Frequently asked questions about ticks

What are ticks?

Ticks are mainly found in tall grass and shrubs. They do not fall from trees. Ticks are small brown-black animals that resemble small spiders (3-4 mm in size). Ticks require blood to reproduce. They obtain blood by attaching to the skin of humans and animals and engorging themselves with blood. A tick requires various blood meals to develop into an adult tick. As soon as a tick larva hatches from an egg, it searches for a host - a small mammal - for the first blood meal. If the host is infected with the bacterium Borrelia burgdorferi, the larva can also become infected. The larva grows following the first blood meal and becomes a nymph. The nymph also goes out hunting for blood; from animals and sometimes people. If the nymph is infected with the bacteria it may now infect other animals or people. The nymph becomes an adult tick after the second blood meal. The adult tick now heads out in search of blood. The bacteria can also be transmitted at this stage.
The time of year that ticks are active is very dependant on the weather. They are certainly present between April and September.

How do you recognise a tick?

A tick is very small and resembles a small spider of only 1 to 3 millimetres. When sucking blood, ticks swell to look like a little ball. A fully engorged tick can even have a diameter of 1 centimetre.

What do ticks do?

Ticks are parasites: they live from the blood of people or animals. Their bite is usually painless. They can remain in the skin and engorge themselves on blood unnoticed for hours or even days. Usually tick bites are harmless. However, it is important to remove the tick as soon as possible and in the right way. Ticks can be infected with the bacteria Borrelia burgdorferi, which can cause Lyme disease. A bite from an infected tick can lead to the bacteria entering your body. Immature ticks, called nymphs, are probably the most important transmitters of infections in humans. They are easily overlooked because they are so small; no larger than the head of a needle.

Where are ticks found?

Ticks can be found throughout the Netherlands. They live in high grass and bushes in forests, dunes, islands, heathland areas, gardens and parks. From research conducted by the RIVM it appears that they are more prevalent in the Achterhoek, Drenthe, Veluwe, the Utrechtse Heuvelrug, South Friesland and the dune areas.

When are ticks active?

Ticks can be found throughout the year. They become active as soon as the temperature rises above 8-10 degrees Celsius; sometimes even when it is warmer than 5 degrees Celsius. Most people are bitten in the April to September period.

How often do tick bites occur?

In 2005 approximately 73,000 people visited their doctor because of a tick bite. However, the actual number of tick bites is higher. Previous estimations have indicated that more than a million Dutch people receive a tick bite every year.

How many ticks in the Netherlands are infected?

That really depends on the area and the overgrowth. Not a lot of areas in the Netherlands have been examined. From research conducted by the RIVM in the period 2000 to 2004, it appears that the percentage of ticks infected with the Borrelia bacterium fluctuates between 0.8 and 11.5%.

How do I prevent being bitten by a tick?

Avoiding contact with shrubs and tall grass reduces the chance of a tick bite. Stick to paths and cover your body as much as possible. If possible, wear closed shoes, long sleeves and trousers with the legs tucked into your socks. This does not guarantee that you will not receive a tick bite, but it does reduce the chance. The most important advice is to check your skin and clothing carefully after an excursion into nature. In particular, look closely at the areas where the skin is thin, warm and moist.

Are children more vulnerable?

Children play outside and are more likely to leave paths. As a result, they are more at risk of receiving a tick bite. Furthermore, ticks usually live at a maximum height of around one and a half metres. It is therefore easy for them to climb onto the head of a child. A cap decreases the risk, similar to wearing a shirt with long sleeves or trousers with the legs tucked into the socks. It is important to regularly check children for ticks when they have been playing in nature.

How do ticks make you ill?

Ticks can only make someone ill if they are infected with bacteria that can cause disease, AND if they have been attached to the skin for a sufficient period of time. In the Netherlands ticks mainly carry the Borrelia bacterium, which can cause Lyme disease. If a tick is infected, the bacteria are located in the gut. The bacteria can end up in the human body together with the contents of the gut via the tick's saliva. It takes a bit of time before the bacteria reach the salivary glands. If the tick is removed within 24 hours, the chance that bacteria are transmitted is virtually zero. If the bacterium does end up in your body, you may contract Lyme disease.

What is Lyme disease?

Lyme disease is an infectious disease that can be caused by the bacterium Borrelia burgdorferi. The bacteria can enter the human body via a tick bite. After 3 days to 3 months, with an average of 16 days, a red ring may appear on the skin in the area of the tick bite.
This does not always happen: you can also contract Lyme disease without the red ring appearing. Another symptom is a flu-like feeling accompanied by complaints such as fever, headache and joint pain. In a later stage of the disease there is a chance of paralysis of the facial muscles, strong pain in an arm or leg, double vision, loss of strength in the legs, painful or swollen joints,
a tendency to faint and heart complaints. Lyme disease can be treated well with antibiotics. The earlier it is discovered, the better and faster it can be treated.

How prevalent is Lyme disease?

In 2005 approximately 17,000 people visited their doctor with the first symptoms of Lyme disease.

Who can contract the disease and who is most at risk?

Everyone can become infected with Borrelia bacteria and contract Lyme disease. People most at risk are those that take part in recreation involving nature, such as walkers and campers. People who spend a lot of time in nature as part of their job, such as forest workers, hunters and field biologists, also run a greater risk.

How do I prevent Lyme disease?

It is sensible to carefully check your body and that of your children for ticks following every excursion in nature. In particular, closely examine warm areas such as armpits, groins, anal cleft, and the back of the knees. Ticks also nest - especially with children - on the head, behind the hairline and ears.
In particular, examine warm and moist areas of the body. Spend extra effort with children examining their head.

What should I do if I have been bitten by a tick?

• Remove the tick within 24 hours! This is of most importance.
• Do not drink alcohol, use iodine, oil or other substances until the tick has been removed. This can affect the removal.
• Grab the tick as closely to the skin as possible, preferably with pointy tweezers or special tick tweezers. Pull the tick out slowly and be careful to avoid crushing the tick. If a piece of the tick's mouth parts remains in the skin, it is not harmful. It will come out by itself like a splinter.
• Disinfect the area of the bite with 70% alcohol or iodine.
• Note the date that you were bitten in your agenda.
• Keep an eye on the area of the tick bite for 3 months following the bite. Look for the development of a skin rash in the form of a red ring and flu symptoms such as fever, headache and joint pain.
• See your doctor if the red ring on the skin grows bigger than 5 centimetres, or if you have one of the above mentioned symptoms.
If so, inform your doctor of the date you were bitten.

Do I need to use special tweezers to remove a tick?

No, that is not necessary. Pointy tweezers do make it easier to grab the head of the tick and reduce the chance that you accidentally crush the tick.

What is the chance of being infected?

We do not know the exact chance of becoming infected after a tick bite. On the basis of available research results, the average chance of becoming infected in the Netherlands is estimated to be less than 5%. If the tick is removed within 24 hours after being bitten and removed in the correct manner, the chance of being infected is almost zero. People cannot infect each other and you can also not get infected while removing a tick from an animal. However, every tick bite renews the chance of becoming infected. There is currently no good vaccination available to prevent the disease.

Does it matter whether the tick has sucked a lot or only a little blood?

A tick that has sucked a lot of blood has been attached for longer than one that has not sucked any blood. The longer an infected tick remains attached, the greater the chance that the Borrelia bacteria are transmitted. After 72 hours the chance that an infected tick has transmitted the disease due to the bite is estimated to be almost 100%.

Is it possible to have Lyme disease without having seen a red ring?

Yes. A quarter of people who test positive to Lyme disease using a blood test, have not seen a red ring.

When should I see my doctor?

You should only see your doctor if you have a red ring on your skin and that ring has grown to over 5 centimetres within several days. You should also visit your doctor if a tick bite results in paralysis of your facial muscles, strong pain in an arm or leg, double vision, loss of strength in your legs, painful or swollen joints or a tendency to faint. If you have a red ring, your doctor will prescribe antibiotics. You will be referred to a specialist if your symptoms are serious.

What does a small red mark on my skin mean?

A red mark often appears on the skin after a tick bite. This is normal. If this small patch does not grow to larger than 5 centimetres and disappears again within several days, the chance is virtually zero that the mark is a symptom of Lyme disease.

When are blood tests necessary?

Your doctor will perform blood tests if there are clear indications that Lyme disease is involved. Symptoms such as tiredness, memory and concentration disorders alone are not reason enough
to have blood tests performed; neither are joint complaints in the absence of arthritis symptoms.

Can I undergo blood tests immediately after a tick bite?

There is no point. If someone is infected by a tick bite, it can only be found in the blood 6 to 8 weeks later. If the blood is examined earlier, it may lead to a wrong result.

What should I do if I receive a tick bite outside the Netherlands?

Outside the Netherlands, ticks may also carry other diseases than Lyme disease. If you are outside the Netherlands you should also remove the tick as soon as possible - within 24 hours - and in the right manner. Make a note of the following information:
• the date of the tick bite;
• the site of the tick bite on the body;
• the country and area where you received the tick bite.
Report these details to your doctor if you start to suffer from health problems in the 3 months following the bite.

How is Lyme disease treated?

The disease can be treated well with antibiotics.

How is Lyme disease treated if it is discovered at a later stage?

Antibiotics are also used at a later stage.

Is there a vaccine against Lyme disease?

A good vaccine is not currently available.

Can you become immune to Lyme disease?

No, each new tick bite renews the chance of infection.

Can Lyme disease become chronic?

If the disease is not discovered in time, people can develop chronic skin disorders and serious joint complaints. The earlier you discover the disease, the better and faster the disease can be treated with antibiotics.

Does everyone infected with the Borrelia bacterium develop Lyme disease?

No. Most people are able to fight the infection with their own immune system.