Neglected tropical diseases

Dengue cases in Madeira, Portugal

Credit: Creative Commons/Muhammad Mahdi Karim

17 October 2012 | Geneva -- On 4 October 2012, the Ministry of Health of Portugal reported 2 laboratory-confirmed cases of dengue to WHO in patients from the island of Madeira, Portugal.

This is the first time autochthonous cases have been reported on the island, triggering active case finding.

A total of 18 laboratory-confirmed cases of DEN-1 virus and a further 256 probable cases have been recorded. Of the laboratory-confirmed cases, 8 are male and 10 are female; the youngest case is 1 year old and the oldest case is 82 years old. Of the 256 probable cases, 26 have been hospitalized. No fatal cases have been reported.

Analysis of the genome sequence of samples taken from probable cases indicates high similarity with DEN-1 viruses circulating in the Bolivarian Republic of Venezuela and Colombia, strongly suggesting transmission of Latin America origin. The analysis was performed at the National Institute of Health in Lisbon, Portugal.

Aedes aegypti, a competent vector of dengue, has been identified on the island since 2005 and its density has increased recently.

Local authorities are implementing measures to prevent the establishment of the vector in the island, namely disinsection campaigns, reinforcement of vector surveillance and traps, monitoring of ports and airports, and public education and information campaigns.

The vector has not been identified in Porto Santo, the other inhabited island of the Archipelago.