Rationale: Although Lyme disease is the most common tick-borne disease in the U.S., co-infections with multiple microbes from a tick bite is an increasing risk for humans because the¿deer¿ticks that transmit Lyme may transmit diverse pathogens including Babesia microti, Borrelia miyamotoi, Anaplasma phagocytophilum, and Powassan virus. Despite the increasing prevalence of co-infection with Lyme and Babesia, very little is known about the impact of co-infection on the outcomes or long-term symptoms in Lyme disease. About 10% of Lyme patients also develop post-treatment Lyme disease syndrome, which is poorly understood but is associated with long-term debilitating symptoms. Diagnostics capable of differentiating active Lyme disease or Post-treatment Lyme disease syndrome are not available. This gap is a serious problem for treatment including whether a pathological host response or the pathogen should be targeted. We have developed a biobank of human samples with tick-borne diseases for research purposes to allows us to begin to address these crucial diagnostic and treatment gaps.

Scientific Objective: The goal of the proposal is to evaluate the impact of co-infection with Babesia microti on Lyme disease patients including active disease and post-treatment Lyme disease syndrome. This includes the identification of markers in the blood that can explain the reason behind the long-term symptoms in Lyme as well as to inform effective treatment. Currently, long-term symptoms after Lyme are prolonged antibiotic treatment, which is often of limited effectiveness. Furthermore, the impact of co-infection with other tick-borne pathogens on Lyme disease outcomes will be determined to both better inform treatment and disease pathology.

Relevance: The proposal is directly relevant to multiple critical gaps in diagnostics for Lyme disease, including (1) Development of a diagnostic biomarker panel for Lyme and/or other tick-borne diseases, (2) Approaches capable of distinguishing active infection and previous exposure, and/or monitoring response to treatment, and (3) Innovative approaches that provide diagnosis for a single or multiple tick-borne infection.

Specific Aim 1: To evaluate the impact of Babesia co-infection with Lyme disease on skin and systemic infection. We will use human samples from skin and blood on initial infection and during 1 and 6 months follow up to identify important differences in the person infected that result in severe disease versus mild disease.

Specific Aim 2: To determine if co-infection with Babesia species¿impacts Lyme disease severity,¿including long-term symptoms in Lyme. We will follow up Lyme patients with babesia up to 6 months to study the differences of single and co-infection in long-term symptoms in Lyme disease.

Specific Aim 3: To test the hypothesis that a host signature or other clinical factors¿are associated with long-term Lyme symptoms after single or co-infections.¿ We will identify individuals with Lyme as well as those with Lyme plus co-infections including babesiosis that present with long-term Lyme symptoms as evaluated by a validated quality of life and neurological questionnaire.

Innovation: Our studies are highly innovative. They will apply state-of-the-art scientific advances in tools to analyze the genes that are expressed during Lyme and Babesia human infection and how their changes in expression impact in the long-term symptoms of Lyme. This has never been done before. This is a highly innovative approach of evaluating the whole peripheral blood environment from humans (which is seen in clinical practice) including different types of RNA to examine host and pathogen effects of the most two important human tick-borne diseases, Lyme and babesiosis, as well as to predict their complications in this longitudinal group of patients. To ensure the translation of discovery to clinical application, we include comprehensive descriptions of clinical pathophysiological features of Lyme disease and babesiosis.

Ultimate Applicability of the Research: These studies will identify a blood biomarker panel specific for Lyme disease and likely a host-biomarker set that can distinguish acute infection from resolved infection and long-term symptoms. The proposed studies may also identify transcriptome profiles that are correlative with long-term sequelae associated with Lyme and other tick-borne diseases that will provide the foundation for better inform treatment.