Pathogenicity of the Canadian Delmarva (DMV/1639) Infectious Bronchitis Virus (IBV) on Female Reproductive Tract of Chickens
Bibliographic record
Abstract
Infectious bronchitis virus (IBV) infection causes significant economic losses to various sectors of the poultry industry worldwide. Over the past few years, the incidence of false layer syndrome in Eastern Canadian layer flocks has been associated with the increased prevalence of the IBV Delmarva (DMV)/1639 strain. In this study, 1-day-old specific-pathogen-free (SPF) hens were infected with the Canadian DMV/1639 strain and observed until 16 weeks of age in order to determine if the IBV DMV/1639 strain is causing false layer syndrome. Early after infection, the virus showed a wide tissue distribution with characteristic gross and histopathological lesions in the respiratory tract and kidney. Around 60-70% of the infected hens demonstrated continuous cloacal viral shedding until the end of the experiment (at 16 weeks) which was associated with high IBV genome loads detected in the cecal tonsils. The experiment confirmed the field observations that the Canadian DMV/1639 strain is highly pathogenic to the female reproductive tract causing marked cystic lesions in the oviduct. Moreover, significant histopathological damage was observed in the ovary. Our study provides a detailed description of the pathological consequences of the IBV DMV/1639 strain circulating in an important poultry production sector.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".