ticks and the diseases they transmit Ticks have become a growing public health concern, both in Spain and other countries. A picnic, a hike, or simply walking the dog through tall vegetation can be enough to end up with a tick attached to your skin. And while most bites don't result in anything serious, some can lead to serious infections if not treated promptly.
Know well What are ticks, where are they found, what diseases can they cause, how to detect them, and how to prevent their bites? It's key to enjoying the outdoors with peace of mind. Throughout this article, we'll review in detail everything you need to know: from Lyme disease and Crimean-Congo hemorrhagic fever to other infections such as babesiosis, anaplasmosis, ehrlichiosis, and Rocky Mountain spotted fever, as well as practical protective measures for people and pets.
What are ticks and why do they matter?
ticks are small parasitic mites of the arachnid familyTherefore, they are more closely related to spiders than to insects. They have eight legs in their adult stage and feed exclusively on the blood of warm-blooded animals: mammals (including humans), birds, and, to a lesser extent, other vertebrates.
Their size can vary greatly: an unfed tick typically measures between 3 and 5 mmHowever, after a substantial blood meal, its volume can increase more than tenfold, taking on a rounded, swollen, and lighter-colored appearance. The color also varies depending on the species and the degree of feeding, ranging from light shades to reddish-brown or dark brown.
There are hundreds of tick species in the worldAnd not all of them bite people or transmit pathogens. Some specialize in certain wild animals, while others are better suited to pets or livestock. In the United States, for example, there are multiple species distributed throughout the country, while in Spain, some, such as those of the genera Ixodes or Hyalomma, predominate and are of great importance to public health.
Ticks wait for their hosts in areas with tall grass, scrubland, leaf litter, roadsides, parks and gardensThey do not usually fall from trees, as is sometimes believed, but are located in vegetation at low height and get caught when an animal or person passes by.
Reasons for concern: What real risk do stings pose?
The main problem with ticks is not so much the bite itself, which often goes unnoticed, but their ability to to transmit viruses, bacteria and protozoaBy feeding on an infected animal, they can acquire various pathogens and, in a subsequent feeding, pass those germs on to another victim.
In humans, tick bites can cause anything from mild and temporary discomfort to serious, long-lasting, and even life-threatening health problems. Among the most relevant tick-borne diseases are:
- Lyme's desease (Lyme borreliosis)
- Rocky Mountain spotted fever and other rickettsial diseases
- ehrlichiosis
- anaplasmosis
- babesiosis
- tularemia
- tick-borne encephalitis (ETG)
- Crimean-Congo haemorrhagic fever
- Alpha-gal syndrome (red meat allergy after a tick bite)
In Spain, the ones that are currently of greatest concern due to their impact or their emerging nature are Lyme disease and Crimean-Congo hemorrhagic feverIn the United States, the Centers for Disease Control and Prevention (CDC) have observed a dramatic increase in Lyme disease casesFrom about 12.000 reported cases per year in 1995 to more than 63.000 in 2022, estimating that the real figure could be closer to 476.000 annual infections.
Something similar happens in Spain with the tick bites recordedIn regions like Valencia, for example, their numbers have increased sixfold in the last five years. Factors such as climate change, with milder winters and longer warm seasons, allow ticks to be active for more months, bringing forward their activity season from May to April and even remaining active with unusually high temperatures in winter.
When, where, and who is most at risk of being stung
Ticks are especially active when temperatures are mild or warm. In general, Most bites occur between April and SeptemberHowever, in years with mild winters, the risk period may extend to late winter and early autumn.
In Spain, the risk is concentrated mainly in rural and mountain areasIn areas with wildlife and livestock, the risk is lower in urban environments, although isolated cases can occur if a tick is carried by an animal (for example, a dog, a cat, or a hiker returning from the countryside).
In Spain, Lyme disease is most frequently detected in the northern part of the Iberian Peninsula, especially in Asturias and GaliciaAlthough cases have been reported in virtually all autonomous communities, Crimean-Congo hemorrhagic fever has been described mainly in areas such as Salamanca and Extremadura, without ruling out possible underreporting in other areas.
There are profiles that are especially exposed because They spend more time outdoors in habitats where ticks are abundant:
- Hikers, campers and mountaineers
- People who work in agriculture, gardeners, foresters
- Hunters, rural guards and livestock farmers
- Residents of peri-urban areas with abundant vegetation and wildlife
- Children playing in parks with long grass or scrubland
In the United States, it has been observed that the expansion of the suburbs and the presence of deer Near homes, they increase contact between people and ticks, since deer are a key host for many tick species and contribute to their spread.
What happens when you get bitten by a tick?
The most treacherous thing about a tick bite is that, often, It doesn't hurt or sting at the momentThe tick attaches itself to the skin using its mouthparts, releases anesthetic and anticoagulant substances, and can remain attached from hours to several days.
If the tick is infected with a pathogen, it can transmit it. after a certain feeding timeIn the case of Lyme disease, for example, it is estimated that the tick must remain attached to the skin for 36 to 48 hours or more for the Borrelia bacteria to be transmitted. If the tick is removed within the first 24 hours, the likelihood of infection decreases significantly.
After a bite, there is a risk of getting sick, but generally speaking it is quite lowEven so, it is recommended to monitor for about four weeks for any symptoms consistent with a tick-borne disease, such as fever, severe malaise, muscle pain, or an unusual skin rash.
If in doubt, especially if a target-shaped rash, persistent fever, severe headache, or any other striking symptoms appear after being in a risk area, it is essential to seek medical advice. consult with a health professional to assess the need for testing or treatment.
How to safely remove a tick
If you find a tick attached to your skin, the priority is remove it as soon as possible and correctlyThe shorter the time the tick has been attached, the lower the risk of pathogen transmission. To remove it, it is recommended to use a tick removal device or fine-tipped tweezers.
The recommended procedure is as follows, always with firm and smooth movements:
- Place the tweezers as close to the skin as possible, grasping the tick by the head or mouthparts, never squeezing the abdomen.
- Pull upwards steadily and perpendicular to the skin, without twisting or shaking.
- Try to remove the tick whole. If it breaks off and part of the mouthparts remains in the skin, you can try to remove the rest with tweezers; if this is not easy, it is best to leave it and consult a doctor.
- Once removed, thoroughly clean the sting area and your hands with water and soap or alcohol.
It is very important Do not use home remedies such as oil, petroleum jelly, rubbing alcohol, kerosene, applying heat (matches, cigarettes), or pulling with your fingers. These maneuvers can irritate the tick and encourage it to release more saliva or intestinal contents, increasing the risk of pathogen transmission.
After removing it, it may be useful Preserve the tick in a jar with slightly damp paperThis information can aid in diagnosis if illness develops. It's also advisable to note the date and location of the bite on the body and observe for any suspicious signs or symptoms over the following weeks.
When to see a doctor after a tick bite
Although most of the time nothing happens, it is advisable contact a healthcare professional Yes, in the days or weeks following the bite, symptoms such as the following appear:
- Fever, chills, or a severe feeling of general malaise
- Severe or persistent headache
- Noticeable muscle or joint pain
- Pronounced fatigue that cannot be explained by other reasons
- Appearance of a skin rash, especially if it is a red patch that spreads or has a "bull's-eye" appearance
- Nausea, vomiting, abdominal pain, or other digestive symptoms after the sting
- Irregular heartbeat, palpitations, or difficulty breathing
- Tingling, numbness in arms or legs, facial paralysis, or other neurological signs
In the presence of symptoms consistent with a tick-borne disease, doctors may request blood tests To detect antibodies against specific pathogens or to initiate antibiotic treatment based on clinical presentation and exposure history. It's important to note that antibodies can take weeks to appear, so a test performed too early may produce a false negative.
For this reason, especially in the initial stages of Lyme disease or other infections, It is preferable not to delay treatment when clinical suspicion is high. Early intervention is usually associated with faster recovery and less risk of long-term sequelae.
Lyme disease: the main protagonist
Lyme disease is the most common tick-borne infection in many regions of the worldIt is caused by bacteria of the genus Borrelia (such as Borrelia burgdorferi) and in Europe also by other related species. In Spain and much of Europe, it is mainly transmitted by ticks of the genus Ixodes; in the United States, the deer tick (Ixodes scapularis) and related species are the most implicated.
This disease can affect multiple organs and systemsSkin, nervous system, joints, heart, and muscles. It's not simply an infection that heals and is forgotten; in some cases, if not treated properly or if diagnosis is delayed, it can leave lasting and very debilitating consequences.
Who can get it and how is it transmitted?
Anyone who spends time in environments with grass, forests or scrubland In areas where infected ticks are present, anyone can contract Lyme disease, regardless of age. Tens of thousands of cases have been reported in the United States since reporting became mandatory, and significant underreporting is known to exist.
Ticks acquire the Borrelia bacteria by feeding on small infected mammals or birdsLater, when they feed on another host (person or animal), they can transmit the bacteria if they remain attached long enough. It is estimated that, generally, the tick must be attached for a certain period of time. more than 36 hours so that transmission is likely.
Lyme disease It is not contagious between peopleIt is not transmitted through direct contact or respiratory droplets. Mother-to-child transmission during pregnancy is very rare. It is also not transmitted through contact with dogs or other infected animals, although these can bring ticks into the home.
Initial symptoms and early stages
Lyme disease symptoms usually appear between 3 and 30 days after the bitealthough sometimes they can take longer. In the first phase, general symptoms are common and can be confused with the flu or a viral infection:
- Fever and chills
- Headache
- Intense fatigue
- Muscle and joint pain
- Swollen lymph nodes
The most typical sign, although not always present, is a skin rash called erythema migransIt usually appears near the bite site as a red patch that gradually expands, sometimes with a central clearing that gives it a bull's-eye or target-like appearance. It is estimated that up to 80% of people with Lyme disease may develop some type of rash, but the classic target rash only appears in about 20% of cases.
Late manifestations and possible sequelae
If Lyme disease is not diagnosed or treated in its early stages, Symptoms may appear weeks, months, or even years later of the sting. Late complications include:
- Arthritis, especially in large joints like the knee, with recurring pain and swelling
- Heart problems, such as rhythm disturbances or conduction blocks
- Involvement of the central or peripheral nervous system: meningitis, nerve inflammation, facial paralysis, tingling, numbness
- Chronic fatigue and other persistent symptoms that can be very debilitating
One of the major challenges of Lyme disease is that It is not always easy to diagnoseThis is especially true when the assessment is made some time after the acute phase and without a typical rash or a clearly identified bite. Indirect diagnoses based on a combination of symptoms, exposure history, and serological tests, which are not perfect, are often used.
This diagnostic difficulty has led to the use of [the following terms] in some forums. non-validated diagnostic methodsThis leads to overdiagnosis and complex situations for both doctors and patients. It is difficult to rule out Lyme disease in people with debilitating chronic conditions when they are convinced they have had it, and it is not always easy to prove this objectively.
Lyme disease testing and treatment
The most common diagnostic tests are blood tests aimed at detecting antibodies against Borrelia. Because these antibodies take time to develop, tests may be negative if they are performed too soon after the bite or if the disease is in a very early stage.
For that reason, in both humans and dogs, healthcare professionals can choose to begin antibiotic treatment Before all the tests are available, diagnosis is based on symptoms, examination, and the presence of a recent bite in a risk area. When an appropriate antibiotic is administered in the early stages of the disease, most people recover quickly and completely.
If treatment is delayed, decreases the probability of a complete cure and increases the risk of persistent effects. Lyme disease is rarely fatal, but it can lead to a chronic condition with symptoms that last for a long time and seriously affect quality of life.
Crimean-Congo hemorrhagic fever and other serious diseases
In addition to Lyme disease, there is particular concern in Spain about Crimean-Congo hemorrhagic feverIt is an infection caused by a virus transmitted by ticks of the genus Hyalomma. Unlike Lyme disease, this is a viral illness with a mortality rate that can reach 40% in some outbreaks.
Initial symptoms include high fever, dizziness, vomiting, severe headacheEye and neck discomfort, and intense back and leg pain are common symptoms. Later, hemorrhaging and serious damage to multiple organs may occur. Importantly, this disease, in addition to being transmitted by tick bites, can also be transmitted by other means. to become infected between people through contact with blood or other fluids from an infected patient.
Several cases have been identified in Spain since 2016 and it is considered a emerging diseaseThese cases are likely to increase in the coming years. Therefore, the national vector-borne disease plan has focused on monitoring these cases and improving detection.
Other relevant diseases in different parts of the world include Rocky Mountain spotted feverEhrlichiosis, anaplasmosis, and babesiosis are also common illnesses. Rocky Mountain spotted fever, for example, can be contracted throughout much of the United States and is potentially fatal if left untreated. It is characterized by fever, headache, muscle pain, nausea, vomiting, abdominal pain, and a distinctive rash that usually appears a few days after the fever begins.
La anaplasmosis and ehrlichiosis They share many symptoms: fever, general malaise, muscle aches, headaches, chills, digestive discomfort, and, in some cases, skin rashes. Symptoms usually appear 1 to 2 weeks after the bite, and their combination varies from person to person. These illnesses are also treated with specific antibiotics, and again, early detection is crucial.
Tick-borne diseases in dogs and cats
Ticks are not only a problem for humans, they can also affect pets. Dogs are particularly vulnerable to certain tick-borne diseases, including Lyme disease.
In dogs, typical symptoms of Lyme disease include limp due to joint inflammationFever, lethargy, and loss of appetite are common symptoms. In some cases, they can develop severe, life-threatening kidney disease. Therefore, in high-risk areas, it is recommended that dogs undergo annual screening tests, even if they appear healthy.
To reduce the risk to pets, it is advisable to consult how to remove ticks in cats:
- Check the dog frequently, especially after walks in the countryside: neck, ears, eyelids, tail, armpits, groin and between the toes.
- Prevent the animal from wandering around areas heavily infested with ticks when it is possible.
- Use antiparasitic products throughout the year: pipettes, oral tablets or tick collars, always under the advice of the veterinarian.
There are also Lyme disease vaccines for dogsAlthough not for cats. The veterinarian will assess whether vaccination is advisable based on the risk in the area and the animal's lifestyle. In the case of cats, Lyme disease is much less common, and their susceptibility is still being researched. However, if the cat goes outdoors, it is recommended to maintain protective measures similar to those for dogs, since ticks they carry can be transferred to people and transmit other diseases.
It is important to clarify that, contrary to what one might think, the The risk to people does not come "from the dog" itselfbut rather the possible presence of ticks in the environment. A dog well protected with collars or antiparasitic treatments usually suffers fewer bites, and many of the species involved in Lyme disease or Crimean-Congo hemorrhagic fever don't even affect dogs, although they do affect other animals and humans.
How to prevent tick bites
The best way to avoid problems is minimize the likelihood of being stungWhen going to risky areas (forests, fields with tall grass, little-used paths, rural areas…), it is advisable to follow a series of simple recommendations:
- Avoid, if possible, walking through dense bushes, tall grass or areas heavily covered with dry leaves.
- Walk the center of the trailsavoiding touching the edges and vegetation.
- Wear light-colored clothing to better see if any ticks are climbing onto your clothes.
- Wear long pants, long-sleeved shirts and closed shoes; tuck the bottom of your pants into your socks and your shirt into your pants to make it harder for ticks to access your skin.
- Wear a hat if you are going to walk through undergrowth where there may be ticks that can climb up your clothes to your head.
In addition to the physical barrier provided by clothing, the following are very useful: proven insect repellentsProducts containing DEET, picaridin, or other repellents registered with regulatory agencies (such as the EPA in the United States) are effective in reducing the number of bites. Products containing 0,5% permethrin are also used to treat clothing and equipment: in this case, they are applied to fabrics, not skin, and have the advantage of killing ticks and insects that come into contact with the garment.
It's fundamental follow the label instructions For each product: use the minimum amount necessary, do not reapply unless needed, avoid contact with eyes and mucous membranes, and take special care with children (do not apply directly to their hands, do not use very high concentrations of DEET, etc.). Repellents with vegetable oils (citronella, geranium, cedar, soy, lemongrass, etc.) also exist, but there is less data on their long-term effectiveness and safety.
After spending time outdoors, it is recommended to consult How to get rid of fleas and ticks in your home:
- Taking off your clothes as soon as you get home, Wash it and dry it at a high temperature to kill any ticks.
- Carefully check your body in front of a mirror: scalp, behind the ears, neck, armpits, waist, groin, behind the knees and between the toes.
- Also check on children and pets that have been playing outside.
- If you find a tick walking on your skin but it hasn't attached yet, you can remove it without much concern.
There is not, to this day, one vaccine authorized to prevent Lyme disease in people in the United States or in Spain. Therefore, the combination of physical protection, repellents, and thorough post-outing checks remains the most effective tool for minimizing risk.
Ultimately, living with ticks is unavoidable in many areas, but with good information, routine checks, appropriate clothing, the prudent use of repellents, and monitoring for symptoms after a bite, It is perfectly possible to continue enjoying the countryside, parks, and our pets. keeping the risk of diseases transmitted by these small parasites under control.
