Volume 16, Number 8—August 2010
Research
Multiyear Surveillance for Avian Influenza Virus in Waterfowl from Wintering Grounds, Texas Coast, USA
Table A2
Apparent prevalence of avian influenza virus in various waterfowl and wetland-associated game bird species as determined by VI and real-time RT-PCR from cloacal swabs collected from hunter-harvested waterfowl, Texas mid–Gulf Coast, USA, September 2007–January 2008*
| Species |
No. tested |
Real-time RT-PCR,†
no. (%) |
VI,† no. (%) |
Isolate‡ |
| American wigeon (Anas americana) | 51 | 8 (15.7) | 0 | – |
| Fulvous whistling duck (Dendrocygna bicolor) | 14 | 1 (7.1) | 0 | – |
| Gadwall (Anas strepera) | 160 | 10 (6.3) | 1 (0.6) | H6N1 |
| Mottled duck (Anas fulvigula) | 26 | 1 (3.9) | 0 | – |
| Mottled duck x Mallard (A. fulvigula x A. platyrhynchos) | 2 | 1§ | 1§ | H6N8 |
| Northern pintail (Anas acuta) | 62 | 13 (21.0) | 3 (4.8) | H4N8, H10N3, H10N3/7 |
| Northern shoveler (Anas clypeata) | 239 | 38 (15.9) | 10 (4.2) | H4N2, H5N2 (2), H5N3, H6N2 (2), H10N2, H10N7, H11N9 (2) |
| Ring-necked duck (Aythya collaris) | 17 | 1 (5.9) | 0 | – |
| Ruddy duck (Oxyura jamaicensis) | 36 | 2 (5.6) | 1 (2.8) | H2N3 |
| Teal, blue-winged (Anas discors) | 1,213 | 155 (12.8) | 73 (6.0) | H1N1 (2), H2N8, H3N4, H3N6 (2), H3N8 (9), H4N1, H4N6 (17), H4N8 (6), H5N2 (2), H5N3 (2), H6N1, H7N1, H7N1/4, H7N4, H7N7 (5), H10N?, H10N3 (2), H10N3/7, H10N7 (7), H11N9 (3) |
| Teal, cinnamon (Anas cyanoptera) | 2 | 1§ | 1§ | H7N3 |
| Teal, green-winged (Anas crecca) | 464 | 38 (8.2) | 7 (1.5) | H5N2, H7N1/4, H7N3, H10N3, H10N3/7, H10N7, H11N9 |
| Snow goose (Chen eaerulescens) |
43 |
3 (7.0) |
0 |
– |
| Total¶ | 2,424 | 272 (11.2) | 97 (4.0) | – |
*VI, virus isolation; RT-PCR, reverse transcription–PCR.
†Number positive (apparent prevalence). Numbers and apparent prevalence for VI are after RT-PCR result.
‡Isolates typed by the National Veterinary Services Laboratory. Seven isolates were confirmed as avian influenza but were unable to be subtyped. Included are virus isolates that were RT-PCR negative on the original sample.
§Apparent prevalence not calculated due to the small sample size.
¶Other species sampled that were negative for AI by RT-PCR and VI, number sampled: American coot (Fulica americana), 27; Black-bellied whistling duck (Dendrocygna autumnalis), 9; Canvasback (Aythya valisineria), 3; Common snipe (Gallinago gallinago), 2; Greater white-front goose (Anser albifrons), 3; Hooded merganser (Laphodytes cucullatus), 3; Least grebe (Tachybaptus dominicus), 1; Lesser Scaup (Aythya affinis), 26; Mallard (Anas platyrhynchos), 4; Redhead (Aythya amercana), 3; Ross’s goose (Anser albifrons), 5; Sandhill crane (Grus candensis), 8; and unidentified teal, 1.