Aransas Bay Virus, a New Arbovirus of the Upolu Serogroup from Ornithodoros Capensis (Acari: Argasidae) in Coastal Texas

Abstract

In 1975, three strains of a new virus were isolated from 164 pools of Ornithodoros (Alectorobius) capensis ticks collected from aquatic birds' nests on coastal islands of southern Texas. Isolation, identification and characterization of the new virus, Aransas Bay are described. Complement-fixation tests revealed a relationship of this agent with Upolu virus, known only from Australia, but reactions were significantly stronger in one direction than in the other. Both viruses react markedly in immunofluorescence and neutralization tests with Aransas Bay immune ascitic fluid (AF), but potent immune AF prepared from Upolu virus reacts only slightly or not at all in these tests with the new virus. Repeated attempts to produce a hemagglutinin from Aransas Bay virus have failed. The new agent is an RNA virus, between 100 and 220 nm in size, possesses essential lipids, and is sensitive to exposure to heat and acid. It is lethal for suckling and weanling mice by intracerebral and intraperitoneal routes of inoculation, and infects Vero cells with the production of cylopathic effects and plaques. A new serological group, Upolu, is proposed. Soldado virus (Hughes serogroup) was also identified in ticks from this study.