Dengue confirmed in Alpes-Maritimes: what the cluster tells us about Aedes albopictus in southern Europe
Three locally-acquired cases, one hospitalisation. Genotype matches the southeast-Asian lineage circulating since 2024. What it means for residents, travellers, and summer policy.
title: "Dengue confirmed in Alpes-Maritimes: what the cluster tells us about Aedes albopictus in southern Europe" date: "2026-04-21" updatedDate: "2026-04-23" author: "Mosticare Editorial" authorRole: "Chief Executive · Mosticare Agency" mins: 8 region: "France" alert: "Outbreak" excerpt: "Three locally-acquired cases, one hospitalisation. Genotype matches the southeast-Asian lineage circulating since 2024. What it means for residents, travellers, and summer policy." sources:
- text: "Santé publique France · Bulletin 15/2026" href: "https://www.santepubliquefrance.fr"
- text: "Institut Pasteur · DENV-2 sequence MP2026-041" href: "https://www.pasteur.fr"
- text: "ECDC · Vector-borne Disease Weekly W16/2026" href: "https://www.ecdc.europa.eu"
- text: "Gjenero-Margan et al. 2011 · Ravenna chikungunya response" href: "https://doi.org/10.2807/ese.16.36.19962-en" correctionEmail: "corrections@mosticare.org"
The question has never been whether Aedes albopictus would establish in southern Europe. It was already established. The question was whether local transmission of dengue would follow, and how quickly.
On 20 April 2026, the French public health agency (Santé publique France) confirmed three cases of dengue in residents of Cannes and Antibes who had not travelled in the preceding eight weeks. One was hospitalised with haemorrhagic presentation and has since recovered. Genomic sequencing, performed by the Institut Pasteur's Unité des Virus Émergents, matched lineage DENV-2 Cosmopolitan, the southeast-Asian strain circulating in the region since 2024.
Update · 23 April 2026: The cluster has since expanded to 14 confirmed cases across the Alpes-Maritimes department. Two hospitalisations reported; both discharged. The Hérault department (Montpellier) has separately confirmed a chikungunya cluster of 7 cases — the first of 2026 in metropolitan France outside the original Alpes-Maritimes zone.
What we know
The cluster is tightly geographic. All three initial cases lived within 600 metres of each other along a residential street with known Aedes breeding sites, specifically, a set of unmaintained ornamental planters and a shared garden cistern. Trap catches from the surrounding 2 km² returned a mean density of 42 females per BG-Sentinel per week, approximately four times the seasonal baseline.
The 14-case expansion is consistent with secondary transmission from the original breeding site, compounded by a warm April. ECDC's vector-borne disease surveillance network has upgraded the Alpes-Maritimes département to its highest alert tier.
What the reflex response gets wrong
The municipality has authorised aerial pyrethroid fogging of the affected area. This is, in our view, a response calibrated to headlines rather than to outcomes. Fogging produces a visible plume, a reassuring press conference, and a roughly 40% kill of adult mosquitoes for a period of 48 to 72 hours. It does not reach breeding sites. It does not meaningfully interrupt transmission. And it exposes an estimated 18,000 residents, several elementary schools, and a bee-keeping cooperative to a chemical whose long-term health profile remains under active review by EFSA.
The measured response is the unglamorous one: door-to-door breeding-site elimination, targeted larviciding with Bti, distribution of physical-barrier window and bed protection to households within the transmission radius, and daily trap-count surveillance until catches return to baseline. This is what Italy did in Ravenna in 2007. It worked.
What you can do · residents of the region
- Inspect and empty any standing water in your property weekly, planters, pet bowls, gutters, pool covers.
- Install fitted insect screens on bedroom windows; use a Mosticare or equivalent WHO-standard bed net.
- Avoid aerosol sprays and plug-in diffusers indoors, particularly with children or respiratory conditions in the household.
- If you develop fever with headache and muscle pain within the next three weeks, contact your GP and disclose your address.
The longer arc
France recorded its first locally-acquired dengue case in 2010. Between 2010 and 2019, the country averaged fewer than ten autochthonous cases per year. In 2022 that number exceeded sixty. In 2024, it approached two hundred. The vector is no longer arriving, it lives here. Our posture should adjust accordingly.
The 2026 season is running ahead of the 2025 baseline across all Mediterranean indicators. Trap densities are elevated. Temperatures have been consistently 1.4°C above the 10-year mean. The imported case pipeline from Southeast Asia and Latin America is higher than any previous April on record.
Mosticare will continue to cover this cluster with daily updates on the Threat Map. The regional dossier is available at mosticare.org/threat-map and will be revised as trap data, case reports, and sequencing results come in.