This year’s post is an updated version of our previous post with some new and interesting links, including one to a lab in Germany testing ticks for pathogens.
Every spring, or sometimes even earlier, ticks pose an urgent problem for us, and not only in Switzerland. Instead of offering my annual “Tick Season Ahead” presentation, I thought a more detailed post on ticks can easily be shared. And I really want to share this – information, that is hard to get by, either because it is incorrect or specific to the American tick. So this post will talk about the tick type you come across in Switzerland.
Most of you will have heard something about ticks, maybe you recognise the term “Lyme Disease”, you might even be immunised against Tick Borne Encephalitis, TBE. But many questions remain unanswered. Or answered incorrectly or insufficiently, even amongst physicians. A 2013 study published by the Independent Institute of Medicine (IOM) showed many misconceptions and misunderstandings about Lyme Disease amongst medical professionals. The most common misconceptions were:
- Blood tests are unreliable. Correct is: the immune response takes time and the IgG-antibody test is often negative in the first four to six weeks after a tick sting; that doesn’t mean it’s unreliable though. In late stages of Lyme Disease, seronegativity, i.e. negative blood results, is very rare.
- Patients with long-term symptoms only have IgM-antibodies. Correct is: immunoglobulin M is the first immunoglobulin produced in the immune response. An increased level therefore indicates an early phase of Lyme Disease and specific IgM tests only make sense in early stages of Lyme Disease. Should patients with a four or six week long history have isolated increased IgM levels, these are likely to be false-positive.
- Positive antibody tests after antibiotic treatment are a sign of insufficient treatment. Correct is: levels of antibodies can be elevated even years after the infection and are not considered a sign of a persisting infection.
- Lyme Disease is a clinical diagnosis. Correct is: there is only one symptom that is specific to Lyme Disease and that is the “Bull’s Eye” (which only approx. 40% develop).
- Lyme Disease can be fatal. Correct is: despite its potential damage to the heart or the brain, Lyme Disease is very rarely fatal.
- If symptoms persist after antibiotic treatment, treatment must be continued. Correct is: a continuation of antibiotic treatment is only rarely required, in most cases 2 to 4 weeks are sufficient. Studies showed that continued treatment provides no additional benefits.
The fact that physicians often base their diagnosis of Lyme Disease on isolated symptoms other than the “Bull‘s Eye” and that diagnostic serology is often ignored based on “insufficient validity of the tests” was another major concern for the experts.
So, let’s look at that “American” versus the “Swiss” tick. Deer ticks, sometimes also called black-legged ticks, or by their biological name, Ixodes scapularis, are a hard-bodied tick type primarily living in the eastern and northern parts of the US. They carry the pathogens for a number of diseases, some of which can also be transmitted to humans, the most “famous” one being Lyme Disease. Lyme Disease in German is called Borreliose or Lyme-Borreliose, based on the pathogen causing it, a bacteria of the name borrelia burgdorferi. The tick itself is simply a “vector”, a carrier of the pathogens.
Externally, deer ticks and their European counterparts, Ixodes ricinus, “Zecke” or “Holzbock” as it’s called in German, sometimes also called castor bean tick in English, are lookalikes and difficult to differentiate. This tick prefers wildlife, pets and humans as hosts. And it’s this European tick, which is the primary carrier for the tick-borne encephalitis virus. A castor bean tick on average lives for two to three years, primarily spending its time waiting and lurking for an ideal host. Under ideal circumstances, it can survive without food for up to one year. Did you know that ticks have no eyes but instead a super-sensitive sensor called Haller’s organ on their front legs? With this organ, ticks can detect a potential host by its body humidity, odour, warmth, carbon dioxide emission, vibration and shadow.
Ticks are spider-like parasites with four pairs of legs living on blood, which they suck from their hosts, similar to mosquitoes. Compared to mosquitoes, ticks need a LOT more blood. But do ticks bite or sting like bees or mosquitoes? Research is very clear on that: they sting! But ticks don’t sting like mosquitoes, instead they use their sharply edged mandibles to slit the skin of their victims open, so they can then plunge their proboscis (which is a lot bigger than then one of a mosquito) into their host’s tissue. Then they use two different means of attaching themselves to their host: firstly they “anchor” themselves to their host with two barbs, which are on their proboscis, and secondly they produce a sort of glue five to 30 minutes after the sting with which they tightly adhere to they host. Sounds awful and terribly painful? You would think but you might have noticed that you don’t feel it when a tick stings you. This is because ticks emit an anaesthetic when stinging. Horrible but “clever” little creatures.
Ticks live outdoors, and prefer edges of forest, fields, meadows and clearings, along small streams, but are not against living in our gardens, either. You cannot find ticks above 1500 metres above sea level. They move along the ground, in high grass, bushes and undergrowth. Ticks crawl low, close to the ground and climb onto their host low, too. Only once on a host, they start to move up, along the host’s legs. They don’t drop from trees, fly or jump. Ticks love humidity and warmth, and are often particularly active after a warm shower in the summer months. When temperatures drop below 7°C, ticks become inactive but they survive winters. Their preferred temperatures are between 14 and 23°C and 80% humidity, so they are primarily active between May and October (but in mild winters they do remain active, too).
Ticks don’t have many natural enemies. Only few birds eat ticks, and ticks themselves can be infested by nematodes, killing the tick. In South Africa, small terrapins eat ticks hanging on rhinos. Some attempts have been made to naturally fight ticks, which due to recurrent mild winters over the past years have increased in numbers. The biggest hopes are “mini-wasps” which use ticks as breeding grounds for their own eggs. Wasp larvae then hatch in the tick, devour the tick within a few days and all that remains is an empty tick shell.
But until then, knowledge, being aware, and being prepared are the most important steps to prevent tick bites and disease transmission.
So, how high is the risk of a pathogen transmission in Switzerland? In Switzerland more than 30% of all ticks are carriers of Lyme Disease pathogens and it can be found all over Switzerland. Whereas in the past TBE was a risk for outdoor workers, gardeners, and forest workers, these professionals are now protected through the TBE immunisation. 80% of all patients infected nowadays are infected in their free time. TBE can be found in so called “endemic areas” or “high risk areas” and in Switzerland this includes areas of canton Zürich, Thurgau, Bern, St. Gallen, Aargau, Luzern, Solothurn, Schaffhausen, Zug, Obwalden, Nidwalden, Graubünden, Uri, Fribourg, Waadt, Wallis as well as the Principality of Liechtenstein. For up-to-date information by the “Bundesamt für Gesundheit BAG”, the Federal Office of Public Health, visit their website. Check out their link to the newly launched “Zecke” app, developed by researchers at the ZHAW (Zürcher Hochschule für Angewandte Wissenschaften) from the Department Life Sciences und Facility Management with the support of the BAG. It’s a great app, sadly available only in German, with a couple of points missing but still definitely worth downloading. I particularly like the “tick diary” where you can keep track of any tick bites and symptoms developing. You can also go directly to the map link on the Swiss Topography website. Type “tick” into the search box and choose which map you want displayed, the TBE one or the Lyme Disease one.
As mentioned, Lyme Disease is an infectious disease caused by a bacterium carried by ticks. It is the infectious disease most commonly transmitted by ticks in Europe. While ticks carrying the bacteria can be found all over Switzerland, the risk to get infected through a tick sting is only between 1,5 to 6 percent.
Research showed that during the first approx. 12 to 24 hours after a tick sting it is unlikely that a transmission of the Borrelia pathogen occurs. This is due to the fact that the bacteria is stored in the tick’s mid-intestine. After 45 hours, the transmission rate is close to 100%. People who suffer from Lyme Disease are not usually contagious, and they will not gain life-long immunity. That means that you can get infected with Lyme Disease several times in your life and you can suffer from different stages of Lyme Disease at the same time.
Symptoms of Lyme Disease vary widely making the diagnose even more difficult. One of the few, characteristic symptoms is the so called “Bull’s Eye”, Erythema migrans, or Wanderröte in German, which is typically seen 1 to 3 weeks after the tick sting. This ring-shaped rash can expand by more than 1 cm per day. However, only approx. 40% of all patients later diagnosed with Lyme Disease recall having noticed this typical skin symptom.
Other symptoms of this first, and most common, stage include fatigue, recurrent fevers and headaches. Later additional symptoms from meningitis, severe pains, joint inflammation and arthritic symptoms, to cardiovascular problems can be observed. Even neurological symptoms have been described. In children and adolescents borreliosis lymphocytoma with small, blue-reddish nodules developing around the nipples, the genital area and along the ear lobes has been described as part of stage 2 of Lyme Disease. Later stages of Lyme Disease include Lyme-Arthritis, a bacterial joint infection, and neuroborreliosis, an affected central nervous system.
Lyme Disease is diagnosed based on clinical symptoms, and in case of the definite skin sign (“bull’s eye”), blood tests are not usually required. However, if symptoms are more general, blood tests are a relevant part of the diagnostic process.
Should you see your doctor after very tick bite? No, not after very tick bite but if you develop a red or warm area on the skin where the tick stung, you should seek professional help. If you develop general flu-like symptoms, including general weakness and fatigue, even a low-grade fever, or pain and swelling in your joints, you should no longer delay a visit to the doctor.
Children often develop symptoms earlier than adults. Early antibiotic treatment of Lyme Disease in general and particularly in children has a high success rate and longterm complications are very rare.
Lyme Disease Diagnostic Tests
To diagnose Lyme Disease, two approaches are used: detection of antibodies and direct pathogen detection. Direct pathogen detection is not an option due to the slow bacterial growth of borrelia burgdorferi.
Antibody detection can be done through simple screening tests like the ELISA-Test (Enzyme-Linked Immunosorbent Assay) or more complicated confirmatory tests such as Immuno-Blot or Western-Blot. Confirmatory tests guarantee that the simple screening tests did not bring false-positive results. This means, to confirm an acute Lyme Disease, your doctor needs to run a confirmatory test after a positive screening test. A stand alone screening test is not considered sufficient to diagnose Lyme disease; the confirmatory Western blot also has to be positive.
Antibodies can also be searched for in liquor obtained through lumbar puncture. This is usually done if neuroborreliosis is suspected (meningitis, severe headache).
In the early stages of Lyme Disease, antibody screening tests can be negative. The only way to prove an infection is present would be if the pathogen were detected. As a direct microscopic detection of borrelia burgdorferi is not possible, a PCR test (Polymerase-Chain Reaction test) is used to detect bacterial DNA from synovial fluid, fluid obtained from an infected joint.
Remember, once a blood test is positive for Lyme Disease, it will remain positive for a long time even with successful treatment. Repeat blood tests, including after treatment, do not determine further care. And what do positive test results actually mean?
- If a blood test for IgM and IgG is positive, and the confirmatory Western blot is also positive, it is likely that the person has Lyme Disease.
- On the other hand, if the blood test for IgM is positive but the one for IgG and the Western blot are negative, it is likely that the result is false-positive.
- If the blood test for IgM and IgG is negative, a confirmatory Western blot is not required (and should also be negative), no infection is present and the symptoms are most likely due be due to another cause (or antibody levels are still too low to be detected).
- If the PCR test result is positive, it’s a sign for a recent infection with the Lyme Disease bacterium. If the PCR test result is negative, no infection is present (or the level of the DNA is still too low to be detected).
Tick Borne Encephalitis
The German name for tick-borne encephalitis, Frühsommer-Meningoenzephalitis (generally abbreviated to FSME), is based on the fact that TBE was first described in early summer months. TBE is caused by the Tick-borne encephalitis virus (TBEV) and treating the cause of this infection is thus not possible. Once TBE has broken out, it is only possible to alleviate the symptoms. It is therefore particularly important to prevent this infection.
Tick-born encephalitis typically has a two-phase course: a first phase with fever, headache and joint aches, like a flu. In some patients, the virus will affect the central nervous system, the mildest form being a meningitis (an inflammation of the membranes lining the brain) with high fever, severe headache and neck stiffness. The more severe form is the encephalitis, an inflammation of the brain itself. This can lead to impairment of consciousness, disturbances in speaking and swallowing, mental changes and paralysis. 10 to 20% of those with severe symptoms will suffer from long-term complications. The older a person is, the higher the risk of suffering from encephalitis and even an inflammation within the spinal cord.
According to the Robert-Koch-Institut, the German institute for disease awareness and prevention, the method of choice to diagnose a TBE infection, is the simultaneous detection of IgM and IgG antibodies specific to the TBE-virus, which can be found in the blood and the liquor. Alternatively, the ELISA-test can be used: a significant increase in antibody concentration between two blood samples taken at a 2-to-4 week interval confirms the diagnosis of TBE.
Switzerland is not the only country affected by TBE. Cases have been described in many European and Asian countries, including Austria, Germany, Scandinavian countries (Sweden, Norway, Denmark), and Eastern European countries like Albania, the Baltic states, Croatia, Czech Republic, Hungary, Poland, Russia, Slovak Republic, Slovenia, Ukraine.
Since treatment of Tick-Borne Encephalitis can only be symptomatic, immunisation plays an important role in the prevention against this illness. As mentioned earlier, the recommendation who should be immunised is much more general these days: anyone, who spends considerable time outdoors in a high risk area, should be immunised. To be fully protected, three shots are needed. The immunisation process can be started at any time during the year: ticks are not only active in the spring and summer but can be around a lot earlier and long into the autumn months (and even into mild winter months). The initial immunisation includes two shots at a one-to-three-month interval. Approximately two weeks after the second shot the protection is about 98% (but lasts only for one year). Don’t forget that booster shots are needed, too.
Let‘s be straight from the beginning, there is NO such thing as hundred-percent protection against ticks. But you can do lots to avoid tick bites.
- avoid high grass and undergrowth
- wear long-sleeved shirts and long pants
- tuck long pants into socks, so ticks cannot get underneath pants and crawl up your legs on your skin (remember: ticks are on the ground and crawl up)
- wear light-coloured clothing, so you can spot ticks easier and remove them before they bite
- use insect-repellent sprays (but remember, they don’t offer 100% security)
- after a day outdoors, do a full “body check” on yourself and your children
Repellents are an important part of protection against ticks and there are several approaches using chemical or natural products, the most commonly known ones being DEET and permethrin.
DEET repels ticks but doesn’t kill them, permethrin on the other hand kills ticks on contact. Permethrin is the synthetic form of the naturally occurring insecticide pyrethrum, which comes from Chrysanthemums. Permethrin, when used as an insect repellent, is used on clothing only, not on skin. You can hence buy clothing that is treated with permethrin providing long-lasting protection. Chemical compounds similar to pyrethrum are called pyrethroids, which are also used to impregnate mosquito nets.
A test by the Swiss consumer protection publication K-Tipp showed that the vast majority of tick repellents on the market are ineffective. It also showed that effective protection does not have to be expensive: the best protection was through test winner No Skito. No Skito is a plant based biocide and protects up to 6 hours. It also contains aloe vera and is particularly skin-friendly. It can also be used for toddlers from one year. Whenever you use a biocide, which by definition is “a chemical, such as a pesticide, capable of killing living organisms”, read the labelling and product information before using it.
How and why do these natural products work? Well, some don’t but those that are effective use the Haller’s organ to trick ticks and it seems that the essential oils of eucalyptus, geranium, black cumin and in particular coconut are the most effective ones, possibly even used in combination. By the way, the black cumin oil repellent was a coincidental find by a high school student as part of a science competition just last year. Whether an oil, or a combination of oils, is effective as a repellent, will vary from person to person, as we differ from one another in our metabolism and our skin and airway emissions. This explains why one oil can be described as highly effective by one person, but as completely ineffective by another. Using an oil, or oils, as a repellent against ticks is thus a trial and error experience. Keep in mind that oils may cause allergies or skin reactions, especially in combination with sun exposure, so carefully test an oil before applying it on larger skin areas. It seems that especially in regard to skin tolerability and its repellent effect due to its high lauric acid content, coconut oil is especially worth a try. All oils are only effective for approx. 3 to 4 hours, so repeated use (i.e. rubbing the oil into the skin) might be needed.
The other products that tested with good results were Anti-Brumm Naturel, Anti Insect Zecken by Migros and Anti Brumm Zecken Stopp. New on the Swiss market and very convenient for travelling and when on a hike, are the ZeckenStop wet wipes (Feuchttücher). They contain Icaridin, like Anti-Brumm Zecken Stopp, and the Migros Anti Insect Zecken spray.
Full Body Check
Your best bet is to remove ticks from your body after a day outdoors. Perform what I call a full body check, meaning search your entire body, especially around thin and warm skin areas: in armpits, in the back of the knees, along the neck and the airline on the head, on your ears and around the eyes. And don’t forget the crotch.
Found a tick on you?
Firstly, not every tick is infected and carries pathogens. Secondly, the pathogens for Lyme Disease are not transmitted right away. In a tick, these pathogens are stored in its mid-intestine. Only when the tick has started to suck blood, the bacteria are signalled to spread out and move to the tick’s salivary glands. From there they can move with the tick’s saliva into the sting wound. This process usually takes 24 to 30 hours.
The pathogens for TBE, or FSME, however, are stored in the salivary glands of the tick and can be transmitted relatively quickly after the tick sting. It is therefore good that there is an immunisation against TBE.
Tips for successful tick removal
- When you find an attached tick, it should be removed soon. You don’t need to interrupt a hike or walk in the forest, but as the risk of pathogen transmission increases with time, it is best to carry a tool to remove the tick along on a hike (remember: it takes approx. 24 to 30 hours for the Lyme Disease bacterium to be transmitted but the pathogen for TBE is transmitted soon after the tick sting).
- Do not use cleaning petrol (benzine), spirit, alcohol, nail varnish remover or oil. Do not use a lighter or matches to kill a tick still attached to the skin. All of these substances may increase the risk of pathogen transmission.
- If the tick sits in a hard to reach location, you should ask a second person to help. Worst case, you might have to seek medical help.
- Pointed tweezers or tick safe cards are the safest tool to remove a tick. My preferred tool by far are definitely tick safe cards because they are much easier to use, safe and a perfect size to be carried in a wallet at all times (don’t go on a hike or outdoors without one).
- When using a tick card or pointed tweezers, aim as close to the skin as possible and once you’ve grabbed the tick, or trapped it in the notch of the card, pull it straight up in a smooth movement against the tick’s resistance. Do not twist or turn the tick or remove it in a jerky movement as this increases the risk of leaving the head in the skin.
- Don’t stop looking for ticks just because you found one: there could be more.
- Once you removed the tick, disinfect the sting area using an antiseptic ointment or alcohol. My preferred antiseptic is “Betadine”, an ointment you can get over the counter at every pharmacy in Switzerland. Use a drop of it on the tick sting area several times for the first two days.
- Don’t give up if your attempts don’t seem successful, keep trying.
- If a red area around the tick sting doesn’t disappear or even increases, seek medical professional help. The same applies if the area starts to swell, becomes painful, warms up or throbs.
Once you’ve removed the tick from your clothing and your body, what do you do with it? Not much formal research has gone into ticks’ ability of surviving in the water, but the Rhode Island University Tick Resource Center observed that while ticks are not able to swim, they can “be submerged in water for 2-3 days and seem to survive just fine”. This is important as many people think that ticks will be killed when taking a bath or a shower after a day out and putting clothes in the warm wash cycle of your washing machine. Well, not so much: ticks are tough creatures and survive such “treatments. Even flushing them down the toilet does not kill them. They also survive freezing cold: tests showed that ticks survived up to 24 hours in a freezer!
So, what DOES kill ticks? Don’t just step on the tick you just removed from your body: unless it’s sucked full of blood is so small, it might survive. Place the tick between a folded piece of paper or aluminium foil, and use something really hard, like a glass, to crush the tick. This method seems to work for adult ticks and for nymph. Make sure you don’t touch the tick with your fingers and discard it in the paper or foil. You can also use 40% alcohol, bleach or a disinfectant to kill the tick.
Testing Ticks for Borrelia and TBE
If you want to know whether the tick you removed carried the Lyme Disease pathogen, you can send it to a lab to have it tested. This service is also available in Switzerland. You buy the tick test sold by Anti-Brumm® in pharmacies (and online) for approx. CHF 85. Once you paid for the test package, you can send in the tick along with your name, address, and telephone number. Within only 2 to 3 days, you can access the test result on the “Zeckentest” website. The result is 99% safe. Considering that early signs of Lyme Disease, which are very general and flu like, are very hard to pinpoint, the test can be an early indication to start an antibiotic treatment. Yet just because the tick is positive does not mean that the pathogen was transmitted.
There are two labs offering tick tests: one in Switzerland, the Anti-Brumm® Tick Test, for which you buy the test in pharmacies (approx. CHF 85 per test). This test only tests ticks for borrelia, the bacterium causing Lyme Disease. Alternatively, Labor Enders in Stuttgart also performs test on ticks. They assess ticks for Lyme Disease and also for Tick Borne Encephalitis. You can also download the tick order form directly here. Simply fill out the form from the website, tape the tick on to the paar using a strip of transparent tape (do not tape the tick between two strips of tape). Alternatively, you can place the tick in the cut-off corner of a freezer bag. Make sure you use a firm envelope for mailing the order form and the tick. On the form you need to check what you want the tick being tested for, Borrelia (Lyme Disease) or FSME-Virus (TBE). Costs for the test are € 25.-) and € 45.- respectively.
Last but not least, for the parents among the readers, how do you protect your children?
From spring onwards, children love to spend their days outside, roaming through the forest, hiding behind bushes and shrubs, or building a fort in the garden. Which means nothing but that the mentioned protective measures apply in particular to children.
In regard to repellents, “Anti-Brumm® Naturel”, which uses citriodiol, an extract of Eucalyptus citriodora, can be used on toddlers from one year old, as long as hands and mouth area are left out. When using the “Naturel” spray together with sunscreen, a minimum of 20 minutes should pass after applying the sunscreen before using the insect repellent. Don’t forget to spray clothing, too.
As mentioned earlier, plant based biocide No Skito and Anti Insect Zecken by Migros can also both be used on toddlers from one year.
Anti-Brumm® Zecken Stopp uses a combination of citriodiol and icaridin. Icaridin, also called Picaridin or Saltidin, was found to be as effective as DEET protecting against ticks when used in a 20% concentration. No data is available for use on young children and should therefore not be applied on children younger than 2 years. Icaridin smells much more agreeable compared to DEET and usually does not irritate or sensitise the skin. The ZeckenStop wet wipes can also be used on children on children from age 2 years.
The last repellent to have tested effective, Anti-Brumm® Forte, which contains Diethyltoluamid (DEET), should only be used sparingly and if really required. Children are likely to absorb more DEET than adults as it is absorbed by the skin and excreted by the kidneys (and children have a larger skin to body weight ratio than adults). Since 2013 Anti-Brumm® Forte is only recommend for children older than 12 years.
Putting all of this into a short paragraph, you can say that ticks can be a pain but there is a lot you can do to protect yourself against the pathogens they potentially carry: that of Lyme Disease and the one of Tick-Born Encephalitis. Know your ticks and get tick smart to be on the safe side. Remember, even if you are immunised against TBE, there is no immunisation against Lyme Disease, so checking your body for ticks is an essential preventive measure to protect yourself against Lyme Disease.
Whether you use a tick repellent and if so which one you choose, in the end, is your decision. And while clothing treated with a chemical or just putting a chemical on our body to repel ticks might sound off-putting, we should keep in mind that a large proportion of the clothing we wear is treated with some sort of chemical finishing anyway, usually without any benefit for us. At least the ones mentioned earlier do protect us from these nasty little creatures.
I apologise for this post having become a lot longer and more detailed than I originally intended, and there is so much more to learn and know. I did not talk about the tick immunisation, in German correctly called the FSME-immunisation. The immunisation only protects against TBE, not against Lyme Disease and I will write a post about the immunisation some time in the future. In the meantime, if you have any comments or questions, please send me an email.
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