Thursday, February 17, 2005
The risk from a tiny terror
Special Article - Borreliosis / Lyme disease
Please read this important article. It affects everyone working with
animals (and others). The author prefers to remain anonymous. Contact
may be made with her at the email at the end of the article.
The risk from a tiny terror
The Game Conservancy Trust this year expressed concern at the rise in
the population of ticks, which are decimating the game bird
population. But it doesn't stop there. Studies have shown vast
numbers of ticks on kittiwakes, migratory songbirds and mammals of
all sizes. Scientists from the Game Conservancy Trust have radio-
tracked waders to try to see the extent of the problem and have found
wader chicks at only three weeks old with heavy tick infestations.
The milder winters seem to be supporting the tick population and it
is increasing each year. In 1985 the percentage of grouse chicks
infested was 4%. By 2003 that number had risen to 92%
With the explosion of the tick population comes a higher risk of tick-
borne diseases. For all those involved in animal husbandry this is an
important topic that is very relevant to you. We and the animals we
care for are at daily risk of suffering a devastating combination of
infections that can lead to euthanasia of our animals and the
devastation of our own lives.
Borreliosis / Lyme disease
Borrelia bacteria are spirochaetes. These are long thin spiral shaped
bacteria and are closely related to those causing syphilis. Borrelia
are pleomorphic meaning that they can exist in several different
forms including a dormant cyst, a motile spirochete and intracellular
cell wall deficient form. These spirochaetes are able to change form
when their environment is not optimum such as when antibiotics are
introduced. The pleomorphic nature of this bacterium makes it very
difficult to eradicate. Borrelia can invade and reside in every
tissue type and fluid in the body. Many symptoms are brought on by
Borrelia as it causes the immune system to produce cytokines
(chemical messengers that help to regulate the immune response) and
it produces many bio-toxins, mainly neurotoxins, which are attracted
to many areas of the body such as the central nervous system,
peripheral nerves, muscles, joints, lungs etc.
There are many hundreds of strains and sub-types of Borrelia but most
of these are unstudied. The four most commonly identified in the UK
and Europe are Borrelia burgdorferi, Borrelia garinii, Borrelia
afzelii and Borrelia valaisiana. As all these species are endemic to
the UK it is possible to be infected with multiple strains. It is
because of the multitude of strains that many doctors refer to an
infection as Borreliosis rather than Lyme disease which is caused
strictly by Borrelia burgdorferi.
Borreliosis / Lyme disease clinical symptoms are most commonly seen
in dogs, horses and humans. Whilst the rate of Equine Lyme disease is
considered to be on the increase. Borrelia have also been isolated
from fleas and mosquitoes and studies suggest that the disease can be
contracted from biting insects other than ticks. Borrelia can be
passed from mother to unborn child and it has also been found in
saliva, breast milk, semen, tears, urine and unpasteurized cow's
milk. This demonstrates the remarkable abilities of this bacteria,
the possibility of sexual transmission and why it is so hard to
Being bitten by a tick does not stop at the transmission of Borrelia.
One bite can inject a variety of different bacteria and protozoa.
Species of Babesia, Bartonella, Ehrlichia, Rickettsia, are commonly
identified alongside Borrelia in blood samples. Louping ill and tick
fever which commonly affect sheep, also affects birds. Tick fever
causes Hydrocephalus which can also prove fatal in humans.
In one UK study, blood samples from a flock of sheep were tested by
PCR (Polymerase Chain Reaction) finding that 100% of the flock were
carrying Louping ill and 80% tick fever. The presence of these
diseases in flocks across the UK spreads the infections far and wide
within the surrounding wildlife as ticks feed from multiple hosts
throughout their life cycle. When applying the same theory to
ungulates/ruminants and other mammals in the field it becomes a
roulette game just to practice animal husbandry.
Ticks are designed to bite and feed un-noticed. The saliva contains a
natural anaesthetic which means the tick can feed without causing
irritation. During the bite the tick injects numbing saliva but as it
floods into the blood stream, so can a concoction of co-infections.
Once engorged, if disturbed or damaged, the tick will regurgitate to
get rid of its cumbersome load; pumping further pathogens into the
host. Smothering or burning an attached tick will almost certainly
In the UK the most common species of tick to transmit disease to
humans are from the family Ixodidae. The sheep tick (Ixodes ricinus)
is also known as the castor bean tick. It is also known to infest
deer and in larval and nymph stage, small mammals and birds. Ticks
have three distinct life stages. Larvae which emerge from the egg
have six legs. After obtaining a blood meal from a vertebrate host,
they moult to the nymph stage and acquire eight legs. Nymphs feed and
moult to the next and final stage - the adult, which also has eight
legs. After feeding once more, the adult female ticks lay one batch
of thousands of eggs and then dies. Only one blood meal is taken
during each of the three life stages. The time to completion of the
entire life cycle may vary from less than a year in tropical regions
to over three years in cold climates, where certain stages may enter
diapause until hosts are again available. Many ticks can go for
several months without feeding. Questing ticks searching for a
suitable host are known to climb up and on all manner of vegetation,
then wait in ambush with the front legs extended, especially in
response to a host passing by. Certain biochemicals such as carbon
dioxide as well as heat and movement serve as stimuli. The tick then
latches onto the unsuspecting host, having brushed against or
disturbed the vegetation. Once on the host they will search for a
safe area to feed where blood is close to the surface.
It is difficult to differentiate the symptoms of many of the tick-
borne diseases as they often overlap. Multiple infections also make
it difficult to identify what is causing individual symptoms. Both
animals and humans can display similar symptoms but of course only
observation and grooming of the animal species will indicate the
possibility of early infection.
In humans one symptom that is considered a classical symptom of a
Borrelia / Lyme disease infection is a bullseye rash (Erythema
Migrans) which can occur after the initial bite, however studies have
shown that as few as 40% of serology positive sufferers ever recall
the appearance of any rash. Many symptoms are similar to those
normally associated with chronic fatigue type syndromes including
painful joints and muscles, Carpal Tunnel Syndrome, brain fog, memory
problems, headaches, flu-like fevers, neurological symptoms, stiff
neck, numbness, tingling, extreme fatigue, fibromyalgia, sleep
problems, hypotension, noise or light sensitivity and many more. In
chronic phase Borreliosis / Lyme can mimic other diseases such as
Multiple Sclerosis, Lupus and Motor Neurone disease. Severe infection
can lead to Transverse Myelitis during which the swelling of the
spinal cord and cerebral tissue can lead to permanent paralysis and
other neurological damage. Some symptoms of many of the tick-borne
diseases can occur within a few days or weeks of a tick bite, but for
some it is much longer and can extend to years. The symptoms can be
cyclical. Women around the time of menstruation can experience
exacerbation of symptoms. Each day can bring a variety of symptom
presentation making it unpredictable. Some people get the illness
more severely than others. It is known to affect the elderly more
severely and pre-existing medical conditions can influence the
outcome of any infection. If untreated some people may go on to
develop long term or life-long debilitating illness. Some cases prove
fatal. Some people can go into remission after a period of time, only
for the disease to recur later.
In the UK all medical practitioners rely on a two tier testing
system. The first is an ELISA antibody test. The second stage is a
Western Blot. Both these tests rely on the presence of antibodies,
which is a problem as Borrelia has the ability to evade detection by
the immune system. Borrelia infections cause malfunctioning of the
immune system. The presence of certain co-infections can complicate
things further. Borrelia can go into cyst form which reduces the
immune response. They can change to an intracellular, cell wall
deficient form which cannot be detected by antibodies as there is no
cell wall. The antibodies can form to become immune complexes, and so
not detectable by the test. Spirochaetes can be encapsulated in host
tissue (lymphocytic cell walls) remaining undetected by the immune
system. Borrelia like to be deep in a hosts tissue, especially tissue
with a very poor blood supply. In studies they have been extracted
from deep inside tendons. It is accepted that any blood test taken
following a recent bite will most likely return negative, as the
immune system will not have had sufficient time to mount a response.
Similarly it is known that in the chronic form of infection the human
immune response can be suppressed.
The Centre for disease control in the US states that "there is no
reliable test for Lyme disease at this time". Diagnosis must be made
by clinical methods. Risk of bite must be taken into account but even
if the patient does not recall the bite, rash or seeing a tick, this
disease should be given serious consideration.
How does this affect you?
Infected questing ticks have been found from the remote Isles of
Scotland, in popular London public parks and throughout many other
European city centre environments. Where there are animals there will
be ticks. In well planted gardens, shrubberies, grassy edges,
paddocks and hedgerows you will find ticks. In wooded areas,
grasslands, meadows, even buildings that support a large population
of roosting birds, ticks will be found.
If you consider that a spider-like nymph tick can be as small as a
pinhead it is safe to say that the majority of hosts could be bitten
without knowing. The tick will feed to full engorgement and drop off
with the host never having realized. Many people who have previously
been diagnosed as suffering from chronic fatigue syndrome, M.E.,
Fibromyalgia are now testing positive for Borreliosis and often other
tick-borne infections. Many of them have no recollection of a bite or
In the world of animal husbandry workers are at risk. In fact any
outdoor groups are at higher risk. Many national park rangers are
aware and concerned about the rise in tick numbers. The Ramblers
Association regularly warns walkers of the dangers of tick-borne
How can you protect yourself?
The first defence is to not allow ticks to attach.
Walk in the centre of woodland paths to minimize tick encounters on
overhanging grass and brush.
Tuck trousers into socks so any ticks that climb on will crawl on the
outside and be less likely to bite. Light coloured clothing should
be worn so the ticks will be easier to spot. Smooth materials such as
windbreakers are harder for ticks to grab onto. Consideration should
also be given to clothing with elasticised or drawstring toggles at
the ankles, wrists and waist areas.
When working in dense undergrowth likely to tug at clothing proper
leg/shin garters or alternatively duct tape could also be used to yet
further reduce possible opportunity for tick bites.
Tick repellents that contain "permethrin" can be sprayed onto
clothing. Spray the clothes before they're put on, and let them dry
Do not apply this chemical directly to the skin.
Remember that all types of domestic, farmyard and exotic animals are
also vulnerable to ticks. For domestic animals there are many
proprietary prepared products, such as collars and powders. For
farmyard animals the recent reintroduction of "dipping" once again
allows greater control and eradication of infested animals. Exotic
animals can also be treated in a similar fashion with appropriate
Ticks are very intolerant of being dried out. After being outdoors
in an infested area, place clothes in the dryer on high heat setting
for an hour to kill any ticks that may still be present. Keep outdoor
clothing in a tied plastic bag until it can be laundered.
Insect repellents that contain "DEET" are effective when applied to
the arms, legs, and around the neck. You can wear wrist and ankle
bands sprayed with repellent.
Do not use any repellent over wide areas of the body, as they can be
absorbed causing toxicity. Do not use a product that contains more
than 50% DEET; 25% concentrations are preferred. Use caution when
treating small children, as they are more susceptible to toxicity.
This repellent evaporates quickly and must be reapplied frequently.
Regular checks should be performed, and while ticks can attach
anywhere, there are certain areas more preferable where blood is
closer to the surface of the skin and it is warm and secure. The tick
will choose a place that it is not at risk of being brushed off
easily and where it can remain undetected. On humans ticks are most
commonly found feeding on areas such as - the backs of knees, groin
area, under the arms and on the scalp.
What to do if you find an attached tick.
1. Use fine-tipped tweezers or a bespoke tick removal device, these
are available from veterinary or internet suppliers.
2. Grasp the tick as close to the skin surface as possible and pull
upward with steady, even pressure. Do not twist or jerk the tick;
this may cause the mouthparts to break off and remain in the skin.
(If this happens, remove mouthparts with tweezers.)
3. Do not squeeze, crush, or puncture the body of the tick because
its fluids (saliva & gut contents) may contain infectious organisms.
4. Do not handle the tick with bare hands because infectious agents
may enter through mucous membranes or breaks in the skin. This
precaution is particularly directed to individuals who remove ticks
from domestic animals with unprotected fingers.
5. After removing the tick, thoroughly disinfect the bite site and
wash your hands with soap and water.
6. You may wish to save the tick for identification in case you
become ill within 2 to 3 weeks. Your doctor can use the information
to assist in making an accurate diagnosis. Place the tick in a
plastic bag and put it in your freezer. Write the date of the bite on
a piece of paper with a pencil and place it in the bag.
Note: Do not use petroleum jelly or burn the tick as this will
stimulate it to release additional saliva, increasing the chances of
If you find a tick attached, remove it as per instructions and keep
it for possible testing. Consult your GP. Keep a record of any
symptoms and photograph any rashes.
There are several useful websites that you can visit if you suspect
that you are infected or to find out more about tick-borne diseases.
On a personal note, I would like to add that all my life I have
worked with animals. I was a horse woman, zoo keeper and have always
had animals both domestic and exotic. I never suspected that I had
Lyme disease. I knew nothing about it. Being bitten by insects was
just part of daily life.
It wasn't until I became consistently ill and the doctors could find
no reason for my various aches, pains and ailments that I began to
suspect a zoonotic infection.
I was diagnosed in 1993 with Lyme disease and treated with
antibiotics. I thought that was the end of it. By 1998 I could barely
walk and by 2001 I was paralysed by transverse myelitis. I also
suffered an encephalopathy (swelling of the brain), which has left me
with permanent neurological damage. I am wheelchair bound and
dependant on a full time care assistant. Don't let this happen to you.
The fact is that in today's climate and with the ease of human and
animal trafficking the spread of disease is inevitable. Many of these
bacteria are becoming immune to treatments. Field workers - whether
keepers, grounds maintenance, golfers, riders, ramblers, scouts or
any of the groups in contact with nature need to be aware of the ease
in which they could find themselves very ill or permanently disabled.
The risk is very real.
Take preventative measures and stay safe in your work and leisure
' BADA-UK' (Borreliosis and Associated Diseases Awareness-UK) and we
have a website, http://www.bada-uk.org if anyone wishes for further
information or we can be contacted at firstname.lastname@example.org if