Dengue outlook for the World Cup in Brazil: an early warning model framework driven by real-time seasonal climate forecasts.
BACKGROUND
With more than a million spectators expected to travel among 12 different cities in Brazil during the football World Cup, June 12-July 13, 2014, the risk of the mosquito-transmitted disease dengue fever is a concern. We addressed the potential for a dengue epidemic during the tournament, using a probabilistic forecast of dengue risk for the 553 microregions of Brazil, with risk level warnings for the 12 cities where matches will be played.


METHODS
We obtained real-time seasonal climate forecasts from several international sources (European Centre for Medium-Range Weather Forecasts [ECMWF], Met Office, Meteo-France and Centro de Previsão de Tempo e Estudos Climáticos [CPTEC]) and the observed dengue epidemiological situation in Brazil at the forecast issue date as provided by the Ministry of Health. Using this information we devised a spatiotemporal hierarchical Bayesian modelling framework that enabled dengue warnings to be made 3 months ahead. By assessing the past performance of the forecasting system using observed dengue incidence rates for June, 2000-2013, we identified optimum trigger alert thresholds for scenarios of medium-risk and high-risk of dengue.


RESULTS
Our forecasts for June, 2014, showed that dengue risk was likely to be low in the host cities Brasília, Cuiabá, Curitiba, Porto Alegre, and São Paulo. The risk was medium in Rio de Janeiro, Belo Horizonte, Salvador, and Manaus. High-risk alerts were triggered for the northeastern cities of Recife (p(high)=19%), Fortaleza (p(high)=46%), and Natal (p(high)=48%). For these high-risk areas, particularly Natal, the forecasting system did well for previous years (in June, 2000-13).


CONCLUSIONS
This timely dengue early warning permits the Ministry of Health and local authorities to implement appropriate, city-specific mitigation and control actions ahead of the World Cup.


BACKGROUND
European Commission's Seventh Framework Research Programme projects DENFREE, EUPORIAS, and SPECS; Conselho Nacional de Desenvolvimento Científico e Tecnológico and Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro.
Climate Dynamics and Impacts Unit, Institut Català de Ciències del Clima (IC3), Barcelona, Spain. Electronic address: rachel.lowe@ic3.cat.
Rachel
R
Lowe
Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ, Brazil.
Christovam
C
Barcellos
Centro de Previsão de Tempo e Estudos Climáticos, Instituto Nacional de Pesquisas Espaciais, Cachoeira Paulista, SP, Brazil.
Caio A S
CA
Coelho
Exeter Climate Systems, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK.
Trevor C
TC
Bailey
Coordenação Geral do Programa Nacional de Controle da Dengue, Ministério da Saúde, Brasília, DF, Brazil.
Giovanini Evelim
GE
Coelho
Met Office Hadley Centre, Exeter, Devon, UK.
Richard
R
Graham
Exeter Climate Systems, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK.
Tim
T
Jupp
Faculdade de Ceilândia, Universidade de Brasília, Brasília, DF, Brazil.
Walter Massa
WM
Ramalho
Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ, Brazil.
Marilia Sá
MS
Carvalho
Exeter Climate Systems, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK.
David B
DB
Stephenson
Climate Dynamics and Impacts Unit, Institut Català de Ciències del Clima (IC3), Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain.
Xavier
X
Rodó
D001499:Bayes Theorem; D001938:Brazil / Q000453:epidemiology; D002980:Climate; D003715:Dengue / Q000453:epidemiology*; D005544:Forecasting / Q000379:methods; D006801:Humans; D012306:Risk; D012621:Seasons; D012916:Soccer