Article
Seasonal dynamics of influenza in Brazil: the latitude effect
Registration in:
ALMEIDA, Alexandra; CODEÇO, Cláudia; LUZ, Paula Mendes. Seasonal dynamics of influenza in Brazil: the latitude effect. BMC Infectious Diseases, p. 1-9, 2018.
1471-2334
10.1186/s12879-018-3484-z
Author
Almeida, Alexandra
Codeço, Cláudia
Luz, Paula Mendes
Abstract
Errata - Correction to: Seasonal dynamics of
influenza in Brazil: the latitude effect Background: Influenza is a global transmissible disease. Its dynamics is far better understood in temperate climates than in the tropics. We aim to close this knowledge gap between tropical and temperate regions by showing how the influenza seasonality evolves in Brazil, a tropical country that encompasses a wide range of latitudes and six climatic sub-types.
Methods: We analyzed a state-level, weekly Syndrome of Acute Respiratory Disease (SARI) incidence data ranging from 2010 to 2016. We combined two techniques hierarchically: first the wavelet decomposition technique to detect annual periodicity and then circular statistics to describe seasonal measures of the periodic states.
Results: We found significant annual periodicity in 44% of the states. For these, we calculated several seasonal
measures such as the center of gravity or mean timing of activity. The relationship between the seasonal signatures and latitude was clear and statistically significant. States with seasonal signature are clustered along the coast. Most Amazonian and Central West states exhibit no seasonal behavior. Among the seasonal states, influenza starts in Northeast region, spreading southbound.
Conclusions: Our study advances the comprehension of influenza seasonality in tropical areas and could be used to design more effective prevention and control strategies.