Tick-borne diseases in a one health perspective, host and pathogen interplays The search for TBE virus and related pathogens

TBEV (Tick-borne encephalitis virus) and Borrelia burgdorferi sensu lato are among the most important vector-borne diseases that are emerging. They are the main diseases transmitted by Ixodes ricinus ticks in Europe. I. ricinus is known to transmit other pathogenic microorganisms like- louping ill virus, Anaplasma phagocytophilum, and endosymbionts like-Wolbachia pipientis and Midichloria mitochondrii that may have an influence of the pathogenesis in humans and animals. Factors like climate change, human behavior and migrating animals are involved in the distribution of diseases. The main route of disease transmission is through tick bites, but infection through alimentary system for serious infectious agents like TBEV and wild and production animals as sentinels for transmission. The knowledge of natural foci and prevalence of these infectious microorganisms is important for risk assessment of human disease. Preliminary results from 3240 nymph and 234 adult ticks were collected from six location sites of three counties in Norway. The tick samples were analyzed and minimum infection rate/prevalence was calculated. Body fluids of the host animals are valuable epidemiological parameters for TBEV like cow milk and serum from sheep and cows. This study confirms the existence of TBEV endemic foci compared to earlier study. The prevalence of B. burgdorferi s.l., were analyzed in adult ticks while the prevalence of A. phagocytophilum, W. pipientis, M. mitochondrii were studied in nymph and adults. TBEV were detected in a new location in Hordaland county. The detection of TBEV in milk and serum from cows has never been reported in Norway before.