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ABSTRACT: Introduction
Determining the optimal time to vaccinate is important for influenza vaccination programmes. Here, we assessed the temporal characteristics of influenza epidemics in the Northern and Southern hemispheres and in the tropics, and discuss their implications for vaccination programmes.Methods
This was a retrospective analysis of surveillance data between 2000 and 2014 from the Global Influenza B Study database. The seasonal peak of influenza was defined as the week with the most reported cases (overall, A, and B) in the season. The duration of seasonal activity was assessed using the maximum proportion of influenza cases during three consecutive months and the minimum number of months with ?80% of cases in the season. We also assessed whether co-circulation of A and B virus types affected the duration of influenza epidemics.Results
212 influenza seasons and 571,907 cases were included from 30 countries. In tropical countries, the seasonal influenza activity lasted longer and the peaks of influenza A and B coincided less frequently than in temperate countries. Temporal characteristics of influenza epidemics were heterogeneous in the tropics, with distinct seasonal epidemics observed only in some countries. Seasons with co-circulation of influenza A and B were longer than influenza A seasons, especially in the tropics.Discussion
Our findings show that influenza seasonality is less well defined in the tropics than in temperate regions. This has important implications for vaccination programmes in these countries. High-quality influenza surveillance systems are needed in the tropics to enable decisions about when to vaccinate.
SUBMITTER: Caini S
PROVIDER: S-EPMC4816507 | biostudies-literature | 2016
REPOSITORIES: biostudies-literature
Caini Saverio S Andrade Winston W Badur Selim S Balmaseda Angel A Barakat Amal A Bella Antonino A Bimohuen Abderrahman A Brammer Lynnette L Bresee Joseph J Bruno Alfredo A Castillo Leticia L Ciblak Meral A MA Clara Alexey W AW Cohen Cheryl C Cutter Jeffery J Daouda Coulibaly C de Lozano Celina C De Mora Domenica D Dorji Kunzang K Emukule Gideon O GO Fasce Rodrigo A RA Feng Luzhao L Ferreira de Almeida Walquiria Aparecida WA Guiomar Raquel R Heraud Jean-Michel JM Holubka Olha O Huang Q Sue QS Kadjo Herve A HA Kiyanbekova Lyazzat L Kosasih Herman H Kusznierz Gabriela G Lara Jenny J Li Ming M Lopez Liza L Mai Hoang Phuong Vu PV Pessanha Henriques Cláudio Maierovitch CM Matute Maria Luisa ML Mironenko Alla A Moreno Brechla B Mott Joshua A JA Njouom Richard R Nurhayati Ospanova Akerke A Owen Rhonda R Pebody Richard R Pennington Kate K Puzelli Simona S Quynh Le Mai Thi MT Razanajatovo Norosoa Harline NH Rodrigues Ana A Rudi Juan Manuel JM Tzer Pin Lin Raymond R Venter Marietjie M Vernet Marie-Astrid MA Wangchuk Sonam S Yang Juan J Yu Hongjie H Zambon Maria M Schellevis François F Paget John J
PloS one 20160331 3
<h4>Introduction</h4>Determining the optimal time to vaccinate is important for influenza vaccination programmes. Here, we assessed the temporal characteristics of influenza epidemics in the Northern and Southern hemispheres and in the tropics, and discuss their implications for vaccination programmes.<h4>Methods</h4>This was a retrospective analysis of surveillance data between 2000 and 2014 from the Global Influenza B Study database. The seasonal peak of influenza was defined as the week with ...[more]