TB or
not TB?
Avian Tuberculosis Is An Ipmortant Part Of Infectious Screening
Recent developments in DNA technology have
created new and exciting diagnostic options in the field of
avian medicine. These advancements have made it possible to
accurately detect harmful infectious agents such as viruses,
bacteria, and parasites from easy to obtain samples such as
swabs, blood or droppings. With the increasing efficiency
and availability of new diagnostic tests, screening all newly
acquired birds is highly recommended to control the spread
of pathogens, and consequently, ensure a healthy environment
for pets and pet owners alike.
Thanks to new DNA based diagnostic procedures,
isolating newly acquired birds for long periods of time prior
to introducing them to a collection is a practice long forgotten.
Infectious screening provides bird owners with the opportunity
to safely and immediately introduce new birds into their collections
without the fear of exposing them to infectious and often
deadly organisms.
Numerous harmful organisms are transmittable
from animals to humans and are occasionally responsible for
causing severe illness and disease. One such infection that
is dangerous to both humans and birds alike is tuberculosis.
Tuberculosis infection characteristically affects the respiratory
system and causes symptoms such as coughing, wheezing, trouble
breathing and other forms of general respiratory distress.
DNA technology has provided new diagnostic options that allow
for accurate detection of tuberculosis, such that early treatment
may be administered.
Avian flu is a chronic and debilitating infection
caused by an acid-fast bacterial rod known as mycobacterium.
Tuberculosis infection in birds is most commonly associated
with two strains of mycobacterium, M. avium, and
M. genovense. Typically, three histological categories
of infection are observed in birds infected by mycobacterium.
The classic form is characterized by the presence of tubercles
or granulomas (walled off areas of infection) throughout many
organs in the body. Clinically, this form affects the bird’s
lungs and is associated with respiratory distress, characteristic
of tuberculosis infection. A second observable form is associated
with lesions in the intestinal tract and is often detected
in amazons, pionus, and Brotogeris parrots. This form of infection
can be particularly hazardous since high numbers of bacteria
are typically shed in the feces creating a hostile environment
ideal for disease transmission. The third and most elusive
form is known as the nontuberculous or atypical form and is
very difficult to recognize. This form commonly occurs in
finches, canaries, and small psittacines. The liver is usually
very enlarged and large numbers of mycobacteria are commonly
detected during cytological and histopathological examination.
Avian tuberculosis is particularly deadly due to the fact
that all birds are susceptible and can potentially transmit
the bacteria to humans. High prevalence of transmission amongst
birds is usually correlated with large collections typical
of zoos or high volume breeding operations. In fact, according
to some publications, tuberculosis infection accounts for
nearly 15 % of all avian deaths in zoological parks containing
mixed species. In most instances, mycobacteria are spread
by food and water contamination by feces.
Previously, diagnosis of tuberculosis in
living birds has been extremely difficult relying on x-rays,
endoscopy, and staining for acid-fast bacteria in the feces,
which is not specific. Fortunately, contemporary advancements
in DNA diagnostics have produced new and superior techniques
that enable accurate and specific pathogenic detection. Recenty,
HealthGene Laboratory has taken diagnosis of Mycobacterium
to the next level through the introduction of a new PCR based
assay that allows for sensitive and timely detection of two
strains of mycobacterium most commonly associated with avian
tuberculosis (M. genovense and M. avium).
HealthGene’s preliminary laboratory results have shown
a 3% positive infection rate from initial samples submitted.
Furthermore, in some cases, independent government laboratories
have confirmed positive results. Tuberculosis screening is
also part of HealthGene’s Health Awareness Program aimed
at promoting a pathogen-free environment for pet owners. Test
requirements are 0.1-0.3 ml of whole blood (EDTA tube) and
a fecal sample. Test code: A118 - Avian Tuberculosis.
