BRAZILIAN medical researchers have assessed the potential for a dengue epidemic during the World Cup football tournament (June 12-July 13). With more than a million spectators expected to travel among the 12 cities in Brazil where the matches will be played, the risk of the mosquito-transmitted disease dengue fever is a concern. Using a probabilistic forecast of dengue risk for the 553 micro regions of Brazil, the scientists were able to give risk level warnings for the 12 cities. The work has been reported in the latest issue of Lancet Infectious Diseases.
The researchers obtained real-time seasonal climate forecasts from several international sources (European Centre for Medium-Range Weather Forecasts; the Met Office, United Kingdom; and Meteo-France) and Brazil’s Centro de Previsao de Tempo e Estudos Climaticos and the observed dengue epidemiological situation in Brazil at the forecast issue date as provided by the Brazilian Ministry of Health. Using this information, they devised a statistical modelling framework that enabled dengue warnings to be made three months ahead. By assessing the past performance of the forecasting system using observed dengue incidence rates for June 2000-13, they identified optimum trigger alert thresholds for medium-risk and high-risk dengue scenarios.
Their findings for June 2014 showed that dengue risk was likely to be low in the host cities of Brasília, Cuiaba, Curitiba, Porto Alegre and Sao Paulo and medium in Rio de Janeiro, Belo Horizonte, Salvador and Manaus. High-risk alerts were triggered for the north-eastern cities of Recife (19 per cent), Fortaleza (46 per cent) and Natal (48 per cent). According to the researchers, for these high-risk areas, particularly Natal, the forecasting system did well for previous years.
R. Ramachandran
