TICK-BORNE DISEASES have rapidly become a serious and growing threat to public health in the United States. Despite many scientific unknowns, experts agree that the incidence and distribution of tick-borne diseases are increasing. Over the past 25 years, reports of Lyme disease have increased steadily with estimated annual cases approximating 300,000 (Hinckley et al., 2014; Nelson et al., 2015). The number of U.S. counties now considered to be of high incidence for Lyme disease has increased by more than 300% in the Northeastern states and by approximately 250% in the North-Central states. The Centers for Disease Control and Prevention (CDC) currently recognizes 18 tick-borne pathogens in the United States. However, researchers and health care practitioners continue to discover emerging disease agents and new medical conditions associated with tick bites.
While most Lyme disease patients who are diagnosed and treated early can fully recover, 10 to 20% of patients suffer from persistent symptoms, which for some are chronic and disabling. Studies indicate that Lyme disease costs approximately $1.3 billion each year in direct medical costs alone in the United States. A comprehensive understanding of the full economic and societal cost remains unknown. It is likely orders of magnitude higher and potentially a $50- to $100-billion-dollar problem for the United States, although more research is needed (Vanderhoof & Vanderhoof-Forschner, 1993; Zhang et al., 2006).
Prompt diagnosis and treatment of tick-borne diseases are crucial to prevent long-term complications. Today, available diagnostic tests can be inaccurate and complex to interpret, especially during the earliest stage of infection when treatment is most effective. Unlike in other infectious disease settings, tests to directly measure the presence of the infecting organism, such as cultures or tissue biopsies, are not available for some tick-borne diseases such as Lyme disease. This leaves physicians without the tools needed to diagnose; and without an accurate diagnosis, it is challenging for physicians to provide early treatment.
Persistent symptoms after treatment of Lyme disease can be severe, yet their cause(s) remains unknown and debated. There are currently no uniformly accepted or validated treatment options for patients with these chronic symptoms. As a result, uncertainty surrounding appropriate clinical care has led to polarization within the medical community, and patients are often left suffering in limbo without a clear path to illness resolution or even symptom management (Rebman et al., 2017). The lack of a clear path for treatment of persistent symptoms in some patients with Lyme disease and other tick-borne diseases not only amplifies patient suffering but also significantly increases health care costs.
This report outlines an integrated, multipronged approach to the growing public health challenges posed by tick-borne diseases in the United States. It contains nine main chapters, including Background; Methods; Epidemiology and Ecology; Prevention; Diagnosis; Treatment; Access to Care, Patient Outcomes; Looking Forward; and Conclusion. The Background and Methods chapters explain how the report was developed. The other chapters present the main challenges, key issues, and recommendations specific to the broader topics.
To understand tick-borne diseases, we need to first understand tick ecology and how ticks transmit diseases. Due to the lack of a coordinated national surveillance program, currently there are significant gaps in information on local distribution of infection-causing ticks, especially in regions beyond the Northeast and Upper Midwest. Nationwide, standardized approaches for tick, animal, and human surveillance are needed to understand the geographic distribution of infectious ticks in order to understand the spread of disease and predict where people are at risk. Advanced technologies and systematic studies are also needed to rapidly identify new disease agents that pose emergent risks to public health, including to the blood supply. Given that seven new tick-borne pathogens have been shown to infect people in the United States since 2004, this is a priority.
Effective prevention relies on multipronged strategies. To reduce exposure to ticks, we need a comprehensive understanding of the biological drivers behind the continued spread of tick-borne diseases, so that effective tick- and infection- control methods can be identified and validated. Need also exists for the transparent development of a safe, effective human vaccine to prevent Lyme disease, the most common of these illnesses. In the absence of effective strategies for controlling ticks and blocking the transmission of tick-borne pathogens, it is crucial to educate health care professionals and the public about tick-borne disease prevention, especially best practices for protection from tick bites. Outreach efforts to promote prevention and raise awareness among physicians and the public must be expanded at both the Federal and state level to ensure accurate, effective, and consistent messaging.
Clinical research priorities must include the development of new technologies and approaches to improve diagnosis of tick-borne diseases and monitor response to treatment. There is a critical need for sensitive and specific direct-pathogen detection strategies that are broad enough to cover multiple potential tick- borne pathogens. Understanding the etiology and pathogenesis of ongoing symptoms after initial treatment should be a clinical research priority. Investigations are also needed into the potential roles of immunologic responses, bacterial persistence, and coinfecting pathogens in order to design and test new therapies and, ultimately, improve outcomes and care for patients with ongoing symptoms.
Americans need help, yet progress has been hampered by a lack of attention at the Federal level and by divisions within the field. The recommendations in this 2018 report of the Tick- Borne Disease Working Group represent a long- term investment in tackling the rise of tick-borne diseases in this country. However, immediate changes are also required to help patients already suffering from tick-borne diseases; to protect them from discrimination; and to address the inflexible, inconsistent, and often unaffordable care that patients frequently encounter in the current health care system.
Increased Federal funding, prioritization, and leadership are needed to reverse the alarming trends associated with tick-borne diseases. Despite several decades of research, prevention, and educational activities, Federal funding for tick-borne diseases is less per new surveillance case than that of other diseases. The U.S. National Institutes of Health (NIH) and CDC spend $77,355 and $20,293, respectively, per new surveillance case of HIV/AIDS, and $36,063 and $11,459 per new case of hepatitis C virus, yet only $768 and $302 for each new case of Lyme disease. Federal funding for tick-borne diseases today is orders of magnitude lower, compared to other public health threats, and it has failed to increase as the problem has grown
It is also essential that funding and resources be allocated to support a comprehensive, interagency program to address the mounting challenges identified in this report. All research, prevention, and education initiatives should be inclusive of special populations such as children, who suffer disproportionately from tick-borne diseases. Patients whose lives continue to be disrupted by the lasting effects of these illnesses are counting on emerging scientific research, evidence-based policy, and the health care establishment—including the Federal Government with Congressional and Executive leadership—to provide solutions. We must act now.