Tuberculosis in a Ruffed Lemur
Tuberculosis infection in a Ruffed Lemur (Lemur variegates variegates)
E. P. Lane, I. W. Espie
A 10-year-old male Ruffed Lemur died suddenly over night. Necropsy examination revealed a large blood clot in the abdomen, due to bleeding from a soft mass at the root of the mesentery (the membrane that holds the intestines in place). Microscopic examination showed that the mass was a severely inflamed lymph node. Tiny foci of inflammation also occurred throughout the mesentery. Special stains showed the presence of small numbers of acid-fast organisms in macrophages in the lymph node and mesentery. Culture results for Mycobacterium tuberculosis are pending.
Although tuberculosis organisms are not the only ones to stain acid fast, the features of this case are strongly suggestive of tuberculosis. The infection is likely to have gained entry into the intestines, and moved from there to the lymph node, where it caused severe inflammation. We speculate that the Lemur may have been involved in a minor traumatic incident, perhaps a fall, and the sudden increase in abdominal pressure resulted in rupture of the severely inflamed lymph node and bleeding into the abdomen. Death was due to acute drop in blood pressure.
Typically Lemurs and other prosimians have a very low incidence of tuberculosis, unlike other non-human primates. This case is very therefore very important, in confirming that prosimians are susceptible to tuberculosis. Therefore, like with other primates, contact with humans and preventing zoo visitors from feeding Lemurs is essential. Previous research at the National Zoo has indicated that most, if not all, zoo animals that develop tuberculosis are infected by members of the public.
H F K A Huchzermeyer, G K Bruckner, A van Heerden, H H Kleeberg, I B J van Rensburg, P Koen and R K Loveday Tuberculosis in Infectious Diseases of Livestock Eds. J A W Coetzer, G R Thomson, R C Tustin and N P J Kriek.Oxford University Press, 1994 p14231
R Isaza Tuberculosis in All Taxa. In Zoo and Wildlife Medicine (5th Edition). M E Fowler and R E Miller. Elsevier Science, 2003 pp689-691
R E Junge Prosimians. In Zoo and Wildlife Medicine (5th Edition). M E Fowler and R E Miller. Elsevier Science, 2003 p337
A L Michel, L Venter, I W Espie, M. L. Coetzee Mycobacterium tuberculosis infections in 8 species at the National Zoological Gardens of South Africa, 1991-2001. Journal of Zoo and Wildlife Medicine 34(4):364-370