Investigation on an epidemic of tuberculosis in dairy cattle farms In Jeongeup, Korea

Yoon, Hachung; Moon, Oun-Kyong; Kim, Youn-Ju; Cho, Bum-Joon; Lee, Soo-Doo; Lee, Jeong-Won; Lee, Sang-Jin

Korean Journal of Veterinary Research 2009;49(4):309-317.

Hachung Yoon¹, Oun-Kyong Moon¹, Youn-Ju Kim¹, Bum-Joon Cho², Soo-Doo Lee¹, Jeong-Won Lee², Sang-Jin Lee¹

¹Veterinary Epidemiology Division, National Veterinary Research and Quarantine Service
²Jeongeup Branch, Jeonbuk Institute of Livestock & Veterinary Research

전북 정읍지역 젖소농장 결핵병 집단 발생에 대한 역학조사

윤하정¹, 문운경¹, 김연주¹, 조범준², 이수두¹, 이정원², 이상진¹

¹국립수의과학검역원 역학조사과
²전라북도축산위생연구소 정읍지소

Abstract

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 ($1{sim}2$) 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 < 0.001). And two spatial clusters of which radiuses were 0.3 km (RR = 6.9, p < 0.001) and 0.9 km (RR = 3.6, p < 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 < 0.05) and raw milk collecting system (OR = 6.9, p < 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.

Key Words: cattle, dairy, epidemic, investigation, tuberculosis