Outbreak reports on dengue fever

Dengue outbreak in Madeira (2012-13)

From 26 September 2012 to 3 March 2013, the autonomous province of Madeira, Portugal, reported its first dengue outbreak (Dengue-1 virus). It was the first sustained transmission of dengue in the European Union since the 1920s. 

From 26 September 2012 to 3 March 2013, the autonomous province of Madeira, Portugal, reported its first dengue outbreak (Dengue-1 virus). Of the 2168 probable cases, 1080 were confirmed. No severe clinical forms were reported, and there were no fatalities.

As of 3 February 2013, 78 patients have been diagnosed in other European countries with dengue infection after returning from Madeira (continental Portugal 11, United Kingdom 23, Germany 19, Finland 7, Sweden 5, France 3, Denmark 2, Austria 2, Norway 2, Croatia 1, Slovenia 1, Spain 1, and Switzerland 1). The latest case was reported on 1 February 2013 from Finland.

Between week 4 and 19 (2013), imported cases from Angola (2) and Brazil (1) were identified.

The outbreak was mainly located in Funchal and neighbouring areas, notably Câmara de Lobos, São Martinho, and Caniço. Few cases were reported in other municipalities; these cases were most likely acquired in foci of active transmission.

Phylogenetic studies showed that the virus was most likely introduced from South America (Venezuela, Colombia, or northern Brazil).

The presence of Aedes (Ae.) aegypti mosquito, the main dengue vector, was detected for the first time in Funchal in 2005 and its presence was then recorded along the southern coast of the island, at low altitudes and in urban settings that provided an ecological niche for the establishment of the mosquito in Madeira.

Missions to Madeira

ECDC conducted a first mission in October 2012 to set up a specific epidemiological surveillance system based on information from the public healthcare system, the Madeira Dengue Surveillance System. Using this tool, the local authorities were able to follow the spatio-temporal evolution of the outbreak. Results were published in an epidemiological bulletin for the main stakeholders.

In March 2013, ECDC conducted a second mission to Madeira to retrospectively assess outbreak epidemiology as well as the public health measures and activities implemented between September 2012 and February 2013 and to
discuss with the local health authorities response and preparedness planning with regard to future scenarios. Upon request from the Portuguese Directorate-General of Health, the team conducted a SWOT analysis (strengths,
weaknesses, opportunities, and threats) of main activities related to dengue prevention and control in Madeira. The main outcomes of this analysis are presented in this report.