Simple and highly sensitive methods to monitor infection or exposure to Mycobacterium tuberculosis in nonhuman primates (NHPs) are unavailable except for the tedious tuberculin skin test (TST). The study focused on establishing quantitative real-time PCR (qPCR) as the method for direct and non-invasive detection of M. tuberculosis in peripheral blood of NHPs in vitro. We investigated the rates of M. tuberculosis in three different NHP colonies. All the TST-positive samples were confirmed as infected except for three samples with CT values above 40, which were deemed negative. Four TST-negative samples were shown to be positive using CT. In the three different colonies, the detection rates of M. tuberculosis in the peripheral blood were 10, 19.5 and 24%, respectively. The results suggested that qPCR was an auxiliary method with speed, accuracy and simplicity, which facilitate the screening and breeding of specific pathogen-free (SPF) or higher grade simians, and for disease surveillance programs.

Key words: Mycobacterium tuberculosis, NHPs, Peripheral blood, qPCR