Tuberculosis Case

Tuberculosis (TB) is caused by Mycobacterium tuberculosis (M.TB.) and is the leading cause

of death in the world from a single infectious disease. Although very little is known of the

mechanisms of it pathogenesis and how to protect a person from the disease. There was a

decline in TB in the United States in the last century but the disease is now increasing and

there are now multiple drug resistant strains that have emerged. This increase has multiple

causes some of which are changes in social structure in cities, HIV epidemic, and a failure by

some public entities to improve their public health programs.

In 2002 M. TB. is responsible for more morbidity in humans than any other bacterial disease.

M.TB. infects 1.7 billion people per year which is equal to 33% of the entire world population

and is responsible for over 3 million deaths/year. (Todar's 2002)

In the United States since 1985 there has been an increase in cases of M.TB. this is due

largely to the increase of Human Immunodeficiency virus (HIV) infections which occurred

during the same period of time. More recently there has also been an increase in the number

of cases of multi drug resistant (MDR) strains of M.TB. due to patient non compliance with

medication.

Mycobacterium tuberculosis is the cause of TB in humans. Humans are the only known

reservoir for the bacterium. Mycobacterium bovis is the etiologic agent of TB in cows and

rarely in humans, but both cows and humans can serve as reservoirs. Humans can also be

infected by consuming unpasturized milk. This method of transmission can cause the

development of extra pulmonary TB, as seen in history by bone infections that caused

hunched backs. (Todar's 2002).

Mycobacterium tuberculosis is a large nnonmotile rod shaped bacterium. The rods are 2-4

microns in length and 0.2-0.5 microns in width. Many non pathogenic mycobacteriums

compose the normal flora of humans most commonly found in dry or oily locales. M.TB. is not

classified as gram negative or gram positive because it does not have the chemical

characteristics, although if a gram stain is performed it is considered weakly gram positive or

not at all. M.TB. is classified as acid fast bacilli due to the impermeability of certain dyes and

stains (Todar's 2002)

Tuberculosis (TB) has two forms latent infection and disease. In the infection form of TB the

immune system is able to keep the bacteria under control. The body accomplishes this by

producing macrophages the surround the tubercle bacilli and forming a hard shell, thereby

isolating the M.TB. and keeping it under control. There are TB bacilli in the body, with the

number of organisms from 103-104, the TB skin test is usually positive, but the chest x-ray is

normal; and a sputum smear for acid fast bacilli (AFB) is negative, the patient has no signs or

symptoms of being infected TB and is not infectious.

In a person with the latent infection form of M.TB. there will be a positive TB skin test with no

other symptoms present. The chest X-ray will be normal and a sputum test for acid fast bacilli

will be negative. A person with this form cannot spread M. TB. to others.

A person with M.TB. disease will have a cough that lasts longer than 2 weeks, pain in the

chest, cough up blood or sputum. They will also experience fatigue, anorexia, weight