The Epidemiology of Interpandemic and Pandemic Influenza in Vietnam, 2007–2010
Open Access
- 12 March 2012
- journal article
- research article
- Published by Oxford University Press (OUP) in American Journal of Epidemiology
- Vol. 175 (10), 1062-1074
- https://doi.org/10.1093/aje/kws121
Abstract
Prospective community-based studies have provided fundamental insights into the epidemiology of influenza in temperate regions, but few comparable studies have been undertaken in the tropics. The authors conducted prospective influenza surveillance and intermittent seroprevalence surveys in a household-based cohort in Vietnam between December 2007 and April 2010, resulting in 1,793 person-seasons of influenza surveillance. Age- and sex-standardized estimates of the risk of acquiring any influenza infection per season in persons 5 years of age or older were 21.1% (95% confidence interval: 17.4, 24.7) in season 1, 26.4% (95% confidence interval: 22.6, 30.2) in season 2, and 17.0% (95% confidence interval: 13.6, 20.4) in season 3. Some individuals experienced multiple episodes of infection with different influenza types/subtypes in the same season (n = 27) or reinfection with the same subtype in different seasons (n = 22). The highest risk of influenza infection was in persons 5–9 years old, in whom the risk of influenza infection per season was 41.8%. Although the highest infection risk was in school-aged children, there were important heterogeneities in the age of infection by subtype and season. These heterogeneities could influence the impact of school closure and childhood vaccination on influenza transmission in tropical areas, such as Vietnam.Keywords
This publication has 52 references indexed in Scilit:
- Comparability of Different Methods for Estimating Influenza Infection Rates Over a Single Epidemic WaveAmerican Journal of Epidemiology, 2011
- Explaining rapid reinfections in multiple-wave influenza outbreaks: Tristan da Cunha 1971 epidemic as a case studyProceedings Of The Royal Society B-Biological Sciences, 2011
- Immuno-epidemiologic Correlates of Pandemic H1N1 Surveillance Observations: Higher Antibody and Lower Cell-Mediated Immune Responses with Advanced AgeThe Journal of Infectious Diseases, 2010
- The Infection Attack Rate and Severity of 2009 Pandemic H1N1 Influenza in Hong KongClinical Infectious Diseases, 2010
- Pandemic influenza preparedness and health systems challenges in Asia: results from rapid analyses in 6 Asian countriesBMC Public Health, 2010
- Pre-existing immunity against swine-origin H1N1 influenza viruses in the general human populationProceedings of the National Academy of Sciences, 2009
- The Global Circulation of Seasonal Influenza A (H3N2) VirusesScience, 2008
- The genomic and epidemiological dynamics of human influenza A virusNature, 2008
- Influenza-Associated Hospitalization in a Subtropical CityPLoS Medicine, 2006
- A Bayesian MCMC approach to study transmission of influenza: application to household longitudinal dataStatistics in Medicine, 2004