Tick-borne viruses associated with seabirds in North America and related islands.

About 18 tickborne viruses associated with seabirds are known from Canada, Mexico, the Antilles, and the United States, including its oceanic islands. Antigenic groups to which these viruses belong are Hughes, B, Sakhalin, Uukuniemi, Kemerovo, Nyamani and Quaranfil. Members of the last two groups are known in the Western Hemisphere only from Central Pacific Islands and may reflect intrusion of elements of the Australian Region. In the areas under discussion, antibody surveys have been minimal, but there is some indication of human exposure to agents of the Kemerovo group. Members of the Hughes, Nyamanini, and Quaranfil groups are all argasid tick viruses, largely tropical or subtropical in distribution, and associated particularly with gulls and terns (Laridae). The remainder, with the exception of Mono Lake (Kemerovo group, Chenuda Subgroup), which may be a virus of inland birds, are ixodid tick viruses associated mostly with seabirds of the polar or subpolar regions. All of these viruses are seen as acted upon by a common pattern of geographic and biotic factors that influences antigenic diversity of the virus and favors development of strong insular variants.