An introduction to the terminology, epidemiology and ecology of Lyme disease and related tick-borne disorders, this presentation looks at the burden of illness in both human and monetary terms, the role of vector and host factors, the nature of the clinical challenges in these diagnoses, and the evidence-based approach presented in this ILADS Fundamentals Course.

This section presents the evidence for assessing and managing known Ixodes tick bites. Then, using case illustrations, it explores the diagnosis and management of early Lyme disease with and without erythema migrans as a presenting symptom.

Using case illustrations, and building upon preceding presentations, this segment navigates the assessment, diagnosis, and management of later manifestations of Lyme borreliosis, with attention to the differential diagnosis, clinical and laboratory evaluation, and pathophysiology of disseminated disease. It provides an evidence base to support treatment recommendations. Similarly, this segment goes on to explore the evaluation, differential diagnosis, and management of patients who remain ill or relapse after treatment for Lyme disease, as well as foundational pathophysiology and evidence.

The simultaneous infection of a host by multiple pathogens is the subject of this presentation, which addresses clinical presentation, evaluation and management of three common co-infections. The impact of the co-occurrence of these infections on severity, treatment combinations, and duration of treatment is explored.

To round out our discussion of co-infections, this presentation takes a close look at the bacterial infections Ehrlichiosis, Anaplasmosis, and Rocky Mountain Spotted Fever, as well as those caused by Mycoplasma and Chlamydia—organisms sometimes mistaken for viruses because of their unusual intracellular behavior.

Examine the psychiatric and neurological manifestations of tick-borne diseases, particularly Lyme borreliosis, highlighting how immune disruption and persistent infection can lead to depression, anxiety, suicidality, cognitive decline, and dementia, while also addressing the psychosocial toll on patients and caregivers. Treatment strategies emphasize a comprehensive approach that integrates antimicrobials, psychotropics, immune support, and targeted symptom management.

Explore the unique risks children face with tick-borne diseases, which can cause fatigue, cognitive decline, psychiatric symptoms, and developmental delays, leading to frequent misdiagnosis, long delays in care, and the overlap with conditions like PANS/PANDAS and autism spectrum disorders. Case studies demonstrate how timely, tailored treatment can significantly improve outcomes.

Review the principles and limitations of current diagnostic tools for tick-borne diseases, including serology, immunoblots, PCR, FISH, and T-cell assays. Explore the challenges of sensitivity, specificity, species coverage, and evolving immune responses, while emphasizing the need for complementary testing strategies and careful clinical interpretation.

The final course module features experienced clinicians sharing case studies and best practices in the diagnosis and treatment of patients presenting with late-stage, complex or multiple tick-borne illnesses.