Lung lavage as new test method improves tuberculosis diagnosis in rhinoceros

Date:  December 12, 2018

Source:  Forschungsverbund Berlin

Diseases and tuberculosis in particular can pose considerable challenges for wildlife. In order to avoid epidemics within populations or to treat individual animals belonging to highly endangered species, fast and reliable tests are paramount. However present tuberculosis testing in rhinos relies on skin tests developed in the 1960s and designed for cattle bearing high risk of false diagnosis in rhinos. To improve diagnostic standards an international team of scientists led by institutes in Berlin and Jena, Germany, performed repeated lung lavage as a new approach for tuberculosis diagnosis in rhinoceros. Subsequent genetic tests reliably identified mycobacteria in the animals' respiratory fluids -- with minimal stress and risk for the rhinos. The study has been published in the journal PLOS ONE.

Conventional immunological tests for tuberculosis in rhinoceros are substantially insecure and bear high risk of false negative or false positive diagnosis with sometimes fatal consequences for the animal. At present only examinations carried out on deceased animals allow a reliable tuberculosis diagnosis. This situation has been the starting point for the team of scientists at the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) and the Friedrich-Loeffler-Institut (Federal Research Agency for Animal Health, FLI) to genetically analyse lung lavage fluids for mycobacteria as a new approach for tuberculosis diagnosis in these two-tonne animals. This required a short standing sedation, endoscopic exploration of the rhinoceros lung and collection of respiratory fluids. The collected fluids were tested for the presence of genetic material from mycobacteria in general and tuberculosis pathogens in particular. In parallel, the samples were cultured under special conditions to foster the growth of viable mycobacteria.

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