Detection of porcine reproductive and respiratory syndrome virus in semen and serum of boars during the first six days after inoculation
Bibliographic record
Abstract
Objectives: To determine, during the first 6 days post inoculation, when porcine reproductive and respiratory syndrome virus (PRRSV) can be detected in serum or semen by polymerase chain reaction (PCR); the impact of pooling on detection of PRRSV by PCR; and the possible association between rectal temperature and detection of PRRSV in serum by PCR. Materials and methods: Forty mature boars (four groups of 10) were inoculated intranasally with PRRSV variant MN 30-100. Serum and semen samples were collected on a rotating basis from one group every 12 hours for 6 days and tested for PRRSV by PCR. Rectal temperatures were recorded for all 40 boars at 12-hour intervals. Results: Serum samples became PCR-positive before semen samples. During the first 6 days after inoculation, serum was PRRSV-positive in 36 of 40 boars, and semen was PRRSV-positive in four of 40 boars. Median time to detection was 36 and 72 hours for nested PCR and Taqman PCR, respectively. Results were inconsistent when a positive semen sample was pooled with negative semen. Elevated rectal temperature was not associated with PCR-positive serum or semen results. Implications: Under the conditions of this study, PCR is more sensitive and detects PRRSV-infected boars earlier in serum than in semen. Pooling of positive semen samples provides variable PCR results. Rectal temperatures are not correlated with PCR-positive results. Sampling techniques are needed to more easily obtain serum samples for PCR from boars once or twice weekly at the time of semen collection.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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".