Laboratory Methods for the Diagnosis of Borreliosis with a Focus on Point-of-Care Testing

Lyme borreliosis is a clinically heterogeneous tick-borne infection caused by members of the Borrelia burgdorferi sensu lato complex. Its diagnosis remains difficult because early manifestations can be nonspecific, pathogen load in accessible specimens is low, and antibody responses are time-dependent. This manuscript reviews the biological background of borreliosis, including neuroborreliosis, and summarizes standard laboratory approaches such as cultivation, PCR, serology, and cerebrospinal fluid antibody index assessment. Special attention is given to decentralized diagnostic strategies, including point-of-care assays, LAMP-based nucleic acid amplification, lateral flow immunoassays, microfluidic devices, and biosensor platforms. Although direct detection of the pathogen or its components is attractive, it is limited by tissue tropism and low concentrations of Borrelia in blood. In contrast, antibody-based point-of-care testing appears more feasible and may support early screening, triage, and timely referral. Reliable validation, appropriate clinical interpretation, and integration with confirmatory laboratory diagnostics remain essential for safe clinical implementation.