Enhancement of Risk of Tick-Borne Infection: Environmental and Parasitological Aspects of the Problem

The appearance of phenotypic (and probably genetic) exoskeleton anomalies in Ixodes ticks, first discovered and described elsewhere, seems to be a global phenomenon clearly related to environment pollution by heavy metal ions. These external markers of cadmium accumulation in the tick indicate an enhanced risk of tick-borne infection related to an increased vectorial capacity. This manifests itself in the ability of infected ticks both to quest longer and to show increased locomotory activity (hunting) compared with normal ticks. Ticks with exoskeleton anomalies show a greater susceptibility to different microorganisms, including tick-borne pathogens, and more intense pathogen replication with a higher prevalence of multi-infection.