Comparative studies of histopathologic lesions from 23 purified protein derivative (PPD) positive cattle, 21 slaughter cattle found with tuberculosis, and 11 tuberculosis-positive elk (Cervus elaphus) were performed. PPD positive cattle did not show specific histopathologic lesions in all 23 heads that were no visible lesion reactor. Slaughter cattle found with tuberculosis revealed microscopically classical granulomatous lesion (tubercle) with central caseous necrosis surrounded by mantle of epithelioid cells and Langhan's giant cells capsuled by connective tissue in lung. Elk was noted with some different lesion patterns with classical granulomatous lesion and suppurative abscesses that was composed of fibrin, degenerated cells without having connective tissue. In addition, many Langhan's giant cells infiltration in alveoli at peripheral lesion were observed in some cases of classical granulomatous lesion and suppurative abscesses.

The present study describes an investigation on an epidemic of Tuberculosis (TB) which has been occurred among dairy cattle farms in Jeongeup, Jeollabuk-do since 2007. The investigation was performed in three ways as follows: 1. Collecting information about bovine TB outbreaks using investigation reports, an on-the-spot and tracing-back investigations; 2. Analyzing the outbreak pattern; 3. Establishing hypothesis and performing statistical analysis on potential risk factors. In the early 2000s, TB outbreaks were sporadically reported in beef cattle, and only a small number (1~2) of reactors was confirmed in each of outbreak farms. The number of TB outbreaks has been suddenly increased from 2007, mainly in dairy cattle farms. And these outbreaks were temporarily clustered during the period, from March 2007 to April 2009 (relative risk, RR=13.7, p less than 0.001). And two spatial clusters of which radiuses were 0.3 km (RR=6.9, p less than 0.001) and 0.9 km (RR=3.6, p less than 0.01). The analysis to find risk factors was performed on 99 dairy farms (21 outbreaks), which are located in the most seriously affected village during 2007-2009. Middleman (odds ratio, OR=47.4, p less than 0.05) and raw milk collecting system (OR=6.9, p less than 0.05) were recognized as with the highest association. Considering the fact that all the outbreak farms except one had their own manure composting tank, it might be that the manure containing pathogen was leaked from tank and transmitted to other farms by fomites such as middleman or raw milk collecting system.