Avian spirochetosis: natural transmission by Argas (Persicargas) sanchezi (Ixodoidea: argasidae) and existence of different serologic and immunologic types of Borrelia anserina in the United States.

A mild strain of Borrelia anserina was transmitted to chicks by an argasid tick identified as Argas (Persicargas)sanchezi Dugès, 1887. Disease was transmitted regularly to chicks less than 2 to 3 weeks old, and rarely to chicks 4 weeks old or older. This spirochete isolate was demonstrated to be immunologically and serologically diverse from an isolate obtained earlier in Arizona. This is the first report of transmission of B anserina by A(P) sanchezi and of the presence of different serologic and immunologic isolates of this spirochete in the United States.