Bovine Tuberculosis Mycobacterium bovis (Bovine Tuberculosis) (or cattle
Tuberculosis) was first discovered by Columella (Louis Junius Moderatus
Columella) which was born in Cadiz, Spain and resided in Northern Italy when he
discovered the bovine Tuberculosis in the year 14 A D. In 1882 Robert Koch
discovered that the connection between human and animal Tuberculosis actually
were established. When Koch realized that children were becoming infected from
contaminated cow’s milk most nations brought out legal instruments designed to
remove chronically infected animals and take a look at the public health aspect
of the problem. The Disease Mycobacterium bovis is the bacterium that causes
bovine Tuberculosis. It manifests itself in livestock (especially in cattle and
hogs) and it has also affected wild life such as White Tailed Deer, Bear,
Coyotes, Raccoons, and Bobcat in the northeastern part of the Lower Peninsula of
Michigan. From 1995 to 1999 17,721 deer from six counties (Alpena, Montmorency,
Oscoda, Alcona, Presque Ile, and Otsego) in Michigan were taken and examined and
to date only 228 deer, 1 bear, 5 coyotes, 2 raccoons, and 1 bobcat have tested
positive for bovine Tuberculosis. In the same area there was also 3 herds of
cattle infected with the disease. This disease is also known all over the
country and the world from Australia to New Zealand to the United Kingdom. The
most likely way to spread the disease in the wild is the bobcat, coyotes,
raccoons, and bear eating the lungs and lymph nodes of infected animals. There
are three main types of bovine Tuberculosis: human (Mycobacterium
Tuberculosis)which can affect humans and can be transmitted to dogs, cats,
cattle, hogs, goats, sheep, and most any other mammal on earth, bovine
(Mycobacterium bovis) which affects animals and can be transmitted to humans
(but it is very rare that this may happen), avian (Mycobacterium avian complex)
which primarily effect only birds but in some cases there has been some cases in
which cattle and hogs have been infected with the avian Tuberculosis. The
two-mammalian types are more closely related to each other then the avian type.
The disease’s presence in humans has been reduced as a result in the
eradication program, advances in sanitation and hygiene, the discovery of
effective drugs, and pasteurization of milk. There is another minor type of
bovine Tuberculosis, which is as microti (Mycobacterium Microti) which affects
rodents. Mycobacterium Tuberculosis is the most host specific of the three major
types of Tuberculosis, rarely being transmitted to other birds (Mycobacterium
avian), or mammals (Mycobacterium bovis). Bovine Tuberculosis is the most
infectious type of Tuberculosis it infects most warm-blooded animals to include
humans. Condition Bovine Tuberculosis can only live for only a few weeks out
side of the host’s body because it can not handle the exposure of the heat,
direct sunlight, or extremely dry conditions. Bovine Tuberculosis will survive
longer under cool to cold, moist, and dark conditions. The only place the
Mycobacterium will grow (outside of the host) is on a culture plate, where the
bacteria will multiply at a very slow rate of about every 20 hours or so. As
time goes on, bovine Tuberculosis is a disease that take many months or may take
many years to develop or may lie dormant in the host’s body for a lifetime. If
the disease does not become dormant, in wildlife and in livestock it will leave
multiple tan or yellow lumps on the rib cage or yellow lesions on the lungs
about the size of a pea. Transmission Bovine Tuberculosis is a chronic, highly
contagious and infectious disease caused by several bacteria of the
Mycobacterium family (tubercles) which it first affects the respiratory system
and the lymph nodes and may be found in any organ or body cavity. There are
several different ways for animals to contract the disease; one is airborne
exposure from coughing and sneezing, (which is the most frequent way to contract
the disease) which the risk is much higher in enclosed areas, such as barns.
Another way to be infected is the consumption of contaminated food, water, or
milk, from infected animals rubbing on a post or wire and another animal rubs
against the same area, also using infected cattle trailers or transport
vehicles, and avoid interaction and contact with other herds. Eradication
Program The most effective way to handle the problem of bovine Tuberculosis in
humans is to eradicate it in livestock. The eradication program began in 1917,
the cooperative state-federal Tuberculosis eradication program, which was
administered by the U.S. Department of Agriculture (USDA) Animal and Plant
Health Inspection Service (APHIS). All cattle herds were tested, and all of the
cattle that tested positive for bovine Tuberculosis were sent to the
slaughterhouse. After the animals were slaughtered the premises were cleaned and
disinfected after the animals were removed. As a result of the eradication
program, the rate of infected cattle were reduced by approximately 5% to
currently less than 0.02%. The human Tuberculosis also was reduced
significantly. The recent surge of human Tuberculosis is due M. Tuberculosis.
Today, there is a very low rate of bovine Tuberculosis cases in humans. State or
Federal meat inspectors check the glands and organs of cattle and hogs and in
some cases wildlife for signs of bovine Tuberculosis. If these inspectors find
any lesions or other signs of bovine Tuberculosis, tissue samples are taken and
sent to APHIS, National Veterinarian Services Laboratories in Aimes, IA, for
confirmation. If the laboratory confirms that the lesions are a result of bovine
Tuberculosis, an attempt to track down the livestock from where it originally
came from and to find the herd that the infected cattle were affiliated with,
then a Tuberculin PPD (Purified Protein Derivative) (Bovine) test will be
administered to all of the herd. If the herd is infected with bovine
Tuberculosis the rest of the herd will be taken to the slaughterhouse to be
destroyed. If the whole herd can not be eliminated it is held under quarantine
and tested repeatedly until all evidence of infection is eliminated.
Veterinarians also try to find out the date that the herd was probably infected.
Then they try to trace all cattle that moved into or out of the affected herd
and try to find out where the infection probably started and where it might have
gone and where it might be going. Testing A skin test is the most reliable way
to identify bovine Tuberculosis in cattle. If cattle have been infected or
exposed to bovine Tuberculosis a reaction will occur at the test site on the
skin. (So far to date there is no effective vaccine or medications for treatment
for wild animals). If a reaction does occur an additional test is required to
identify which type of Tuberculosis that the animal is infected with. Once the
type is identified you would use a sterile liquid containing protein derivatives
from a heat killed Mycobacterium bovis (Strain AN 5), which is grown on a
synthetic medium. If the test resulted in the bovine Tuberculosis you would use
the Tuberculin PPD (Purified Protein Derivative) (Bovine). Retesting Retesting
may only be done at least 60 days after the last injection of Tuberculin PPD was
administered. This applies to either the intradermal caudal fold test or a
comparative test was completed. Dosage and Administration Use the single
intradermal test (skin test). Give a single intradermal 0.1-ml injection of
Tuberculin PPD (bovine) (The vaccine should be stored between 2 and 8 degrees
Celsius, but do not freeze and keep it out of the light). The caudal fold
(stomach or abdominal area) is where the Injection will be administered. Clean
the area thoroughly with Betadine or an iodine solution where the injection will
take place, for sterilization, prior to injection. Government actions In order
to protect the human population, the Government has introduced the following
actions: (1) Heat treatment of milk (Pasteurization). (2) Inspection of
carcasses at slaughterhouses. (3) Reduce the population of infected animals.
Summary It is highly unlikely (less then 1%) the humans will contract bovine
Tuberculosis from animals, but there is always the possibility of transmission
of the disease. If you do come in contact with an animal that has bovine
Tuberculosis you will need to get in contact your state or federal inspectors to
have the animal eradicated. 
Bibliography
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