In addition, we explored use of the VecTest with swabs from the cloaca, feather pulp, and internal tissues to determine whether use of other antigen sources might improve the sensitivity of the test.
Feather pulp was taken by pulling a blood feather from the wing or tail and then expressing the pulp onto a swab.
VecTest of feather pulp for 43 RT-PCR-positive corvids (37 American Crows, 5 Blue Jays, 1 Fish Crow) identified WNV in 36 (84%) of the birds tested.
Recent findings have shown vascular flight feather pulp of corvids to be a superior source for WNV isolation by culture (12).
The cloacal swab, kidney and spleen pool, and feather pulp were the source of WNV in 38%, 43%, and 77%, respectively, of the carcasses.
Previous studies have shown that WNV may be isolated from feather pulp of experimentally infected crows (National Wildlife Health Center, unpub, data).
Kidney and spleen pools, cloacal swab, and feather pulp were collected from each of these 84 birds received from the following nine states: Alabama, Illinois, Kansas, Maryland, Missouri, North Dakota, Pennsylvania, Texas, and Virginia.