Ticks and Lyme disease in France in July 2026: why Île-de-France is not spared and how to protect yourself

The summer of 2026 is here, and the forests of Île-de-France — Fontainebleau, Rambouillet, Senart, Chevreuse, Meudon, Forêt de Carnelle — see thousands of hikers, trail runners, dog walkers, riders, mushroom pickers and holidaymakers heading into the undergrowth every weekend. This is precisely the peak activity period for the Ixodes ricinus tick, the n°1 vector of Lyme borreliosis in France. According to the 2024 report from Santé publique France and the 2025 prevention sheet from the Haute Autorité de santé (HAS), more than 39,000 cases of Lyme borreliosis are diagnosed every year in the country, and the 2026 season is shaping up to be particularly heavy because of the hot and humid weather that characterises the summer. Contrary to a common misconception, Île-de-France is not spared: the tick is present in all the wooded massifs of the region, but also in 30% of private gardens in peri-urban areas. Here is what you need to know to recognise, remove, monitor and report a bite, and how ProDeratisation can support owners, building managers and local authorities to reduce exposure on their land.

The tick, a mite that is anything but harmless

The tick is not an insect: it is a blood-sucking mite of the Ixodidae family. In metropolitan France, the dominant species is Ixodes ricinus, commonly called the "sheep tick". Its life cycle has 3 successive stages — larva (6 legs), nymph (8 legs) and adult (8 legs) — and it takes a blood meal at each stage, on a different host (rodent, deer, bird, dog, human). The nymphal stage, tiny (1 to 3 mm) and hard to see, is responsible for the majority of human infections, precisely because it goes unnoticed.

Good to know: the tick does not "jump" and does not "fall" from trees. It practices questing: positioned on low vegetation (tall grass, ferns, brushwood, up to 1.5 m high), it attaches itself to the host that brushes against the support. This is why staying on marked paths greatly reduces the risk.

The Ixodes ricinus tick becomes active as soon as the temperature rises above 7°C and humidity is sufficient: in France, the activity season runs from March to November, with a main peak in May-June and a second peak in September-October. But with the heatwaves interspersed with thunderstorms that summer 2026 is bringing, activity remains high in July-August, the period when walks in the forest and barbecues in the garden are most frequent.

Lyme, tick-borne encephalitis, and other transmitted diseases

The Ixodes ricinus tick is a competent vector for several pathogens:

• Borrelia burgdorferi (and related species) → Lyme borreliosis: by far the most frequent in France, > 39,000 cases/year diagnosed (Santé publique France 2023-2024 data).
• TBE virus (Tick-Borne Encephalitis) → tick-borne encephalitis: present endemically in eastern France (Alsace, Lorraine, Alps), with circulation also identified in Haute-Savoie and the Jura. Northern Italy and German-speaking Switzerland are now well-documented risk areas. The TBE virus is not yet endemic in Île-de-France, but tourist mobility and climate change are extending the area of circulation.
• Anaplasma phagocytophilum → anaplasmosis (fever, chills, aches).
• Babesia divergens → babesiosis (pseudo-malaria).
• Rickettsia spp. → various rickettsioses, including Mediterranean spotted fever in the south.

5% of ticks are estimated to carry a pathogen transmissible to humans in high-endemicity zones, and the risk of Borrelia transmission increases significantly after 36 to 48 hours of attachment. This is precisely the window on which the entire prevention strategy rests: spot it fast, remove it fast, monitor for 4 weeks.

Summer undergrowth, a typical walking spot where the Ixodes ricinus tick practices questing on tall grass and ferns

What to do in case of a bite: the 6-step method

1. Remove the tick immediately with a tick remover

This is the #1 move. The longer the tick stays embedded, the higher the risk of transmission.

• Use a tick remover (sold in pharmacies, parapharmacies, hiking shops) — not regular tweezers, not flat-nose pliers, not bare fingers.
• Slide the slot of the tick remover under the tick, as close to the skin as possible, without pulling on the body of the mite.
• Perform a slow rotation and a gentle pull (the tick remover is designed to "unscrew" the rostrum without breaking it).
• Disinfect the area afterwards with an antiseptic (chlorhexidine, Biseptine, povidone-iodine).
• Never use ether, alcohol, varnish, oil, petroleum or heat to stun the tick: these products cause regurgitation that increases the risk of transmission.

Common mistake: pulling straight with tweezers. This often breaks the rostrum, which remains lodged in the skin and forms a persistent inflammatory granuloma, with a local infectious risk.

2. Identify the tick (optional but useful)

Photographing the tick (size, colour, scutum pattern) before throwing it away helps, in case of symptoms, the doctor to guide the diagnosis. The tick can also be sent to the CiTIQUE / INRAE programme via the Signalement tique app (signalement-tique.fr), which maps tick populations in France and improves epidemiological surveillance.

3. Monitor the area for 4 weeks

Erythema migrans — a red ring-shaped patch, gradually spreading around the bite point, non-pruritic, sometimes multi-annular — is the pathognomonic sign of the early stage of Lyme borreliosis. It appears in 3 to 30 days (median 7-14 days) after the bite in 60 to 80% of infected patients. Any red patch that spreads after a bite should prompt a consultation within 24 to 48 hours.

4. Know the other warning symptoms

In the absence of erythema migrans, or in addition, consult if within 4 weeks you develop:

• Fever, chills, night sweats
• Unusual and persistent fatigue, feeling of a "crash"
• Joint pain (knee, shoulder, ankle), migratory
• Neurological pain (sciatica, trigeminal neuralgia, facial paralysis)
• Cardiac disorders (palpitations, malaise, chest pain) — rare but urgent

5. Consult without delay

If you see a suspicious sign, see your GP first, or an international vaccination centre when travelling. Diagnosis is based on clinical examination (erythema migrans) and, at the secondary stage, on a blood serology (Elisa + Western Blot confirmation). Treatment is a short antibiotic course (doxycycline 10 to 21 days, or amoxicillin in children and pregnant women), very effective when started early. No routine antibiotic prophylaxis after a simple bite (HAS 2025 recommendation), but on a case-by-case basis depending on the area, the duration of attachment and the tick species.

6. Report the bite

Be sure to report any bite via the Signalement tique app (CiTIQUE / INRAE): this data feeds the national map of tick populations and helps researchers anticipate the geographical spread of borreliosis and tick-borne encephalitis (TBE).

Walker in the forest in summer: covering and light-coloured clothing, the best shield against ticks even before repellent

Protecting yourself before and during the outing

For hikers, walkers and trail runners

• Stay on marked paths and avoid tall grass, ferns, brushwood at the edge of the trail.
• Covering and light-coloured clothing: long trousers, long sleeves, high socks, closed shoes. Tuck your trousers into your socks: it's a classic image, but it works.
• Skin repellents based on DEET 30-50%, icaridin 20% or IR3535 on exposed skin areas (read the leaflet, avoid during pregnancy and in young children, contraindicated under 2 years).
• Mutual inspection on return: look carefully at the warm areas — armpits, elbow creases, behind the knees, scalp (especially in children), groin, under the hair, navel, genitals. The nymph is tiny (size of a pinhead) and easy to miss.
• Shower within 2 hours of getting home: it removes ticks not yet attached and offers an ideal moment for body inspection.
• Wash clothes at 60°C minimum (ticks survive a 30-40°C cycle) or tumble-dry for 1 hour on high heat, or place in sealed bags in the freezer for 24-48 hours.

HAS 2025 note: permethrin applied to clothing (spray or pre-impregnated clothing) is no longer recommended for the general population in France due to potential toxicological risks. Prefer AMM skin repellents and mechanical measures.

For dog and cat owners

• Inspect the coat after each outing, focusing on the warm areas: armpits, inner thighs, ears, neck folds, base of the tail.
• External antiparasitics recommended by your vet: collars (Scalibor, Seresto), pipettes (Frontline, Advantix, Bravecto), tablets (Bravecto, NexGard). Be aware of the toxicity of some products for cats (especially permethrin): read the leaflets carefully.
• Monitor symptoms in the animal: lethargy, lameness, fever, loss of appetite. Consult the vet quickly. Dogs can also develop canine borreliosis (fever, arthritis, glomerulonephritis).

For owners of a garden, park or wooded land

• Mow lawns regularly, clear brush at the edges, prune hedges in contact with living areas.
• Create a dry barrier between the wooded area and the lawn: gravel strip, wood chips, paving slabs at least 1 m wide, which slows the migration of ticks towards terraces and play areas.
• Remove rodent shelters (woodpiles, dead leaves, compost at the edge of the garden): rodents are the main hosts of larvae and nymphs.
• Limit access for cervids (roe deer, deer) by fencing off sensitive areas: they are the adult hosts that amplify populations.
• Treat pets (dogs, cats) continuously, especially in rural and peri-urban areas.

The special case of Île-de-France

Contrary to a common misconception, Île-de-France is not a "tick-free" zone. Forests cover ~25% of the regional territory and host established populations of Ixodes ricinus:

• Forêt de Fontainebleau (Seine-et-Marne): 25,000 ha, one of the historical hotspots of Lyme borreliosis in Île-de-France. Very busy trails (hikers, climbers, mountain bikers, horse riders).
• Forêt de Rambouillet (Yvelines): 14,000 ha, very favourable environment (beech woods, oak woods, ponds).
• Forêt de Sénart (Essonne / Val-de-Marne): 3,000 ha, heavily used by walkers from the Paris metropolitan area.
• Forêt de Meudon and forêt de Fausses-Reposes (Hauts-de-Seine): very busy urban massifs on weekends.
• Forêt de Chevreuse (Yvelines): classified valley, family walks.
• Forêt de Carnelle (Val-d'Oise): Parisis massif, popular.
• Forêt domaniale de Notre-Dame (Val-de-Marne, Seine-et-Marne, Essonne): large massif, schools, equestrian centres.
• Urban parks and private gardens: rodents (rats, wood mice, voles) maintain tick populations, and 30% of bites documented in France occur in the family garden, without a forest walk.

The spread of tick-borne encephalitis (TBE) is closely monitored by the ARS: to date, the virus is endemic in eastern France (Alsace, Lorraine), but circulation in rodents has been documented sporadically in Bourgogne-Franche-Comté, and an extension to Île-de-France cannot be ruled out in the next 5 to 10 years. This is why the prevention measures detailed above concern all Île-de-France residents, not just keen hikers.

When to call on ProDeratisation

Our job is risk management for parasites and vectors. For the tick / Lyme problem, we mainly intervene upstream of exposure, supporting owners of wooded estates, building managers, green space managers, farmers, golf courses, equestrian centres, leisure centres, holiday camps and local authorities:

• Tick risk assessment: mapping of questing areas, identification of hotspots (edges, clearings, tall grass, deer areas), assessment of exposure risk for users.
• Integrated management plan: maintenance schedule (mowing, brush clearing, pruning), creation of dry barriers, management of rodent populations (reservoirs), treatment of pets.
• Reasoned deratisation of areas where rodents maintain the Borrelia cycle (wood mice, voles, rats).
• Communication protocol: signage, marked trails, user and child information (camps, leisure centres).
• Setting up veterinary and medical partnerships for tick reporting (CiTIQUE / INRAE) and safe removal on site (tick remover kit from the pharmacy, even a tick first-aid kit provided on sites open to the public).
• Training: awareness-raising for staff (forest rangers, sports educators, camp leaders, teachers, municipal employees) in the removal method and post-bite monitoring.

For individuals, we also provide advice on garden design and rodent shelter management. For the regulatory framework for pest control and owner liability, see our article on mandatory deratisation in condominiums and restaurants and our guide on professional deratisation prices in 2026.

To put the tick issue in the broader summer context of pest proliferation in summer 2026, see also our dossier deratisation and heat: why rodents are swarming this summer, as well as our articles on rats in the city and their proliferation and rats in buildings when bins are poorly managed.

For other vector risks active in Île-de-France at the same time, see our dossier West Nile virus: first indigenous case in France, July 2026 and our analysis tiger mosquito and chikungunya: record cases in July 2026.

In summary

• ✅ Summer 2026 is a peak activity period for the Ixodes ricinus tick in France: forests of Île-de-France, gardens, parks, hiking trails.
• ✅ Lyme borreliosis affects more than 39,000 people/year in France, with an erythema migrans in 60-80% of cases. Tick-borne encephalitis (TBE) is endemic in the East and is spreading.
• ✅ The key move: tick remover + gentle rotation within 36 hours, never ether, alcohol, oil or heat.
• ✅ Covering and light-coloured clothing, DEET 30-50% or icaridin repellents, shower within 2 hours, wash clothes at 60°C.
• ✅ 30% of bites occur in the private garden: mow, clear brush, manage rodents, create a dry barrier between forest and home.
• ✅ External antiparasitics for dogs and cats (vet), systematic inspection on return.
• ✅ Monitor for 4 weeks, consult at the slightest erythema migrans, spreading rash, fever or joint pain.
• ✅ Report the bite on signalement-tique.fr (CiTIQUE / INRAE) to improve national surveillance.

The tick risk is not a subject for alarmism but a subject of active vigilance, especially in summer. A post-walk inspection and a tick remover in the family medicine cabinet are enough to avoid 95% of complications. For owners, building managers, natural or leisure site managers who want to set up a tick management plan on their land, ProDeratisation operates throughout Île-de-France (Paris, Hauts-de-Seine, Seine-Saint-Denis, Val-de-Marne, Seine-et-Marne, Yvelines, Essonne, Val-d'Oise) for diagnosis, advice and risk management.

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