Everyone would agree that in its worst manifestation (late
disseminated infection), it rivals the most complex of chronic infectious
diseases like syphilis. When caught
with early disseminated infection secondary to hematogenous spread its symptoms
are significant and sometimes devastating.
Caught early as localized infection (about the first month), the classic
erythema migrans present in three-quarters of cases can be readily
treated. Those without the classic skin
rash are more likely to proceed to the disseminated forms of illness.
The culprit is a bacteria transmitted in a tick bite. Ticks have to go through a complex life cycle
during which they are exposed to the bacteria in deer mice, and subsequently
attach to a human (deer are the preferred mammalian feed) for feeding during
which the bacteria is injected. It is
the Ioxides tick species follow this particular
life cycle, which is a relatively small tick and less likely to be noted than
some larger tick species that cause many fearful reactions. Its relative size may facilitate it not being
detected, as transmission generally requires at least 24 hours of attachment
before infection with the spirochetal bacteria has occurred.
Treatment requires prolonged antibiotics, and is most
effective when prescribed earlier. Those
with disseminated illness often developed persistent symptoms not associated
with persistent infection.
On this later point hinges the controversy. The long term symptoms of Lyme disease are
often associated with fatigue, achiness, and weakness. Very non-specific symptoms that can be
associated with a wide range of diagnosis, including chronic fatigue syndrome, fibromyalgia,
and depression. Distingushing between
different clinical syndromes can be challenging, and most of us would prefer to
have a clearly identified culprit to blame for our non-wellbeing. Ticks, bacteria and Lyme disease make for an
excellent target for such externalization of blame.
Those with similar symptoms can be the victims of unscrupulous
entrepreneurs or even just misguided health professionals with personal
biases. These victims are fuelled by
those with real chronic Lyme illnesses. The
symptoms and diagnosis being accepted frequently for long term disability and
other forms of support. A notorious inaccurate laboratory test likely
labelled thousands of people erroneously as long term “carriers” of Lyme
infection. Other health practitioners
that have blamed symptoms on a post-Lyme condition even where definitive Lyme
illness has not been identified.
CDC has recently reported that as many as 300,000 cases of
Lyme disease are diagnosed in the US each year.
The estimate based on multiple methodologies including serosurveys, medical claims, and self-reported
disease. CDC
report
While Lyme disease is less common in Canada, the incidence
is likely increasing. PHAC’s carefully worded site contains
excellent information PHAC
Lyme Q and A for general questions,
and health professionals and others can view more detailed information at PHAC Lyme for health
professionals . Notable are the maps
that document the risk areas for transmission, with moderate to high risk limited
to southern Ontario and Quebec, and areas in New Brunswick and Nova
Scotia. Low risk areas exist in PEI, Manitoba
and BC. Almost all reports acknowledge the
risk is changing and that climate change will likely increase Lyme disease and
tick prevalence in Canada.
While groups like the Canadian Lyme Foundation have
advocated long and hard for increasing the profile of Lyme illness, they have
done so by depending on less rigorous science.
In doing so, they have diluted what is otherwise a serious illness and
real threat for well over half of Canada’s population who live in risk
areas.
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