Zero inflated count regression for one year prediction of bovine trichomonosis in a compulsory control plan in La Pampa, Argentine.

Abstract

Data from 533 farms with bovine trichomonosis were investigated through hurdle and zero inflated models to quantify the burden of recurrent bovine trichomonosis. The probability of having a positive result in the following year for those farms with a previous positive test was 10.7%. Keeping or buying infected animals increased the odds of having positive results by 2.8 (95% CI = 1.41-5.56). The number first cases significantly decreased the chances of being no-at-risk (OR = 0.64; 95% CI = 0.47-0.89) and the chances of being positive in the following season (OR = 1.09; 95% CI = 1.01-1.18). The number of animals tested significantly increased the chances of being positive in the next season (OR = 1.02; 95% CI = 1.01-1.03). Both the number of positives and the number of animals tested suggest a significant proportion of new cases detected were false positives. These epidemiologic indicators are likely important determinants in the selection of farms requiring more intensive control measures and farms where testing results should be confirmed.