Mosquitoes, ticks and diseases such as West Nile and dengue in Spain

Key rules

• Tiger mosquito season: In most of Spain it is active from April-May to November, with the peak from July to October.
• Standing water: Emptying standing water once a week is the most effective step you can take at home.
• Dengue: Local dengue cases are rare; most are brought in by travellers.
• Ticks: Ticks occur across Spain, so check yourself after countryside walks and remove any tick at once.
• Emergencies: Call 112 if symptoms after a bite are severe.

The short version

Take simple, steady precautions. Spain has no need for alarm, but it does have tiger mosquitoes, West Nile virus in some wetlands, rare local dengue and ticks nearly everywhere. Empty standing water, screen your windows, use repellent and check yourself for ticks after time in the countryside.

Tiger mosquitoes

The tiger mosquito was first found near Barcelona in 2004. It is now established along the Mediterranean coast and on the islands: Catalonia, the Valencian Community, Murcia, the Balearic Islands and eastern Andalusia. Colonies also exist inland, in Aragon, the Madrid area, the Basque Country, Navarra, Extremadura and parts of Castilla-La Mancha, Galicia and Andalusia. The map grows every year, so check your municipality with the Ministry of Health or your regional public-health service.

It is active from April-May to November, with the peak from July to October. On the warm coast and the Balearics it can start in March and last into December. Inland and in the north the season is shorter, roughly June to October. It bites in the daytime, not only at dusk.

Dengue

You can catch dengue in Spain, but it is rare. Local cases have appeared since 2018, mainly in Catalonia, Andalusia, the Balearics and Madrid. Only a handful occur in a year, and outbreaks have been small and short. Most cases are brought in by travellers from tropical countries. The tiger mosquito is the carrier, so the home precautions below are your protection.

West Nile virus and wetlands

West Nile virus passes between birds and Culex mosquitoes from late spring to autumn. It is mainly a risk near the lower Guadalquivir marshes (Seville, Cádiz, Huelva). Cases have also been found in Extremadura, Castilla-La Mancha, the Ebro delta in Catalonia and Madrid. Human cases peak from July to October, mostly in August and September. Most infections cause no symptoms. If you live near wetlands, take extra care in summer evenings and watch for local health alerts.

Ticks

Ticks live across Spain, mainly in scrub, grazing land and woodland. Hikers, hunters and farm workers are most exposed. Three diseases are worth knowing:

• Lyme disease is concentrated in the humid north: Galicia, Asturias, Cantabria, the Basque Country, Navarra, La Rioja and northern Castilla y León. Activity runs from spring to autumn and peaks in May-July.
• Crimean-Congo fever is rare, with a few cases a year, mostly in spring and summer. It has appeared in the west and centre, including Salamanca, Ávila, Cáceres, Badajoz, Toledo, Ciudad Real and Madrid.
• Mediterranean spotted fever occurs in summer in the south, the centre and along the Mediterranean.

What to do at home

• Empty standing water weekly and cover tanks and barrels.
• Fit screens on windows and doors.
• Wear repellent and long light clothing at dusk and dawn.
• Use a bed net over an infant's cot.

Check age limits on repellents for children and pregnant women. Your town hall may run larvicide campaigns, so follow its advice. The checklist below has the full list.

If a tick bites you

Remove it quickly with fine-tipped tweezers or a tick-removal tool. Grip close to the skin and pull steadily upward. Do not twist or crush it. Disinfect the bite, wash your hands and note the date.

See a doctor at your centro de salud if the mouthparts stay in the skin. Go also if fever, headache, muscle pain, fatigue, a rash or an expanding red patch appears within about 30 days. In a Crimean-Congo area, see a doctor promptly if you get fever or bleeding. If symptoms are severe, call 112. For infants or people with weak immune systems, see a doctor earlier.

Where to get current alerts

Case numbers and affected towns change each season. Check the Ministry of Health and its alerts centre, and your region's public-health directorate. Your town hall publishes local mosquito-control campaigns.

Timeline and deadlines

• On the warm Mediterranean coast and the Balearics, mosquito activity can start early and continue late: from March into December

• Start weekly checks for standing water and fit window screens: before April-May to November, when the tiger mosquito is active in most of Spain

• Expect the most mosquitoes and take the most care: July to October

• In inland and northern areas, the mosquito season is shorter: roughly June to October

• Watch for fever, headache, muscle pain, fatigue, a rash or an expanding red patch after a tick bite: within about 30 days of the bite

Checklist

• Empty standing water once a week: plant saucers, buckets, gutters, drains, tyres, pet bowls and bird baths.

• Cover water tanks and rain barrels, and keep pools treated and covered.

• Fit mosquito screens on windows and doors, and use air conditioning or fans.

• Use repellent authorised in Spain (DEET, icaridin or IR3535), checking the age limits for children and pregnancy, and wear long light clothing at dusk and dawn.

• Put a bed net over infants' cots, and use plug-in or indoor insecticides only as directed.

• Find out whether your area is on the tiger mosquito map or near wetlands such as the Guadalquivir marshes, where West Nile occurs.

• Check for dengue or West Nile alerts for your region during local outbreaks.

• Remove a tick at once with fine-tipped tweezers, pulling steadily upward without twisting, then disinfect the bite, wash your hands and note the date.

What to watch out for

• Home tricks make tick bites worse: Oil, alcohol, heat, squeezing or twisting can leave mouthparts in the skin or harm the tick's grip, raising the risk of infection.

• Symptoms can appear weeks after a bite: Fever, headache, muscle pain, fatigue, a rash or an expanding red patch (erythema migrans) can show up days to weeks later. Note the date of the bite. If symptoms appear within about 30 days, see a doctor. Call 112 if severe.

• Crimean-Congo fever in the west and centre: Hyalomma ticks carry this disease in areas such as Salamanca, Ávila, Cáceres, Badajoz, Toledo, Ciudad Real and Madrid, with a few cases a year, mostly in spring and summer. After a bite in these areas, go to a doctor promptly if you develop fever or bleeding.

• Ticks are found across Spain: Risk is highest in rural, scrub, grazing and woodland areas, for hikers, hunters and farm workers. Lyme disease is concentrated in the humid north. Check your skin and clothing after walks in these places. Look up your region's current advice from its public-health directorate.

Frequently asked questions

Can you catch dengue in Spain, or only abroad?

Yes, dengue has been caught locally in Spain since 2018, but local cases are rare. Most cases are brought in by travellers from tropical areas, and local outbreaks have been small and short. The mosquito that spreads it here is the tiger mosquito.

Where are West Nile virus cases found in Spain?

West Nile virus occurs mainly in the lower Guadalquivir marshes of Andalusia, around Seville, Cádiz and Huelva. Cases also appear in Extremadura, Castilla-La Mancha, the Ebro delta in Catalonia and Madrid. Most infections cause no symptoms.

Which parts of Spain have the most Lyme disease from ticks?

Lyme disease is concentrated in the humid north, from Galicia and Asturias to Navarra, La Rioja and northern Castilla y León. Activity runs from spring to autumn and peaks in May-July. Crimean-Congo fever is mostly a western and central concern instead.

Does the tiger mosquito bite during the day?

Yes, the tiger mosquito also bites in daytime, not only at dusk and dawn. Use repellent and cover your skin outdoors at any hour in its season. Screens on windows and doors help indoors.