[Source: European Centre for Disease Prevention and Control (ECDC), full PDF document: (LINK). Extract.]
COMMUNICABLE DISEASE THREATS REPORT
Week 7, 10-16 February 2013 / CDTR
Dengue - Portugal - Madeira outbreak
Opening date: 10 October 2012 Latest update: 8 February 2013
On 3 October 2012, the Portuguese public health authorities reported two cases of dengue infection confirmed in patients residing on the island of Madeira in the Autonomous Region of Madeira located around 400 km from the Canary Islands, 650 km from the African coast, and 1 000 km from the European continent. The autonomous region has 268 000 inhabitants.
As of 3 February 2013, 2 164 cases of dengue infection have been reported from the public health sector in Madeira. The sequence analysis of viral genomes (600 nucleotides) from several positive human samples indicates high sequence similarity with DENV-1 circulating in Venezuela and Colombia, strongly suggesting a Latin American origin.
The vast majority of confirmed cases are from the city of Funchal, which is the main port on Madeira island. The island of Madeira has an established mosquito population of Aedes aegypti, the main vector of dengue in tropical and subtropical countries.
Seventy-eight patients have been diagnosed in European countries with dengue infection after returning from Madeira:
- 11 in Portugal,
- 23 in the UK,
- 19 in Germany,
- three in France,
- five in Sweden,
- seven in Finland,
- two in Denmark,
- two in Austria, and
- two in Norway.
- Croatia, Slovenia, Spain and Switzerland have all reported one case each.
The latest case was reported on 1 February 2013 from Finland.
This is the first known occurrence of locally transmitted dengue infection in the Autonomous Region of Madeira, and consequently a new geographical area reporting autochthonous cases in the EU. This is a significant public health event but not entirely unexpected because of the known presence of Aedes aegypti, a competent vector for dengue.
The latest figures from the Portuguese Ministry of Health indicate an important decrease of the number of notified cases reported since mid-November 2012, week 46 (see the 'Situação em 03/02/2013' update on the Dengue fever page of the Direção-Geral da Saúde website). However, disease transmission is still on-going with 28 cases reported in 2013 and three cases last week recorded by the local epidemiological surveillance system. This is indicative of an uninterrupted transmission occurring since the start of the outbreak and continuous vector activity.
The cases of dengue among returning travellers from the island highlight the need for travellers to Madeira to take measures in order to reduce mosquito bites. Travellers experiencing febrile symptoms with severe headache, retro-orbital pain, myalgia, arthralgia and maculo-papular rash within 21 days of visiting the island of Madeira are advised to seek medical advice.
Neighbouring geographical areas (e.g. Canary Islands) and other EU Member States need to assess the risk of establishment of Aedes mosquito populations and the introduction of dengue. The epidemiological situation does not imply the need for any trade or travel restriction beyond the disinfestation policies currently implemented.
ECDC published an updated rapid risk assessment concerning the autochthonous dengue cases in Madeira.
Portuguese authorities published recommendations regarding personal protective measures, and measures for the safety of blood, cells, tissues and organ donations within the region.
Blood donor deferral for 28 days from day of departure for travellers returning from the Autonomous region of Madeira is now recommended in other EU countries.
Dengue - Multistate (world) - Monitoring seasonal epidemics
Opening date: 20 April 2006 Latest update: 14 February 2013
Europe: There have been no reports of confirmed autochthonous dengue infections in Europe in 2013, besides the on-going dengue outbreak in Madeira.
Asia: Regional dengue activity is variable. While Cambodia, Lao PDR, Malaysia, Philippines, Singapore and Viet Nam all reported more cases as compared to the previous year for the same time period, the recent trend is declining or remains low in Cambodia, Lao PDR, Malaysia, and the Philippines. However, Australia and Singapore are experiencing an increase in dengue activity.
Latin America: In Central America, high dengue activity is reported across Mexico whilst Nicaragua has reported a decreasing trend in cases this week. In South America, there is an increasing trend in dengue activity reported in Brazil, Colombia, Ecuador, Venezuela and Paraguay.
The Pacific: There is still a fairly substantial dengue outbreak in New Caledonia which according to local health authorities may not have peaked yet. In January 2013, 965 new cases were identified and 470 cases have been recorded so far this month. Since the outbreak started in September 2012, a total of more than 1 900 cases of dengue fever have been recorded. The French Polynesia’s health authorities have confirmed two autochthonous dengue cases on the island Moorea. These are the first dengue cases reported on the island in four years.
The Caribbean: The dengue epidemic in Puerto Rico is still on-going with 1 028 suspected cases reported in the first two weeks of 2013, according to the latest figures from the CDC. In other regions, the Cayman Islands have reported 40 dengue cases so far this year and Barbados is seeing a recent surge in dengue cases compared to the same time period last year.
ECDC monitors individual outbreaks, seasonal transmission patterns and inter-annual epidemic cycles of dengue through epidemic intelligence activities in order to identify significant changes in disease epidemiology. Of particular concern is the potential for the establishment of dengue transmission in Europe. Before the current outbreak in the Autonomous Region of Madeira, local transmission of dengue was reported for the first time in France and Croatia in 2010. Imported cases are detected in European countries highlighting the risk of locally acquired cases occurring in countries where the competent vectors are present.
ECDC has published a technical report on the climatic suitability for dengue transmission in continental Europe and guidance for invasive mosquitoes’ surveillance.