Tuberculosis is currently a leading infectious disease in both human and animal populations across the world. Because it is an older disease, it goes under recognized in all groups – especially wildlife. While it may not generate as much attention as HIV, or Ebola, it can have greater impact on the balance of the environment and our wildlife populations.
We recently chatted with Dr. Michele Miller, the Chief Veterinary Officer and Director of the Center for Conservation Medicine at the Palm Beach Zoo, to get a better understanding of tuberculosis in wildlife populations and its potential impact. [click here for Part 1 of our series]
How did you get involved in the fight to stop tuberculosis in animals?
I have a great deal of interest in infectious diseases and training in immunology. I am the national veterinary advisor for the American Zoo Association for elephants in captivity. Because tuberculosis is a significant concern for our population, we really want to get better diagnostic tests – and not just for our elephants, but for other species as well. That is what keeps me inspired.
How much of an impact will tuberculosis have on wildlife if it goes without prevention or treatment?
Because we are unable to detect infection in animals until very late in the course of the disease, animals may spend years shedding the bacteria, contaminating the environment and infecting other animals. Once this happens it is very difficult to eradicate the disease from population. In closed populations like some of South Africa’s national parks, it’s been predicted that if we do not do something about the disease in lions, then over the course of the next 50 years, there might be as much as a 90 percent decline in the number of lions.
Do you think that this is a priority? Are there enough resources available to combat this problem?
Few resources have been devoted to studying this disease in wildlife. It should be considered a priority disease not only for the species that are affected, but for all the other species that can potentially be affected, including humans. There are so many instances of the spread of infection among species, including badgers in the United Kingdom and brush tailed opossums in New Zealand, which have picked up the disease from cattle. These are all very famous examples of wildlife populations that have been affected by tuberculosis and are being studied. Nevertheless, many, many more species are affected.
How would you go about solving the problem of tuberculosis in wildlife?
Unfortunately, it is very difficult to treat individual animals unless they are in a zoo. We have been trying to develop better diagnostic tests that can be applied to many different species. Certainly, a culture takes a very long time and is difficult to do in some of these animals. So getting rapid tests that can be used in the field by biologists, veterinarians or other researchers working with wildlife, is critical. It is really the key to first identifying the disease and, second, trying to understand the epidemiology of the disease. With more information, we can start to look at ways of managing the infection in a way that can minimize the spread to other populations and, we hope, have less of an impact on the target species.
We are actually working in collaboration with a diagnostic company and wildlife veterinarians in South Africa and Zimbabwe to study this disease and validate some of the blood-based field tests.
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Stay tuned to hear more from Dr. Michele Miller on the state of funding to stop TB in wild animals…