Zoonotic infections in semi-domesticated eurasian tundra reindeer (Rangifer tarandus tarandus) in Fennoscandia - a review.

Eurasian tundra reindeer (Rangifer tarandus tarandus) make up the basis for reindeer herding in Norway, Sweden and Finland, hosting about 640 000 animals. The animals are mostly free-ranging, with the exception of a few seasonal gatherings. Loss and fragmentation of pastures due to other types of land use, together with climate change and even conservation of predators, are challenging reindeer herding, leading to recent mitigations such as increased feeding. Whereas the average Norwegian consumes about 300 gr/person/year of reindeer meat, Sweden about 100 gr/person/year and Finland about 400 gr/person/year, reindeer meat and products constitutes a much larger part of the diet to members of herding communities. Preparing reindeer meat with no thorough heat treatment (e.g., drying, smoking, curing or raw consumption) can be found in many arctic and sub-arctic people's cultures, and interest for reindeer meat that is not heat-treated has also grown (e.g., carpaccio-style), which can dramatically impact pathogen transmission. There is a wide range of zoonotic parasites, bacteria and viruses that potentially can be transferred from reindeer to human, but it can be concluded that the zoonotic threat from close contact with reindeer or the consumption of reindeer meat and products thereof currently is of restricted magnitude. However, due to the challenges that reindeer populations are facing and the mitigation by increased feeding, the infection biology of zoonotic infections may change and we may face emerging diseases (i.e., pathogens new to the host and region), such as the recently appearing prion disease, Chronic wasting disease (CWD), and re-emerging diseases, such as the alimentary form of necrobacillosis.