Characteristics of Tuberculosis Tests Performed during Postimport Quarantine of Nonhuman Primates, United States, 2021 to 2024.

Abstract

Screening nonhuman primates (NHPs) for tuberculosis (TB) is important to protect the health of NHP colonies and people who interact with them. Screening is especially important for imported NHPs from countries where TB is prevalent and biosecurity practices may be lax. There are a variety of testing methods available for TB screening and diagnosis in NHPs; all have limitations, and their performance in different settings is incompletely characterized. The US Centers for Disease Control and Prevention (CDC) collects TB testing results as part of its regulatory oversight of NHP importation. We collated the results of tuberculin skin tests (TSTs), interferon-γ release assays (IGRAs), multiplexed fluorometric immunoassay (MFIA), Mycobacterium tuberculosis complex PCR, staining for acid-fast bacilli (AFB), and culture of bacteria from tissues for imported NHPs in CDC-mandated quarantine during fiscal years 2021 to 2024. We used these data to assess test performance and intertest agreement for the different tests used. Among 107 imported NHPs tested, TST and IGRA were the most common antemortem tests performed, but they agreed poorly with each other and with culture. AFB staining and PCR exhibited moderate agreement and high positive predictive values using culture as the gold standard. The most commonly affected tissues were lungs and tracheobronchial lymph nodes, regardless of the Mycobacterium sp. identified. Further research is needed to identify and validate additional methods for TB testing in NHPs, particularly for antemortem screening. Tissue acid-fast staining and PCR exhibited high positive predictive values and could be useful to inform policies and clinical decisions about colony management and occupational health while awaiting culture results.