Volume 30, Number 12—December 2024
Dispatch
Transmission of Swine Influenza A Viruses along Pig Value Chains, Cambodia, 2020–2022
Arata Hidano, Dina Koeut, Hannah Holt, William T.M. Leung, Sokhom Krean, Vutha Chhim, Bunnary Seng, Sovanncheypo Chao, Wong Foong Ying, Pov Son, Sina Vor, Sokchea Huy, Ty Chhay, Sothyra Tum, San Sorn, Monidarin Chou, Yvonne C.F. Su, Gavin J.D. Smith, and James W. Rudge
Table
Batch- and slaughterhouse-level results from pig sampling, stratified by slaughterhouse province in a study of transmission of swine influenza A viruses along pig value chains, Cambodia, 2020–2022*
| Characteristics | Overall | Slaughtherhouse province |
|||
|---|---|---|---|---|---|
| Kampong Speu | Kandal | Takeo | Phnom Penh | ||
| Slaughterhouses | 18 | 5 | 6 | 4 | 3 |
| Batches | 616 | 200 | 136 | 175 | 105 |
| From commercial farms | 397 (64.4) | 137 (68.5) | 97 (71.3) | 94 (53.7) | 71 (67.6) |
| PCR-positive | 37 (6.0) | 1 (0.5) | 15 (11.0) | 12 (6.9) | 9 (8.6) |
| ELISA-positive | 355 (59.1) | 127 (63.5) | 75 (55.1) | 95 (54.3) | 58 (55.2) |
| Batch size, median (range) | 6 (1–120) | 5 (1–110) | 5 (1–32) | 6 (1–31) | 20 (2–120) |
| Samples per batch, median (range) | 6 (1–16) | 5 (1–16) | 5 (1–15) | 6 (1–13) | 12 (2–16) |
| Within-batch prevalence, median (range)† | 20 (6.7–100) | 50 | 33.3 (6.7–100) | 14.3 (10–66.7) | 12.5 (7.1–55.6) |
| Within-batch seroprevalence, median (range)‡ | 50 (6.7–100) | 50 (6.7–100) | 58.3 (9.1–100) | 50 (10–100) | 50 (6.7–100) |
| Male percentage per batch, median (range) | 50 (0–100) | 42.9 (0–100) | 50 (0–100) | 50 (20–100) | 50 (0–100) |
| Finisher percentage per batch, median (range) |
100 (0–100) |
100 (0–100) |
100 (100–100) |
100 (0–100) |
100 (100–100) |
| Batches by cleaning frequency of slaughterhouse | |||||
| Daily | 536 (87.0) | 176 (88) | 111 (84.1) | 175 (100) | 74 (70.5) |
| Weekly | 45 (7.3) | 24 (12) | 21 (15.4) | 0 | 0 |
| Monthly |
31 (5.0) |
0 |
0 |
0 |
31 (29.5) |
| Transport duration, h, median (range) |
0.8 (0.1–10.1) |
0.5 (0.2–7.9) |
1.5 (0.5–9.9) |
0.3 (0.1–10.0) |
2.1 (0.9–10.1) |
| Duration at slaughterhouse, h, median (range) |
12 (2–144) |
10 (2–48) |
12 (5–48) |
12 (5–144) |
8 (5–20) |
| Batches by location of originating farm | |||||
| Kampong Speu Province | 329 (53.4) | 177 (88.5) | 69 (52.3%) | 39 (22.3) | 44 (41.9) |
| Takeo Province | 133 (21.6) | 2 (1.0) | 0 (0) | 125 (71.4) | 6 (5.7) |
| Kampong Chhnang Province | 42 (6.8) | 14 (7.0) | 0 (0) | 0 (0) | 28 (26.7) |
| Cambodia, other province | 53 (8.6) | 6 (3.0) | 36 (27.3) | 3 (1.7) | 4 (3.8) |
| Imported from Thailand | 59 (9.6) | 1 (0.5) | 27 (20.5) | 8 (4.6) | 23 (21.9) |
*Values are no. (%) except as indicated. †PCR confirmed. Within-batch prevalence and seroprevalence were calculated among positive batches (i.e., with >1 positive pig). Range is not provided for Kampong Speu for within-batch prevalence because only a single batch tested PCR-positive. ‡ELISA confirmed.
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Page updated: November 26, 2024
Page reviewed: November 26, 2024
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