Tuesday, 20 August 2013
Lyme disease – a serious public health issue, distracted by those that make it appear even worse.
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.