Chikungunya outbreak in Montpellier, France, September to October 2014.

International audienceIn October 2014, an outbreak of 12 autochthonous chikungunya cases, 11 confirmed and 1 probable, was detected in a district of Montpellier, a town in the south of France colonised by the vector Aedes albopictus since 2010. A case returning from Cameroon living in the affected district was identified as the primary case. The epidemiological investigations and the repeated vector control treatments performed in the area and around places frequented by cases helped to contain the outbreak. In 2014, the chikungunya and dengue surveillance system in mainland France was challenged by numerous imported cases due to the chikungunya epidemic ongoing in the Caribbean Islands. This first significant outbreak of chikungunya in Europe since the 2007 Italian epidemic, however, was due to an East Central South African (ECSA) strain, imported by a traveller returning from West Africa. Important lessons were learned from this episode, which reminds us that the threat of a chikungunya epidemic in southern Europe is real

Dengue and other Aedes-borne viruses: a threat to Europe?

At the beginning of the 20th century, dengue outbreaks were rather common in the Mediterranean basin. The last major epidemic on the European continent occurred in 1927/28 and predominantly affected Athens and neighbouring areas of Greece. After a first mild wave, which nearly ended with the arrival of cold weather in the winter season, a small number of cases continued to occur through the winter and spring, increasing dramatically in August 1928 [1-3]. It is conceivable that both the virus and its primary vector, the Aedes aegypti mosquito, survived the winter in the city, inside heated houses. Serological surveys detected neutralising antibodies to different dengue virus (DENV) serotypes in samples of individuals living in Athens in that period [4,5]. Some time after this severe outbreak, with 1,000 to 1,500 deaths, both dengue and its primary vector 'abandoned' the European continent

Public health responses to and challenges for the control of dengue transmission in high-income countries: four case studies

Dengue has a negative impact in low- and lower middle-income countries, but also affects upper middle- and high-income countries. Despite the efforts at controlling this disease, it is unclear why dengue remains an issue in affluent countries. A better understanding of dengue epidemiology and its burden, and those of chikungunya virus and Zika virus which share vectors with dengue, is required to prevent the emergence of these diseases in high-income countries in the future. The purpose of this review was to assess the relative burden of dengue in four high-income countries and to appraise the similarities and differences in dengue transmission. We searched PubMed, ISI Web of Science, and Google Scholar using specific keywords for articles published up to 05 May 2016. We found that outbreaks rarely occur where only Aedes albopictus is present. The main similarities between countries uncovered by our review are the proximity to dengue-endemic countries, the presence of a competent mosquito vector, a largely nonimmune population, and a lack of citizens’ engagement in control of mosquito breeding. We identified important epidemiological and environmental issues including the increase of local transmission despite control efforts, population growth, difficulty locating larval sites, and increased human mobility from neighboring endemic countries. Budget cuts in health and lack of practical vaccines contribute to an increased risk. To be successful, dengue-control programs for high-income countries must consider the epidemiology of dengue in other countries and use this information to minimize virus importation, improve the control of the cryptic larval habitat, and engage the community in reducing vector breeding. Finally, the presence of a communicable disease center is critical for managing and reducing future disease risks