Following a tick bite: double infections by tick-borne encephalitis virus and the spirochete Borrelia and other potential multiple infections.

In Central Europe and large parts of Asia, tick-borne-encephalitis (TBE) and Lyme borreliosis caused by the spirochetal bacterium of the genus Borrelia are among the most common diseases transmitted by the bite of a tick. When in regions with overlapping TBE virus and Borrelia endemicity, a tick bite causes the victim to become ill, it is important that appropriate serological and other laboratory investigations form part of the differential diagnosis. Account must always be taken of the fact that a tick bite may be followed by a double infection with the TBE virus and Borrelia. For this reason, a comprehensive diagnostic work-up aimed at detecting co-infection by both pathogens, even when the tick bite occurs in an endemic region for both pathogens but the initial clinical symptoms suggest an infection with only one of the two pathogens. The present article discusses a number of published cases of a co-infection with TBE virus and Borrelia and other potential multiple infections.