Mortality rate and movements of brushtail possums with clinical tuberculosis ( <i>Mycobacterium bovis</i> infection)

Abstract

This study estimated the mortality rate during the clinical stages of Tb and, as such, did not represent a true estimate of the disease-induced mortality rate (alpha) used in most epidemiological models of possums and Tb. However, the lower estimate of the additional mortality rate due to clinical disease could be considered an approximation to alpha. The movement patterns of clinically tuberculous possums were, overall, not substantially different from non-diseased possums. The occurrence of long-distance movements by tuberculous possums sometimes coincided with the advanced stage of clinical disease. However, the majority of tuberculous possums died within their established activity area. Long-distance movements by resident possums during the terminal stages of disease represent a direct risk for transmission of Tb to livestock on farms within approximately 1 km of infected possum populations.