Influenza‐associated mortality in Thailand, 2006–2011

• Published in: Influenza and other respiratory viruses Vol. 9; no. 6; pp. 298 - 304
• Main Authors: Aungkulanon, Suchunya, Cheng, Po‐Yung, Kusreesakul, Khanitta, Bundhamcharoen, Kanitta, Chittaganpitch, Malinee, Margaret, McCarron, Olsen, Sonja
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.11.2015; John Wiley & Sons, Ltd
• Subjects: Analysis; Developing countries; Influenza; Influenza vaccines; Influenza viruses; Mortality; Original; Thailand; tropical; tropical; mortality; Thailand; Influenza
• ISSN: 1750-2640; 1750-2659
• DOI: 10.1111/irv.12344

Background Influenza‐associated mortality in subtropical or tropical regions, particularly in developing countries, remains poorly quantified and often underestimated. We analyzed data in Thailand, a middle‐income tropical country with good vital statistics and influenza surveillance data. Methods We obtained weekly mortality data for all‐cause and three underlying causes of death (circulatory and respiratory diseases, and pneumonia and influenza), and weekly influenza virus data, from 2006 to 2011. A negative binomial regression model was used to estimate deaths attributable to influenza in two age groups (<65 and ≥65 years) by incorporating influenza viral data as covariates in the model. Results From 2006 to 2011, the average annual influenza‐associated mortality per 100 000 persons was 4·0 (95% CI: −18 to 26). Eighty‐three percent of influenza‐associated deaths occurred among persons aged > 65 years. The average annual rate of influenza‐associated deaths was 0·7 (95% CI: −8·2 to 10) per 100 000 population for person aged <65 years and 42 (95% CI: −137 to 216) for person aged ≥ 65 years. Discussion In Thailand, estimated excess mortality associated with influenza was considerable even during non‐pandemic years. These data provide support for Thailand's seasonal influenza vaccination campaign. Continued monitoring of mortality data is important to assess impact.