What is Lyme disease?
Lyme disease (Lyme borreliosis) is an infection caused by bacteria known as Borrelia (B. burgdorferi, B.garinii and B. afzelii).
How is Lyme disease spread?
The Borrelia bacteria are carried by infected ticks that feed on blood when they bite a person. The tick injects the bacteria into the person’s blood while feeding and this leads to infection.
Will a tick bite always result in a person getting Lyme Disease?
No, not always, even if bitten by an infected tick. We know this because studies that tested large groups of people (such as blood donors) from areas with high levels of ticks, showed that around 1 in 5 people have a blood test result showing they were infected with the Lyme bacterium at some stage of their life, without remembering a tick bite or having symptoms of Lyme.
In general, the longer the tick has been attached to the skin, the greater the chance is of being infected. All the evidence suggests that ticks need to be attached and feeding for quite some time (as long as 24 hours) before there is a risk of becoming infected. All the evidence suggests that if a tick is removed as soon as it bites, the risk of infection is very low.
What are the symptoms of Lyme disease?
Some people with Borrelia infection will have no symptoms. For those who have symptoms (Lyme disease) the illness is described as having three different stages.
1. Early localised disease:
In about three quarters of cases the patient develops a characteristic “bulls-eye” red rash (erythema migrans) spreading outwards from the site of a tick bite. The patient may also have vague 'flu-like' symptoms. The rash may be very faint and not easily noticed, especially if the bite was not in an obvious area. The rash and other symptoms can resolve even without antibiotics. However, treatment of Lyme disease with antibiotics at this stage is still advised to reduce the chance that the disease may progress.
2. Early disseminated disease:
During this stage the bacteria may spread around the body in the blood causing any of the following symptoms:
- severe flu-like illness
- multiple rashes like erythema migrans (usually smaller)
- facial nerve weakness, facial droop or other neurological problems in the head and neck
- meningitis (swelling of the layers around the brain)
- arthritis (swelling and pain in joints)
- heart problems
Treatment of Lyme disease with antibiotics at this stage is also advised.
3. Chronic disseminated disease:
Progress to this stage is uncommon but may occur in patients who did not receive enough treatment at an earlier stage. This stage most commonly involves joints, particularly the knee. A skin condition known as acrodermatitis chronica atrophicans (ACA) may occur at this stage. ACA is most evident on the hands and feet. It begins with bluish red discoloration of the skin and skin swelling. ACA may last several months or years. As ACA progresses the skin may become thin, translucent and begins to wrinkle. Patients with chronic disseminated Lyme disease may not remember a tick bite as the bite may have occurred years previously at this late stage of infection.
How is Lyme disease treated?
Common antibiotics (such as doxycycline or amoxicillin) are effective at clearing the infection and early symptoms and in helping to prevent the development of complications. If untreated, the disease will progress to a longer-term form in about half of patients. Antibiotics are generally given for up to three weeks. If complications develop, intravenous antibiotics may need to be used to treat the infection. The bacteria can survive for long periods in the body even if no symptoms develop. If untreated, the bacteria can cause chronic irritation in in a number of the body’s organs. That is why early diagnosis and treatment with antibiotics is important.
How is Lyme disease diagnosed?
Lyme disease is diagnosed by taking a medical history and physical examination of the person. Diagnosis can be more difficult if the typical Lyme disease rash was not seen. The infection is then confirmed by blood tests. The tests look for antibodies to B. burgdorferi which are produced by an infected person's body in response to the infection. Antibodies will take several weeks to develop so may not be present in the early stages of the infection but will usually be present in the later stages of the infection. Detailed information on laboratory testing of Lyme disease is available on the HPSC website.
How common is Lyme disease in Ireland?
Figures are not available for the number of cases of Lyme disease in Ireland as only a more severe form of the disease known as neuroborreliosis is monitored as a notifiable disease. However, it is estimated that around 200 people have a positive blood test for Lyme disease each year.
Who is at risk of Lyme disease in Ireland?
Lyme disease can affect anyone but is commonest among hill-walkers, hikers, campers and others whose leisure activities or work takes place in heathland, light woodland and other grassy areas or brings them in contact with certain animals e.g. deer and sheep. Summer and autumn is the period when most cases occur.
Which sorts of environments am I most likely to find ticks?
Ticks are active from spring to autumn and can be found in both urban and rural environment. Ticks are most likely to be found in the following areas:
- Shady and humid woodland clearings with grass
- Open grassland, parkland, fields and bushes
- Walking paths, especially those bordered by long grasses
- Wooded and forested areas
- Vegetation close to lakes and seaside beaches
How do I remove an attached tick?
- If you find an attached tick, remove it by gently gripping it as close to the skin as possible using a pair of fine tipped tweezers or tick removal tool
- Pull steadily away from the skin without twisting or crushing the tick
- Wash your skin with warm water and soap afterwards, and apply an antiseptic cream to the skin around the bite
- Do not use a lit cigarette end, a match head or substances such as alcohol or petroleum jelly to force the tick out
How can I protect myself from Lyme disease?
Before going out in areas where ticks are found:
- Cover exposed skin by wearing long trousers tucked into socks/boots and long sleeves tops
- Wear closed toe shoes or boots rather than sandals
- Use repellent that contains at least 20% DEET or picaridin or IR3535 on exposed skin taking care to follow product instructions and avoiding hands, eyes, and mouth. (DEET is safe to use during pregnancy and while breastfeeding but only in concentrations less than 50%. DEET is only safe for babies aged 2 months and older.)
- If using sunscreen, tick repellent should be applied after sunscreen.
- Use repellent that contain 0.5% permethrin on clothing, back packs and tents
- Inspect your skin and clothes every 3-4 hours while in areas where ticks are found
After returning from area where ticks are found: find & remove ticks from your body
- Bathe or shower as soon as possible after coming indoors (preferably within 2 hours) to wash off and help find ticks that are crawling on you
- Conduct a full-body tick check using a hand-held or full-length mirror to view all parts of your body upon return from tick-infested areas
- Parents should check their children for ticks under the arms, in and around the ears, inside the belly button, behind the knees, between the legs, around the waist, and especially in their hair
After returning from area where ticks are found: find and remove ticks from your pets/ clothing
- Examine gear/clothing and pets. Ticks can ride into the home on clothing and pets, then attach to a person later, so carefully examine pets, clothing and back packs.
- Tumble dry clothes in a dryer on high heat for 10 minutes or until the clothing is dry to kill ticks on dry clothing after you come indoors.
- If the clothes require washing first, hot water is recommended. Cold and medium temperature water will not kill ticks effectively. If the clothes cannot be washed in hot water, tumble dry on low heat for 90 minutes or high heat for 60 minutes. The clothes should be warm and completely dry.
How can I improve awareness of Lyme disease in my community or club?
HPSC has produced a Lyme and tick leaflet on Protecting Yourself Against Tick Bites and Lyme Disease to help raise awareness of Lyme disease and promote prevention methods. An A3 poster is also available on the HPSC website. If you own or manage land on which people walk, you can download the poster and place it in a prominent position at the entrance and exit areas of the land.
Should I take antibiotics after being bitten by a tick to prevent Lyme disease?
It is not recommended to take antibiotics to prevent Lyme disease following a tick bite. Following a tick bite, there is likely to be an area of redness whic look like nettle or bee stings. These are allergic reactions to the tick's saliva and do not indicate infection. If you develop symptoms, such as a rash, you should visit your GP and tell them about the tick bite.
Is there a vaccine against Lyme disease?
There are Lyme disease vaccines available for dogs. Currently, however there is no vaccine available against human Lyme disease in Ireland. A US human vaccine was withdrawn in 2002. There have been concerns that certain Lyme vaccines could lead to arthritis. Active research into vaccine development is taking place in Europe and the US, and some candidate vaccines are beginning to show promise.
If I am worried about Lyme disease who can I talk to?
Lyme disease is being increasingly recognised as causing illness and hardship, if the diagnosis is missed. Over the last number of years, there has been a marked increase in awareness of the condition among GPs and hospital doctors in Ireland. Each of the HSE’s Hospital Groups have a number of Infectious Disease Consultants who are expert in the diagnosis and management of Lyme disease. If you have been bitten by a tick or have other reasons to strongly suspect you may have Lyme disease, you should visit your GP for advice.