An Overview of the National Zoological Tuberculosis Monitoring System for Hoofstock
Tuberculosis, particularly Mycobacterium bovis and M. tuberculosis, has always been considered an important health issue in zoological collections. In 1996, upon the diagnosis of active Mycobacterium tuberculosis infections in several zoo elephants,1,2 the Tuberculosis Committee of the United States Animal Health Association recommended “the USDA...pursue the formation of an inter-industry working group to address the issues of tuberculosis in exotic animal collections.” Thus, the National Tuberculosis Working Group for Zoo and Wildlife Species was formed, consisting of members representing the zoological, wildlife, regulatory, and diagnostic fields. The mission of this group has been “to control and ultimately eradicate tuberculosis (M. tuberculosis complex) and control other mycobacterial diseases in zoo and wildlife species.”
The Working Group has proceeded along two parallel paths to date; one focuses largely on elephants, the other on ungulates. In 1998, the group developed the Guidelines for the Control of Tuberculosis in Elephants; these were updated in 2001 to deal with treatment of isoniazid resistant strains of M tuberculosis recently isolated from elephants. In 2000, Ziccardi et al. conducted a survey of 139 AZA affiliated institutions (92.7% of those holding ungulates) to determine the level of tuberculosis diagnosed in several categories (bovids, camelids, cervids, elephants, giraffes, hippopotamus, rhinoceros, ruminants, swine and tapir).3 These data were used to finalize the guidelines for ungulate species in zoo environments.
Currently, the Working Group is finalizing the “Tuberculosis Surveillance Plan for Nondomestic Hoofstock.” The purpose of this surveillance plan is to:
- Establish a standard for intradermal tuberculin testing of hoofstock species (other than cattle, bison, and deer) housed in zoological collections.
- Collect prospective data on intradermal tuberculin testing and other diagnostic tests in order to determine sensitivity and specificity; establish guidelines for the interpretation of results and for the course of action in the interim period before the skin test is validated or other methods of diagnosis are identified.
- Accurately estimate the true prevalence and incidence of tuberculosis in zoological collections and assess the risk of transmission to program species.
- Provide guidance for state and zoo veterinarians, curators, keepers, and other staff exposed.
- Prevent the transmission of TB within and between zoological collections.
Currently, Lincoln Park Zoo has developed and piloted a mechanism aimed at collecting the information required to accomplish the goals stated above. The requirements of the working group for this system were that it:
- Should be web-based, although it should also be available in paper format where needed.
- Should be extremely user friendly, lending itself to rapid, no hassle data entry,
- Provide assurance of confidentiality for both users and their data; each user will need to register and be given permission to have a user name and password.
- Should integrate with other data/record keeping systems such as the proposed ZIMS record keeping system.
- Provide real-time summaries of data entered; access to this information will be limited to those users entering data and all information will be coded to protect institutional confidentiality.
- Should provide an easy mechanism for sharing data with collaborators approved by the working group, while maintaining confidentiality.
Lincoln Park Zoo’s Davee Center for Veterinary Epidemiology has created a website to house this surveillance and monitoring system and others like it. In the future, we plan to assess the viability of adding primates and expanding the elephant component of the TB database, as well as adding an additional West Nile virus database. We hope that this site will provide a useful tool for the collection of long-term monitoring of many diseases of importance to the captive and free-ranging wildlife communities.
1. Michalak K, Austin CA, Diesel S, Bacon JM, Zimmerman P, Maslow JN. Mycobacterium tuberculosis infection as a zoonotic disease: transmission between humans and elephants. Emerging Infectious Diseases. 1998;4(2):283–287.
2. Mikota SK, Peddie L, Peddie J, Isaza R, Dunker F, West G, et al. Epidemiology and diagnosis of Mycobacterium tuberculosis in captive Asian elephants (Elephas maximus). Journal of Zoo and Wildlife Medicine. 2001;32(1):1–16.
3. Ziccardi S, Mikota SK, Barbiers RB, Norton TM, Robbins PK, the National Tuberculosis Working Group for Zoo and Wildlife Species. Tuberculosis in zoo ungulates: survey results and surveillance plan. In: Proceedings from the American Association of Zoo Veterinarians. 2000:438–441.