Infection and Immunity, Apr. 2025. Ixodes scapularis ticks are an important vector for at least seven tick-borne human pathogens, including a North American Lyme disease spirochete, Borrelia burgdorferi. The ability for these ticks to survive in nature is credited, in part, to their ability to feed on a variety of hosts without triggering an immune response capable of preventing tick feeding. While the ability of nymphal ticks to feed on a variety of hosts has been well documented, the host-parasite interactions between larval I. scapularis and different vertebrate hosts are relatively unexplo…

Plos Pathogens, Dec. 2025. Lyme disease is caused by the host-adapted spirochete Borrelia burgdorferi. With a genome of only 1.5 mbp, B. burgdorferi is dependent on metabolites scavenged from their vertebrate and invertebrate hosts for growth. These scavenged nutrients include several lipid precursors: the spirochete is auxotrophic for fatty acids and cholesterol, and also accumulates environmental phospholipids. Comprehensive lipidomic analysis of B. burgdorferi by LC MS/MS was used to identify previously undescribed membrane components. These include some likely scavenged from the culture me…

Frontiers in Immunology, Nov 2025. Introduction: Clinical presentation of Lyme disease is largely due to host immune response to infection. Previously, we identified a variant (1805GG) in the TLR1 gene, a key immune sensor for Borrelia burgdorferi, which was associated with excessive inflammation and severe disease. Herein we examined the mechanism by which this variant leads to dysregulated immunity.

Methods: We found that patients with post-infectious Lyme arthritis, a condition characterized by marked persistent synovitis in joints, have a higher frequency of TLR1-1805GG compared to those …

Ticks and Tick-borne Diseases, Nov 2025. Tolerance and resistance are two host eco-immunological strategies in response to microparasite invasion. In the strategy of “resistance”, host responses are induced to decrease microparasite replication while the “tolerance” strategy allows hosts coexistence with microparasites by minimizing responses to avoid immune-mediated damage. The causative agent of Lyme disease is a group of genotypically diverse bacterial species, Borrelia burgdorferi sensu lato (Bb), which is transmitted by Ixodes ticks and persists in different reservoir animals. In North Am…

Clinical Infectious Diseases, Dec 2025. Description: Babesiosis is a tick-borne disease that is endemic in the United States (US). The major species, Babesia microti, is readily transmissible via blood transfusion. Since 2019, blood donors in 14 US states and Washington DC have been routinely screened for Babesia infection using highly sensitive and specific nucleic acid testing (NAT). Currently, there are no recommendations regarding the management of asymptomatic blood donors who test positive for Babesia.

Methods: A multidisciplinary expert panel was convened to develop guidance for the ma…

Annals of Internal Medicine 2025. Lyme disease, caused by Borrelia burgdorferi, is the most common vector-borne disease in the United States, and the range of its tick vector continues to expand. Most Lyme disease cases are diagnosed with the onset of the erythema migrans rashes, which can be single or multiple and vary from a homogeneous erythema to bull’s-eye patterns. Serologic antibody testing is of low sensitivity at onset but becomes highly sensitive after a few weeks. Early dissemination may lead to neurologic and cardiac complications. Mono- or oligoarticular arthritis may develop in …

Science Translational Medicine March 2025. Ixodes scapularis is a primary vector of tick-borne pathogens in North America. Repeated exposure to these ticks can induce a humoral response to tick antigens and acquired tick resistance. However, identifying antigens contributing to this resistance is challenging because of the vast number of I. scapularis proteins secreted during feeding. To address this, we developed I. scapularis rapid extracellular antigen monitoring (IscREAM), a technique to detect antibody responses to more than 3000 tick antigens. We validated IscREAM with immunoglobulin G (…

Journal of Infectious Diseases, 2026. Lyme disease spirochetes are maintained in natural reservoirs before spilling over into human populations. Targeting these reservoirs with vaccinations or antibiotics could impact the Borrelia burgdorferi enzootic cycle and reduce the risk of human Lyme disease. In this work we report that the narrow-spectrum antibiotic hygromycin A is sufficient to disrupt B burgdorferi transmission from the main eastern US reservoir, Peromyscus leucopus, to ticks. Additionally, hygromycin A-containing baits can clear B burgdorferi from P leucopus. These studies lay the …

Many of the diverse tick-borne diseases (TBD) in the US appear to be increasing in incidence, leading to concern that factors such as climate change may create challenging scenarios. The 18 TBD and 1 syndrome that cause illnesses in US residents present varying public health burdens (Table). For US clinicians, the most common TBD of concern is Lyme disease (estimated at about 476 000 cases each year1), with babesiosis, human granulocytic anaplasmosis (HGA), Rocky Mountain spotted fever, monocytic ehrlichiosis (HME), and alpha gal allergy (ie, red meat allergy) annually accounting for hundred…

Survivors of Powassan encephalitis often have persistent neurological disease. A new mouse model replicates some elements of the human disease and demonstrates the presence of viral RNA in the brain as well as myelitis more than 2 mo after the acute infection. The related tick-borne encephalitis and West Nile Neuroinvasive Disease (WNND) also have common neurological sequelae, and models for these better-studied diseases provide evidence for prolonged virus, RNA, and inflammation in some cases, in addition to damage from the acute encephalitic disease. A better understanding of the…