Imported vector- and rodent-borne virus infections--an introduction.

Travel is a potent force in the emergence of virus infections. Migration of humans and animals has been the pathway for disseminating virus diseases throughout history. In recent years, dengue virus has been identified as the most important travel-related, vector-borne virus disease. Other vector-borne virus infections, such as sandfly fever, Rift Valley fever, chikungunya fever and Japanese encephalitis, have been diagnosed in travelers returning from endemic areas. Crimean-Congo haemorrhagic fever may not only be imported by infected live stock, but also by travelers. Of rodent-borne virus infections, Lassa fever has been diagnosed occasionally in travelers returning from endemic areas. The potential impact of imported filoviruses is currently discussed.