Abstract

Due to the insidious nature, severity and zoonotic potential, Mycobacteria tuberculosis complex (MTB) is uniquely difficult to diagnose in great apes and especially in orangutans. While there are numerous detailed plans and guidelines to combat and manage tuberculosis in captive non-human primates, these are often poorly adapted to field or in-situ scenarios. Due to the poor performance of the various unspecific diagnostic tests (e.g., clinical examination, chest x-rays and blood work) and inadequate and non-validated sensitivity and specificity of indirect and direct tests (e.g., inter-alia: comparative skin tests, interferon-gamma release tests, Ziehl-Nielsen staining) the clinician and manager is necessarily faced with a confusing array of results. We demonstrate in a colony of orangutans in East Kalimantan how the attempt to adhere to complex guidelines in a diagnostic-training-constrained environment is inherently rife with uncertainties. Integrating risk analysis and defining acceptable risk from the onset appears key to moving forwards in addressing this complex multi-faceted problem. When knowledge is uncertain and predictive values are weak, this is often used as an argument to obstruct problem transformation and resolution. We show that finding a transparent forward-thinking approach in dealing with uncertainties is the key to addressing complex problems such as TB management in orangutans.