Chapter 3: Transmission / Natural cycle

Abstract

• The natural cycle of the TBE virus is dependent on vector ticks and their hosts. • Enzootic cycles vary between different habitats and involve sympatric tick vector and host species. • There are differing transmission cycles in varying environments, from cold northern coniferous forests to temperate central European forests. • Within a natural transmission cycle there are complex differing transmission possibilities – tick to tick (transovarial, sexual), host to tick (viremic), host to host and transstadial persistence. • The complexity of natural transmission cycles is inadequately explored and poorly understood.