Tiger mosquito and chikungunya in France in July 2026: record number of indigenous cases, 81 departments colonised, Île-de-France on the front line

The enhanced surveillance bulletin issued by Santé publique France on 21 July 2026 confirms it: metropolitan France is currently living through an exceptional 2026 chikungunya season. Over the surveillance period from 1 May to 21 July 2026, the country has already recorded a historic record number of indigenous cases and local transmission clusters — viral circulation that is directly established on French soil without any travel abroad. On top of this, Aedes albopictus is now established in 81 metropolitan departments as of 1 January 2026, up from 78 a year earlier. For Île-de-France, home to the largest population concentration in France on the country's most urbanised territory, this double news is not a statistic: it is a change in risk level that now affects balconies, terraces, schoolyards, nurseries and the ground floors of buildings. Here is what the bulletin says, what it concretely changes for residents of the Paris region, and how ProDeratisation steps in for individuals, condominiums, businesses and local authorities.

What the Santé publique France bulletin of 21 July 2026 says

The weekly enhanced arbovirus surveillance bulletin for metropolitan France (santepubliquefrance.fr), published every week from May to November, documents an epidemic dynamic never before observed at this point in the year for the ongoing 2026 season. Key points:

• Indigenous cases: the cumulative number over the period 1 May – 21 July 2026 exceeds the historic threshold of 2010-2024, which capped at 84 annual cases. As of the end of July 2026, several dozen clusters have already been documented by the regional health agencies (ARS), mainly in Corsica, Provence-Alpes-Côte d'Azur, Occitanie, Auvergne-Rhône-Alpes and Nouvelle-Aquitaine.
• Transmission clusters: each cluster triggers an entomological investigation within a 150-metre radius, door-to-door active case finding, targeted adulticide spraying and a public awareness campaign for residents. At this pace, the capacity of mosquito-control operators is under strain in the south.
• Imported cases: surveillance remains heavily driven by travellers returning from La Réunion (where the epidemic is still ongoing), Madagascar, the Comoros and the intertropical zone in general. A viraemic imported case in a neighbourhood colonised by Aedes albopictus can generate a local cluster in less than 15 days if nothing is done.
• 81 departments colonised on 1 January 2026 by Aedes albopictus — a gain of three departments in one year — with a steady progression northwards and westwards, along road corridors and in dense urban areas.

What you need to understand: the 2026 situation is no longer an exotic health event, it is an established public health phenomenon. The tiger mosquito is no longer a southern threat, it is a common urban animal that you will encounter in all the big cities of Île-de-France, in inner Paris as well as in the inner and outer suburbs.

Close-up of an Aedes albopictus tiger mosquito on human skin, a painful bite responsible for the transmission of chikungunya, dengue and Zika in France

Why 2026 is an out-of-the-ordinary season

Three factors explain the ongoing record.

1. A more present tiger mosquito than ever

The tiger mosquito (Aedes albopictus) is a diurnal, aggressive biter that breeds in any small stagnant water point (saucer, clogged gutter, bottle cap, children's toy, water butt, pool cover, plant pot tray). Its development cycle — egg → larva → adult — is 7 to 10 days in summer at 25-30 °C, which means that a single point of water left in a garden can produce hundreds of tiger mosquitoes per month. The tiger mosquito is now established in 81 metropolitan departments and the dynamic is accelerating northwards.

2. A heatwave in June 2026 that accelerated reproduction

The heatwave of June 2026 — daytime temperatures above 32 °C over the northern half, nighttime temperatures above 20 °C in Île-de-France — created a generational doubling effect: females lay more eggs, eggs hatch faster, adults live longer. The first storm rains that followed deposited ephemeral collections of stagnant water (trays, tarpaulins, manholes) that the July heat kept warm — ideal conditions for tiger mosquito multiplication in urban areas.

3. A viral reservoir fed by travel

The viral strain in circulation is related to the ECSA lineage (East-Central South African) which has been circulating in the Indian Ocean since 2024-2025 (La Réunion, Mayotte, Madagascar). In 2025, 82% of imported cases came from La Réunion. In 2026, this reservoir is still active, and each viraemic returning traveller in a neighbourhood colonised by Aedes albopictus can generate a local cluster in less than 15 days if bites are not prevented.

Île-de-France on the front line: why now

Île-de-France is not yet the most affected French region (that is PACA, Occitanie and Corsica), but it ticks every box for an imminent shift.

• Population density: 12.2 million inhabitants on 12,000 km², the highest density in metropolitan France. The more humans there are, the more bites there are, the more chance an imported case triggers a cluster.
• Forest cover and water points: the Forest of Fontainebleau, the Dombe ponds, the banks of the Marne and the Seine, the edges of the Canal de l'Ourcq are reservoirs of mosquitoes. The stormwater retention basins in new urban areas (Saclay, Île-de-France Est, Plaine de France) are first-class larval habitats.
• Mobility: Roissy-CDG and Orly generate massive flows of travellers from La Réunion, Mayotte, Madagascar, the West Indies, French Guiana. A viraemic passenger arriving at 8am can be bitten at noon in his garden in Montreuil, Saint-Denis or Versailles.
• Collective housing: Île-de-France concentrates 40% of the collective housing stock in mainland France. The building courtyards, the cellars with crawl spaces, the underground car parks that are poorly ventilated, the terraces with water collection are larval habitats in dense urban areas.

In practice, the ARS Île-de-France has documented since 2023 an active and established presence of the tiger mosquito in all eight Île-de-France departments. The Paris city council officialised the capital's colonisation in 2015. Vincennes, Montreuil, Saint-Denis, Boulogne-Billancourt, Nanterre, Créteil, Évry, Cergy, Pontoise, Versailles, Mantes-la-Jolie, Meaux: all municipalities of the inner and outer suburbs are now in colonised zones.

Recognising the tiger mosquito: the visual checklist

The fight starts with identification. Unlike the common mosquito (Culex pipiens), which is brown and nocturnal, the tiger mosquito is:

• Small (5-7 mm, smaller than a 1-cent coin)
• Black with white stripes on the body and legs (hence its "tiger" name)
• Active during the day, particularly early morning and late afternoon
• Very silent in flight (no high-pitched buzzing)
• Aggressive biter: it bites several times, mainly on legs and ankles

The French food safety agency ANSES has published an online identification guide, and the portal signalement-moustique.fr allows every citizen to report a suspected tiger mosquito and obtain an identification by a mosquito-control operator.

The concrete action plan for residents of the Paris region

Here is the protocol we recommend this summer 2026, in three levels of action — from individual to condominium.

Level 1 — At home and on the balcony (all residents of Île-de-France)

1. Remove stagnant water once a week, this is the most effective gesture. Empty or store: saucers, buckets, watering cans, children's games, folded tarpaulins, gutters, manholes, drain plugs. A lid on the rainwater butt.
2. Install mosquito nets on bedroom windows, particularly for infants, young children and elderly people.
3. Wear long, loose and light-coloured clothing at the mosquito's active hours (sunrise and late afternoon). Optionally impregnate the fabric with a textile repellent (permethrin).
4. Use an approved skin repellent — DEET 30-50%, icaridin 20-30%, or IR3535 depending on age and contraindications. Follow the instructions and do not apply to children under 6 months (mosquito net only).
5. Fan above the garden table: the tiger mosquito is a poor sailor, a simple draught is enough to keep it away.
6. CO₂ traps and ovitraps: for gardens and terraces, these devices complement surveillance.

Level 2 — In condominiums, businesses, public-access buildings

1. Entomological audit of common areas (cellars, waste rooms, crawl spaces, car parks, courtyards, green spaces). The mosquito-control operator identifies and treats the larval habitats.
2. Biological larvicide (Bti — Bacillus thuringiensis israelensis) in non-removable water points: manholes, damp sandboxes, fountains, gutters, ornamental ponds. Targeted at larvae, harmless to mammals, birds and fish.
3. Adulticide (ULV — Ultra-Low-Volume spraying) only on prefectural decision during a declared cluster, by an approved operator.
4. Multi-year management plan: an annual contract with a Certibiocide-approved operator costs between €150 and €600 per year for a 20-flat building, i.e. an investment of €0.10 to €0.30 per month per flat for collective peace of mind.
5. Hall display: reminder of good practices and the report number signalement-moustique.fr.

Level 3 — ProDeratisation intervention in Île-de-France

For individuals, condominiums, businesses, local authorities and property managers, ProDeratisation offers a complete package:

• Initial site diagnosis, free and within 24-48 hours in Île-de-France: identification of the species present, mapping of larval habitats, assessment of the health risk, written report.
• Targeted larvicide treatment with Bti on non-removable water points, ULV adulticide if necessary.
• Seasonal monitoring plan: monthly visits from May to October, adjusted according to rainfall and heatwave episodes.
• Coordination with ARS Île-de-France in case of suspected or confirmed case: reporting, entomological investigation, intervention in the 150-metre perimeter defined by Santé publique France.
• Occupant awareness: displays, information notes, training for caretakers and building staff.

Request a tiger mosquito diagnosis | 24/7 emergency in Île-de-France | See our mosquito-control prices

What to do in case of a bite and suspicious symptoms

Chikungunya appears 3 to 7 days after the bite with:

• Sudden fever > 38.5 °C
• Intense joint pain (ankles, wrists, knees) — hence the name chikungunya ("who bends up" in Makonde)
• Headaches, skin rash, severe fatigue

What to do: see your GP within 24 hours, mentioning the stay in a colonised area or the recent bites. Diagnosis is based on a serology (blood test) and/or a PCR. No curative treatment exists: paracetamol relieves pain, aspirin is not recommended because of the bleeding risk. Joint pain can persist for several months in 30 to 50% of patients.

For dengue, the symptoms are similar with a risk of severe form in case of a second episode. For Zika, the main risk concerns pregnant women (foetal microcephaly).

What the State is doing and what remains to be done

The effective side

• Enhanced surveillance from 1 May to 30 November, by Santé publique France, the ARS and the Interdepartmental Mosquito Control Agency (EID).
• National anti-dissemination plan for chikungunya, dengue and Zika, revised every year.
• Ixchiq vaccine (Valneva) available on prescription for travellers to risk areas, with caution in over 65s (risk of side effects).
• Vector control (LAV) free of charge within the perimeter of declared cases.

The side that is struggling

• Capacity of mosquito-control operators: the growth in the number of colonised departments (+3 per year) is not matched by a proportional increase in resources. The intervention time within a cluster's perimeter can reach 5 to 10 days in high season.
• Public communication: 60% of residents of Île-de-France do not yet know how to recognise a tiger mosquito (ARS Île-de-France survey 2025).
• Collective action: LAV only works if the private larval habitats are removed. However, the mobilisation of individuals remains low outside crisis periods.

To find out more, you can read our analysis of protection against the tiger mosquito in Île-de-France and our article on drone releases of sterile male mosquitoes, a forward-looking technique already tested in Monaco and Hérault.

Summary

The 2026 chikungunya season in metropolitan France is on track to become the most important ever documented at this point in the year. Three truths to remember for residents of Île-de-France:

• ✅ The tiger mosquito is here, and it is at home: 81 departments colonised, established presence in Paris and Île-de-France, continuous progression northwards.
• ✅ The virus is already circulating locally: indigenous cases are documented in PACA, Corsica, Occitanie, Auvergne-Rhône-Alpes and Nouvelle-Aquitaine. Île-de-France is not yet in cluster mode, but the risk of local transmission this summer is real and quantified.
• ✅ Individual and collective prevention is effective: removal of stagnant water, repellents, long clothing, mosquito nets, larvicide treatment by an approved operator. A modest investment by condominiums (€0.10 to €0.30 per month per flat) is enough to divide the risk by ten.

ProDeratisation operates 7 days a week in Île-de-France (Paris, Hauts-de-Seine, Seine-Saint-Denis, Val-de-Marne, Seine-et-Marne, Yvelines, Essonne, Val-d'Oise) for the diagnosis, treatment and monitoring of mosquito control. If you notice the presence of tiger mosquitoes in your home, garden, condominium or business, contact us: free diagnosis within 24 to 48 hours, technical report that can be attached to an approach to your building manager or town hall, rapid intervention in case of suspected chikungunya cluster.

Request a tiger mosquito diagnosis | 24/7 emergency | See our mosquito-control prices