Bill C-442: Shining the limelight on the Lyme-like?

1Department of Medicine, Royal Inland Hospital, Kamloops, British Columbia; 2Departments of Medicine, Critical Care Medicine, Pathology and Laboratory Medicine, and Community Health Sciences, University of Calgary, Calgary, Alberta; 3Department of Microbiology-Infectious Diseases, Université de Sherbrooke, Sherbrooke, Quebec Correspondence: Dr Kevin B Laupland, Royal Inland Hospital, 311 Columbia Street, Kamloops, British Columbia V2C 2T1. Telephone 250-374-5111, e-mail [email protected] On June 11, 2014, The House of Commons passed Bill C-442, An Act Respecting a Federal Framework on Lyme Disease (1), and on June 12, 2014, this was introduced as a First Reading into the Senate. This act is a private members’ bill introduced by Member of Parliament Elizabeth May and aims to develop a Federal plan surrounding the diagnosis and management of Lyme disease in Canada. The Federal Framework on Lyme disease dictates that a conference be held with provincial and territorial ministers and a range of stakeholders to establish an enhanced surveillance program and to develop prevention, identification and management guidelines, and standardized educational materials for public health care providers in Canada. As detailed in the preamble (1), motivation for this bill stems from concerns that increasing cases of Lyme disease are expected to occur in the ensuing years due to the evolving distribution of the vector blacklegged (Ixodes scapularis) and western blacklegged (Ixodes pacificus) ticks, and the spread of the pathogen Borrelia burgdorferi in Canada. In addition, the Bill C-442 preamble asserts that current diagnostic and management approaches are inadequate and explicitly claims that use of current Canadian guidelines “severely limit the diagnosis of acute Lyme disease and deny the existence of continuing infection, thus abandoning sick people with a treatable illness” (1). Lyme disease has been a nationally reportable disease in Canada since 2009. Surveillance data from the Public Health Agency of Canada indicate that the vectors and pathogen are established in parts of New Brunswick and Nova Scotia, southeastern Quebec, southern and eastern Ontario, southeastern Manitoba and southern British Columbia (2). Human disease cases reported for the first five years of national surveillance have significantly increased annually and are as follows: 2009 (128 cases), 2010 (132 cases), 2011 (258 cases), 2012 (315 cases), and 2013 (anticipated ≥500 cases pending confirmation) (2). Field surveillance and modelling studies have identified existing confirmed and suspected endemic risk areas and potential future risk areas within Canada (2-4). In fact, confirmed populations of I scapularis increased from one to 13 regions between 1997 and 2006 (5). While predicting areas of future risk is difficult and challenged by many variables including climate change, habitat, distribution of wild animal reservoirs and bird migration routes, potential marked further increased distribution of the vector and, hence, risk areas for Lyme disease in the coming decades is reasonably expected (4,6). Lyme disease has a broad range of potential symptoms, signs and severity. Early localized infection may be asymptomatic, associated with a nonspecific flu-like illness or, most commonly, associated with the presence of erythema migrans (7,8). Untreated cases may then progress to disseminated disease manifested by cardiac, neurological, dermatological and/or rheumatological abnormalities. Appropriate antimicrobial therapy with doxycycline, penicillins, and secondor third-generation cephalosporins is highly effective at resolving clinical disease and eradicating the organism (9-11). However, in a minority of patients following successful treatment, prolonged symptoms of fatigue, musculoskeletal and neurocognitive complaints, and/or adverse effects on functioning and quality of life occur (12,13). When persistent over a prolonged period of time (ie, six months), this self-reported symptom complex is referred to as post-treatment Lyme disease syndrome (14). It is important to recognize that post-treatment Lyme disease syndrome occurs in the absence of compelling evidence of ongoing or chronic infection due to B burgdorferi (12,15). However, patients remain at risk for reinfection and development of second and further incident episodes of Lyme disease (16). Lyme disease is an important and emerging infection in Canada that warrants our attention. The Public Health Agency of Canada has developed an action plan (initiated March 2014) that includes the three pillars of: engagement, education and awareness; surveillance, prevention and control; and research and diagnosis (17). Bill C-442 aims to provide further federal support for a Lyme disease strategy. While we support an enhanced strategy for Lyme disease surveillance and management in Canada, Bill C-442 raises several important points worthy of discussion. First, while we recognize its present and potential future importance, we must consider the burden of Lyme disease in context with other community-onset bacterial diseases in Canada. The most recent estimates of the number of Lyme diseases cases in Canada is approximately 500; considering a national population of 35.2 million residents, this translates to an annual incidence rate of approximately 1.4 per 100,000 population (2,18). Death from Lyme disease is uncommon. As an example to place this rate in context, community-onset bloodstream infection occurs at a rate of approximately 100 per 100,000 per year and is associated with a case-fatality rate of approximately 12% (19). In other words, the current rate of deaths associated with community-onset bloodstream infection is 10-fold higher than the overall incidence of Lyme disease in Canada. Furthermore, the emergence of antimicrobial-resistant pathogens poses a far greater threat to the present and future health of Canadians (20). While in general we welcome any enhanced support for infectious diseases surveillance, management and research, we do question prioritization of limited resources in preference to other infections that have an objectively far greater burden of disease in Canada. Second, the bill preamble states that diagnostics for Lyme disease are inadequate and it proposes to correct this problem. The present diagnostic approach in Canada generally involves clinical assessment (including exposure risk and clinical features) and use of a two-step enzyme immunoassay and confirmatory Western blot serological testing strategy (21). Serological testing is known to have a low sensitivity early in disease (ie, <1 month) and diagnosis and treatment based on clinical features alone (ie, presence of erythema migrans) is recommended. Later in the disease, the enzyme immunoassay is highly sensitive but risks false positives, such that confirmatory Western blot with interpretation according to standardized criteria is used (21). As with all infectious diseases, diagnostic tests alone are never perfect and false positives and negatives may occur. There are ≥70 available serological tests that have been approved for diagnosing Lyme disease in North aduLt infeCtiouS diSeaSeS noteS