Chikungunya outbreak in Montpellier, France, September to October 2014

Area of Science:

• Epidemiology
• Medical Entomology
• Public Health

Background:

• Aedes albopictus mosquitoes, the vector for chikungunya, have been established in southern France since 2010.
• France's chikungunya and dengue surveillance system faced challenges in 2014 due to numerous imported cases from the Caribbean.

Purpose of the Study:

• To report on the first significant chikungunya outbreak in Europe since 2007, occurring in Montpellier, France.
• To analyze the epidemiological features and control measures of this autochthonous chikungunya outbreak.

Main Methods:

• Detection and confirmation of chikungunya cases through epidemiological investigations.
• Implementation of vector control treatments in affected areas and around case-frequented locations.
• Genomic analysis to identify the chikungunya virus strain involved.

Main Results:

• An outbreak of 12 chikungunya cases (11 confirmed, 1 probable) occurred in Montpellier in October 2014.
• The primary case was linked to travel from Cameroon, and the outbreak strain was identified as East Central South African (ECSA).
• Epidemiological investigations and vector control measures successfully contained the outbreak.

Conclusions:

• The 2014 Montpellier outbreak demonstrated the real threat of chikungunya epidemics in southern Europe.
• Lessons learned emphasize the importance of robust surveillance and rapid response to vector-borne diseases.
• The ECSA strain's introduction highlights the risk posed by international travel and imported cases.