Tuberculosis in free ranging African elephants (Loxodonta africana) in Tanzania
To study tuberculosis in African elephants in Tanzania
Little is known about the tuberculosis (TB) status in free ranging African elephants, Loxodonta africana, in Tanzania. As the country faces a rapid growing human-wildlife-interface, the transmission of diseases is one of the major concerns for sustainable wildlife conservation strategies. In one study at Ruaha National Park 37% (7/19) of wild animals and 14% (17/124) of the sampled livestock had growth of bovine tuberculosis on culture. Elephants usually move long distances within and outside protected areas, which comes along with increased risk for infections spreading from human beings and their livestock to elephants and vice-versa. Our experience with zoo elephants indicates a high susceptibility for tuberculosis infections in the African (Loxodonta africana) as well as the Asian Elephant (Elephas maximus). Recently a new rapid test (RT) “ElephantTB STAT-PAK Assay” (Chembio Diagnostic, Inc., USA) has been established on the market. The classic method of culturing samples takes a long time and is difficult to handle under extreme tropical conditions. The new rapid test kit could be an alternative for field research. The detection time is now decreased from weeks in culture techniques to around 20 minutes in the rapid test. Elephants in Tanzania get immobilized on several occasions, example given for snare-removal or radio-collaring. As these activities are mainly coordinated by Sokoine University of Agriculture (SUA), we want to establish a new project for a German-Tanzanian cooperation. Blood as well as trunk-wash samples (control) can easily be obtained from immobilized elephants in the field. Ideally other TB test systems, e.g. the MAPIA test shall be used for additional validation purposes. Our goal is to establish a modern and rapid technique for tuberculosis screening in elephants under field conditions and finally to gain first data about the tuberculosis status in the Tanzanian elephant population. Local researchers at SUA will additionally gain knowledge of a technique that helps in controlling diseases in protected and surrounding areas much more efficient than traditional diagnostic procedures can do. The project provides research opportunities for native vet students. At least one Tanzanian MSc/ PhD student will be elected for the ongoing field work.
Specific Conservation Goals:
The implementation of a rapid tests for tuberculosis field testing in elephants further more contribute to a second SUA project, where the prevalence of tuberculosis in man, domestic livestock and wildlife is investigated in areas with close human-wildlife interface at Mikumi National Park.
Methods/Plan of Action:
During a short field trip in summer/ autumn 2008, Dr. Arne Lawrenz and Sascha Knauf will train the local veterinary staff to collect and conserve samples for TB testing. Additionally the RT “ElephantTB STAT-PAK” (Chembio Diagnostic, Inc., USA) and if possible the multiprint immunoassay (MAPIA) shall be implemented at SUA, as this tests have never been used before in Tanzania.
During routine immobilization of elephants, blood samples are taken from the ear-veins or the Vena saphena lateralis. Blood components are separated by sedimentation over time. Obtained serum, respectively plasma, will be divided into a representative numbers of aliquots and a RT will be run directly at the field side. Remaining aliquots of serum or plasma get frozen in liquid nitrogen and stored for further research activities at SUA laboratories. If it is possible to establish the MAPIA test, as well, this test shall be performed at SUA laboratories.
Trunk-wash samples are gold-standard in tuberculosis diagnostic in elephants. Therefore 60 ml of sterile saline solution are instilled into the trunk. After elevating and shaking the trunk the saline solution is recollected with a zipper-lock plastic bag and divided into a representative number of aliquots thereafter. Samples will be cultured at SUA for potentially Mycobacteria growth. The results obtained from the trunk wash and serology get correlated with the results of the field RT results.
Anticipated Outcome/Impact of Project:
Due to the high prevalence of TB in Tanzania and the growing impact of human wildlife interactions it is likely that even elephants, as a species that is highly susceptible for tuberculosis infections, are highly influenced by this emerging zoonotic disease. Sustainable wildlife conservation on Africa’s elephant population needs a proper disease monitoring. Especially in diseases with a high mortality and a subtle chronic history it is essentially important to indentify positive reactants as early as possible. The data obtained from this first preliminary survey are important for the planning of future research activities in TB as a emerging zoonotic disease.
How the Project’s Outcome will be Evaluated:
Currently there are no data available about the TB status of Tanzania’s elephant population. Therefore the scientific output of this first study will influence future activities in this area. The outcome will contribute to the health-management of locals who live in close contact with wildlife and domestic livestock. The evaluation and introduction of a TB rapid test will fasten the momentary diagnostic procedure and gives support to native scientists who help in controlling wildlife diseases.
WAZA Conservation Project 08009 is supported by the Wuppertal Zoo (Germany), Opel-Zoo in Kronberg (Germany), Pittsburgh Zoo Conservation Fund (USA) and Chembio Diagnostic Systems (USA), in collaboration with the Sokoine University of Agriculture (Tanzania).
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