Factors Affecting Herd Status for Bovine Tuberculosis in Dairy Cattle in Northern Thailand

Abstract EN

The objective of this case-control study was to identify farm-level risk factors associated with bovine tuberculosis (bTB) in dairy cows in northern Thailand.

Spatial analysis was performed to identify geographical clustering of case-farms located in Chiang Mai and Chiang Rai provinces in northern Thailand.

To identify management factors affecting bTB status, a matched case-control study was conducted with 20 case-farms and 38 control-farms.

Case-farms were dairy farms with at least single intradermal tuberculin test- (SIT-) reactor(s) in the farms during 2011 to 2015.

Control-farms were dairy farms with no SIT-reactors in the same period and located within 5 km from case-farms.

Questionnaires were administered for data collection with questions based on epidemiological plausibility and characteristics of the local livestock industry.

Data were analyzed using multiple logistic regressions.

A significant geographic cluster was identified only in Chiang Mai province (p<0.05).

The risk factor associated with presence of SIT-reactors in dairy herds located in this region was purchasing dairy cows from dealers (OR = 5.85, 95% CI = 1.66–20.58, and p=0.006).

From this study, it was concluded that geographic clustering was identified for dairy farms with SIT-reactors in these provinces, and the cattle movements through cattle dealers increased the risks for SIT-reactor farm status.