths, or influenza‐associated socioeconomic costs were reviewed. We found 35 articles from 9 countries that met criteria for inclusion in the review. The quality of articles varied substantially. Significant heterogeneity was noted in case definitions, sampling schemes and laboratory methods. Early studies relied on cell culture, had difficulties with specimen collection and handling, and reported a low burden of disease. The recent addition of PCR testing has greatly improved the proportion of respiratory illnesses diagnosed with influenza. These more recent studies reported that 11–26% of outpatient febrile illness and 6‐14% of hospitalized pneumonia cases had laboratory‐confirmed influenza infection. The influenza disease burden literature from East and Southeast Asia is limited but expanding. Recent studies using improved laboratory testing methods and indirect statistical approaches report a substantial burden of disease, similar to that of Europe and North America. Current increased international focus on influenza, coupled with unprecedented funding for surveillance and research, provide a unique opportunity to more comprehensively describe the burden of human influenza in the region.
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Affiliation(s)
- James M Simmerman
- Thailand MOPH-U.S. CDC Collaboration, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand.
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Newall AT, Kelly H, Harsley S, Scuffham PA. Cost effectiveness of influenza vaccination in older adults: a critical review of economic evaluations for the 50- to 64-year age group. PHARMACOECONOMICS 2009; 27:439-450. [PMID: 19640008 DOI: 10.2165/00019053-200927060-00001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Several recent studies have assessed the benefits of extending influenza vaccination programmes, which are currently targeted primarily at those aged over 65 years, to those aged 50-64 years. We identified and reviewed all cost-effectiveness studies of influenza vaccination in those aged 50-64 years published before July 2008. While the studies suggest that vaccination in this age-group is likely to be cost effective, these results were dependent on several key assumptions. The estimates of serious outcomes due to influenza and the estimates of vaccine effectiveness (VE) against these outcomes were found to have the most influence on cost effectiveness. However, due to factors including mismatches between the measure of VE and the outcome under consideration, as well as various other data limitations, there is significant uncertainty around these key assumptions that was not well explored. There was a failure in some studies to report fundamental inputs such as discount rates. Overall, there was a general lack of transparency in the studies and, consequently, the conclusions around the cost effectiveness of influenza vaccine in those aged 50-64 years must be interpreted with caution.
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Affiliation(s)
- Anthony T Newall
- School of Public Health and Community Medicine, University of New South Wales, Sydney, New South Wales, Australia
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CHAN-YEUNG M, LAI CK, CHAN KS, CHEUNG AH, YAO TJ, HO AS, KO FW, YAM LY, WONG PC, TSANG KW, LAM WK, HO JC, CHU CM, YU WC, CHAN HS, IP MS, HUI DS, TAM CY. The burden of lung disease in Hong Kong: A report from the Hong Kong Thoracic Society. Respirology 2008; 13 Suppl 4:S133-65. [DOI: 10.1111/j.1440-1843.2008.01394.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Newall AT, Wood JG, MacIntyre CR. Influenza-related hospitalisation and death in Australians aged 50 years and older. Vaccine 2008; 26:2135-41. [PMID: 18325639 PMCID: PMC7125633 DOI: 10.1016/j.vaccine.2008.01.051] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 01/22/2008] [Accepted: 01/30/2008] [Indexed: 11/21/2022]
Abstract
Estimating the true burden of influenza is problematic because relatively few hospitalisations or deaths are specifically coded as influenza related. Statistical regression techniques using influenza and respiratory syncytial virus surveillance data were used to estimate the number of excess hospitalisations and deaths attributable to influenza. Several International Classification of Diseases 10th Revision (ICD-10) groupings were used for both hospitalisation and mortality estimates, including influenza and pneumonia, other respiratory disorders, and circulatory disorders. For Australians aged 50-64 years, the annual excess hospitalisations attributable to influenza were 33.3 (95%CI: 23.2-43.4) per 100,000 for influenza and pneumonia and 57.6 (95%CI: 32.5-82.8) per 100,000 for other respiratory disorders. For Australians aged > or =65 years, the annual excess hospitalisations attributable to influenza were 157.4 (95%CI: 108.4-206.5) per 100,000 for influenza and pneumonia and 282.0 (95%CI: 183.7-380.3) per 100,000 for other respiratory disorders. The annual excess all-cause mortality attributable to influenza was 6.4 (95%CI: 2.6-10.2) per 100,000 and 116.4 (95%CI: 71.3-161.5) per 100,000, for Australians aged 50-64 years and those aged > or =65 years, respectively. In the age-group > or =65 years, a significant association was found between influenza activity and circulatory mortality. We conclude that influenza is responsible for a substantial amount of mortality and morbidity, over and above that which is directly diagnosed as influenza in Australians aged > or =50 years.
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Affiliation(s)
- Anthony T. Newall
- The School of Public Health, The University of Sydney, NSW, Australia
- The School of Public Health and Community Medicine, University of New South Wales, NSW, Australia
- National Centre for Immunisation Research and Surveillance (NCIRS) of Vaccine Preventable Diseases, The Children's Hospital at Westmead, and The University of Sydney, Locked Bag 4001, NSW 2145, Australia
| | - James G. Wood
- The School of Public Health and Community Medicine, University of New South Wales, NSW, Australia
- National Centre for Immunisation Research and Surveillance (NCIRS) of Vaccine Preventable Diseases, The Children's Hospital at Westmead, and The University of Sydney, Locked Bag 4001, NSW 2145, Australia
| | - C. Raina MacIntyre
- The School of Public Health and Community Medicine, University of New South Wales, NSW, Australia
- National Centre for Immunisation Research and Surveillance (NCIRS) of Vaccine Preventable Diseases, The Children's Hospital at Westmead, and The University of Sydney, Locked Bag 4001, NSW 2145, Australia
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Newall AT, Scuffham PA, Kelly H, Harsley S, MacIntyre CR. The cost-effectiveness of a universal influenza vaccination program for adults aged 50–64 years in Australia. Vaccine 2008; 26:2142-53. [DOI: 10.1016/j.vaccine.2008.01.050] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 01/22/2008] [Accepted: 01/30/2008] [Indexed: 11/28/2022]
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Choi BCK, Morrison H, Wong T, Wu J, Yan YP. Bringing chronic disease epidemiology and infectious disease epidemiology back together. J Epidemiol Community Health 2007; 61:832. [PMID: 17699535 PMCID: PMC2660008 DOI: 10.1136/jech.2006.057752] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Bernard C K Choi
- Centre for Chronic Disease Prevention and Control, Public Health Agency of Canada, AL no 6701A, 120 Colonnade Road, Ottawa, Ontario, Canada.
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Genetic analysis of influenza A/H3N2 and A/H1N1 viruses circulating in Vietnam from 2001 to 2006. J Clin Microbiol 2007; 46:399-405. [PMID: 17942644 DOI: 10.1128/jcm.01549-07] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Influenza A virus has the ability to overcome immunity from previous infections through the acquisition of genetic changes. Thus, understanding the evolution of the viruses in humans is important for the surveillance and the selection of vaccine strains. A total of 30 influenza A/H3N2 viruses and 35 influenza A/H1N1 viruses that were collected in Vietnam from 2001 to 2006 were used to analyze the evolution of the hemagglutinin (HA), neuraminidase (NA), and matrix protein (M) genes. Phylogenetic analysis of individual gene segments revealed that the HA and the NA genes of the influenza A viruses evolved in a sequential way. However, the evolutionary pattern of the M gene proved to be nonlinear and was not linked with that of the HA and NA genes. Genetic drift in HA1 segments, especially in the antigenic sites of A/H3N2 viruses, occurred more frequently in A/H3N2 viruses than it did in A/H1N1 viruses. Two reassortants, one influenza A/H3N2 strain and one A/H1N1 strain, were found on the basis of the phylogenetic analysis of the three genes. While both genetic mutation and reassortment contributed to their evolution, the frequency of genetic changes and reassortment events differs between the two subtypes. As influenza viruses circulate throughout the year, we emphasize the importance of surveillance in tropical and subtropical zones, where the emergence of new strains may be detected earlier than it is in temperate zones.
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Nguyen HLK, Saito R, Ngiem HK, Nishikawa M, Shobugawa Y, Nguyen DC, Hoang LT, Huynh LP, Suzuki H. Epidemiology of influenza in Hanoi, Vietnam, from 2001 to 2003. J Infect 2007; 55:58-63. [PMID: 17222912 DOI: 10.1016/j.jinf.2006.12.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Revised: 11/30/2006] [Accepted: 12/01/2006] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The aim of this study was to clarify the epidemiology of laboratory-confirmed influenza in Hanoi, Vietnam. METHODS Influenza was detected by virus isolation from nasopharyngeal swabs of influenza-like-illness (ILI) patients who reported to outpatient clinics in Hanoi, Vietnam between 2001 and 2003, before the start of avian influenza A/H5N1 outbreaks. Influenza isolates were characterized by hemagglutinin inhibition test. RESULTS A total of 4708 nasopharyngeal swabs were collected from patients with ILI. Influenza was positive in 119 (2.5%) samples by virus isolation. Influenza circulated throughout the year, with possible two peaks in summer and winter. Influenza B viruses and A/H3N2 predominated in 2001 and 2002, respectively, and mixed circulation of A/H1N1, A/H3N2 and B were observed in 2003. The seasonality of influenza roughly matched with clinical case reports in the North Region by National Communicable Disease Surveillance in Vietnam. CONCLUSIONS The findings of year-round and biannual peak circulation of influenza in a subtropical area were in accordance with the results of previous studies in tropical and subtropical regions. Our observations indicated that establishment of laboratory-based surveillance in tropical and sub-tropical countries is important for taking actions for pandemic strategies, and links to the WHO global influenza network.
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Affiliation(s)
- Hang L K Nguyen
- National Institute of Hygiene and Epidemiology, 1 Yersin Street, Hanoi, Vietnam
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