Table 1.
History of herd and timeline of the outbreak investigation.
| Action | Date | Number of animals | |
|---|---|---|---|
| Elk | Fallow deer | ||
| Original herd size | 2008 | 60 | 50 |
| SCT performed | March 2008 | 50 (all negative) | Not tested |
| Index case detected | January 30, 2009 | 1 | 0 |
| SCT performeda | February/March 2009 | 42/59 tested (3 true positive, 25/39 false negative*) | Not tested |
| Postmortem examinationsb | June 2009 | 52 | 48 |
| Serum collected | June 2009 | 34/52 examined | 32/48 examined |
| Apparent prevalencec | June 2009 | 75% (40/53 TB positive) | 71% (34/48 TB positive) |
aOnly 42/59 elk and none of the fallow deer were tested by SCT primarily due to animal handling and management issues. All of the elk that were tested by SCT were examined postmortem.
bHerd depopulation completed; however, not all of the carcasses were examined.
cThe apparent prevalence includes the index case and is based upon the number of animals with mycobacteriosis compatible gross and microscopic lesions and/or M. bovis isolated from tissues.
*Necropsies were performed 3 months after SCT; thus, values may underestimate the true false negative rate.