t hat may be fou nd on zoo g rou nds becau se t hey represent t he t h reat of disease
i nt roduct ion. Because of t hei r com m it ment to con ser vat ion efforts, zoos mai n-
tain serum and tissue banks that can prove critical to disease investigations.
Necropsies are performed on all collection animals in accredited institutions.
Most important of all, zoo surveillance is sustainable as disease surveillance
is part of their everyday activities. Recent examples of the value of zoos in
public health surveillance include the discovery of the first plague outbreak
since 1968 in metropolitan Denver when the zoo submitted five squirrels and
one rabbit for diagnostic evaluation in May 2007. Another example is the dis-
covery that felids are susceptible to H5N1 influenza, known only because the
zoo in Thailand performed necropsies and submitted tissues for diagnosis on
dead tigers and leopards (Keawcharoen et al. 2004).
In this chapter, we describe a number of zoo initiatives that have proved to
be beneficial to public health efforts. These programs leverage the activities
routinely done in zoos, and, in doing so, they close at least one of the many
surveillance gaps between human, agricultural, and nonagricultural species.
There are too many proverbial balls in the air to have any level of comfort
that the next emerging zoonotic threat will not be missed as has been the
case in the past. It makes sense for public health entities to partner with the
zoo community. As Laura Kahn stated in “Animals: The World's Best (and
Cheapest) Biosensors” (Kahn 2007), “those of us who are truly concerned
about early identification of emerging infectious diseases and bioterrorism
should promote and encourage funding of programs such as the national
zoo surveillance network and other programs that focus on the surveillance
of nonagricultural species. Time and time again, they've proven to be the
best and cheapest environmental biosensors around.”
5.2 Association of Zoos and Aquariums (AZA)
Ungulate Tuberculosis Monitoring Program
5.2.1 infectious agent
Tuberculosis (TB) is a chronic disease of mammals caused by bacteria of the
genus Mycobacterium . The organisms can be found worldwide, generally liv-
ing in water and food sources. There are many species of Mycobacterium ,
each with its own preferred hosts. For example, the reservoirs for M. bovis
include cattle, dogs, and pigs, while M. avium is found most frequently in
birds, pigs, and sheep. Humans are most often infected with M. tuberculosis ,
though this species can also be passed to nonhuman primates, cattle, dogs,
pigs, and psittacine birds.
Transmission occurs through aerosol droplets or contact with infected
animals or contaminated surfaces. TB can also be transmitted through