Survey of Q-fever agglutinins in birds and small rodents in Northern California, 1975-76.

Serum samples from 15 species of rodents and 33 species of birds were tested for agglutinins against Coxiella burnetii by the microagglutination test. Of 759 rodents tested, 21 (3%) were seropositive. Antibody positive rodents included muskrats, Ondatra zebethica, (11%), Rattus spp. (10%), Beechey ground squirrels, Otospermophilus beecheyi, (6%), wood rats, Neotoma fuscipes, (5%), and Peromyscus spp. (2%). Of 583 birds tested, 118 (20%) were seropositive. This included white crowned sparrows, Zonotrichia leucophrys, gold crowned sparrows, Z. atricapilla, and English sparrows, Passer domesticus, (68% in the composite); coots, Fulica americana, (29%); blackbirds, Euphagus cyanocephalus, (33%); crows, Corvus brachyrhyncos, (29%); robins, Turdus migratorius, (16%); pigeons, Columba fasciata, (10%); and mallard ducks, Anas platyrhynchos, (7%). There was a tendency for the seropositive animals to have been collected in the vicinity of endemically infected livestock.