In some examples, a pathogen detection sensor includes an electrical circuit changeable from a first impedance state to a second impedance state in response to a change in the presence of pathogens (e.g., in response to pathogen growth). A substrate of a vascular access includes at least a part of the pathogen detection sensor, such as, for example, part of the electrical circuit. In this way, the pathogen detection sensor may be positionable proximate to a vascular access site in order to detect the presence of pathogens at or near a vascular access site of a patient.
