Development of precipitating antibody in chickens experimentally infested with northern fowl mite, Ornithonyssus sylviarum (Acari: Macronyssidae).

In order to examine the immune response of chickens to different population levels of mites, a microscopic slide modification of the Ouchterlony double-gel diffusion technique was adopted for examination of circulating antibody against the extract of northern fowl mite, Ornithonyssus sylviarum. Precipitating antibodies were detected in all the chickens infested with the mite. One to three clearly defined precipitation lines appeared in almost all the serum samples of infested birds. Titers of antibody correlated with population levels of the mite on chickens, and no differences in antibody development of hens and roosters were distinguished. These results suggest that the titration of precipitating antibodies appears to be useful for the assessment of mite population levels on chickens.