Volume 15, Number 12—December 2009
Dispatch
Transplacental Transmission of Bluetongue Virus 8 in Cattle, UK
Table
Bluetongue virus real-time reverse transcription–PCR results from follow-up sampling of calves with initial positive results, United Kingdom, December 20, 2007, to March 15, 2008*
Calf no. | First BTV result, age, d (Ct) | Retest results, age, d (Ct) |
Age, d, when PCR negative | Estimated gestation, d† | ||||
---|---|---|---|---|---|---|---|---|
Retest 1 | Retest 2 | Retest 3 | Retest 4 | Retest 5 | ||||
1 | 15 (25) | 28 (26) | 44 (26) | 58 (28.5) | 72 (32.5) | 91 (neg) | 91 | 82–219 |
3 | 38 (31) | 47 (32) | 61 (35.5) | 81 (neg) | NT | NT | 81 | 106–243 |
10 | 79 (32) | 106 (33.5) | 120 (34) | 137 (neg) | 158 (neg) | NT | 137 | 140–197 |
12 | 81 (28) | 108 (30) | 122 (31) | 139 (34) | 160 (neg) | NT | 160 | 142–199 |
13 | 4 (33) | 31 (36.5) | 45 (neg) | 62 (neg) | 83 (neg) | NT | 45 | 65–122 |
14 | 28 (26) | 48 (29) | 55 (32) | 69 (neg) | 86 (neg) | 107 (neg) | 69 | 154–209 |
15 | 70 (32) | 97 (neg) | 111 (neg) | 128 neg) | 149 (neg) | NT | 97 | 196–251 |
20 | 17 (31) | 44 (32.5) | 58 (33.5) | 75 (neg) | 96 (neg | NT | 75 | 78–128 |
25 | 27 (29.5) | 41 (29) | 55 (30.5) | 69 (36) | NT | NT | >69‡ | 145–202 |
28 | 1 (23) | 26 (25) | 35 (26) | NT | NT | >35‡ | 101–181 | |
29 | 1 (27) | 12 (27.5) | Calf died | 45–182 | ||||
41 | 47 (28) | 61 (29.5) | NT | NT | NT | NT | >61‡ | 79–126 |
45 | 22 (27) | 40 (30.5) | 61 (34) | NT | NT | NT | >61‡ | 52–130 |
47 | 25 (26.5) | 39 (29) | 66 (38) | NT | NT | NT | >66‡ | 52–189 |
49 (twin with 50) | 46 (29) | 60 (36) | 87 (neg) | NT | NT | NT | 87 | 73–136 |
50 (twin with 49) | 46 (29) | 60 (36.5) | 87 (neg) | NT | NT | NT | 87 | 73–136 |
55 | 21 (25.5) | 48 (31.5) | NT | NT | NT | >48‡ | 34–172 |
*BTV, bluetongue virus; Ct, cycle threshold; neg, negative; NT, not tested.
†Estimated stage of gestation at which transplacental infection may have occurred
‡These calves could not be followed up for farm management reasons or because the project had ended.