Avalon and Clo Mor: Two New Sakhalin Group Viruses from the North Atlantic1

Two new members of the Sakhalin serogroup were identified by complement-fixation tests. Avalon (prototype CanAr 173) was isolated from 3 lots of Ixodes uriae and the blood of a Herring Gull (Larus argentatus) chick collected in a Common Puffin (Fratercula arctica) colony on Great Island, Newfoundland, Canada. Clo Mor (prototype ScotAr 7) was recovered from a pool of I. uriae collected in a Common Murre (Uria aalge) colony at Clo Mor, Cape Wrath, Scotland. Both viruses are sensitive to lipid solvents, resistant to acidic pH, and do not hemagglutinate goose erythrocytes. Biological characteristics of both viruses in selected laboratory animals by various inoculation routes are reported. Viremia was demonstrated in suckling mice inoculated by peripheral routes with Clo Mor, but not Avalon, virus; viremia was not detected in weanling mice or baby chicks. Neither virus replicated in Aedes aegvpti, Culex pipiens quinquefasciatus, or Anopheles quadrimaculatus following intrathoracic inoculation. Neutralizing antibody to Avalon, but not Clo Mor, virus was demonstrated in L. argentatus, F. arctica, and Oceanodroma leucorhoa on Great Island. Antigenic, physicochemical, and ecological properties of the serogroup are discussed.