- Risk factors associated with the acquisition of extended-spectrum β-lactamase producing Enterobacterales (ESBL-E) during the Klebsiella pneumoniae ST307 outbreak at the Equine Veterinary Teaching Hospital (EVTH) during April – August 2013. The number of horses being compared to among cases and controls as well as their proportion is displayed for each variable studied. Risk factors with a P-value < 0.05 are highlighted