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
by Eve
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
eradicate.
Common co-infections
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
guarantee
regurgitation.
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.
Symptoms
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.
Testing
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
a rash.
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
disease.
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
first.
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
chemical
treatments.
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
transition.
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
activities.
' 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 bada-uk@hotmail.co.uk if
needed.
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