Tuberculosis (TB), a disease which man has been fighting for centuries and even had hopes of irradicating in the year 2000 is back in full swing. TB kills more adults than any other infectious disease. According to Internet source What is TB? "The World Health Organization (WHO) estimates that 8 million new cases and 3 million deaths are attributed to TB each year." The paper goes on to explain there are 26,000 new active cases reported yearly and is estimated that each person with untreated, active TB will infect 10 to 15 others every year (2). In March of 1998, there was an article in the Arizona Republic telling of a current TB case here in the Phoenix area. A portion of the article read, "The physician held up Madeleine Weekley’s chest x-ray and pointed to the quarter-size hole on the 32-year-old’s lung. The cavity could be caused by one of four things: lung cancer, pneumonia, valley fever or tuberculosis. "I don’t smoke, so I didn’t think it was lung cancer. I was praying for pneumonia. I never thought of TB," said Weekley, a communications specialist who went home and spent an anxious weekend waiting for test results. A sputum test narrowed in down to one culprit: tuberculosis" (1).
TB is an airborne bacterial disease and according to author Julliana Newman, today’s tuberculosis afflicts people of all ages, nationalities, and income levels and is more threatening and stronger than ever with its new antibiotic resistant mutations (392). Therefore, in order to gain some control on this re-appearance and prevent tuberculosis from exploding to epidemic proportions, we must increase public awareness and education to include early detection, proper treatment plans, and preventative measures.
Micobacterium TB
TB is caused by rod-shaped bacillus (germs) called Mycobacterium tuberculosis (Mtb). Mycobacterium is believed to be among the oldest bacteria on earth and are found as free-living organisms in the environment. These bacteria can be infectious to many animals including cattle and pigs as well as humans.
Mycobacterium TB is approximately 1 to 5 um in length and "has an unusual cell wall, a waxy coat comprised of fatty molecules whose structure and function are not well known (Tuberculosis (TB), a chronic bacterial infection 4). Not only does this cell wall make the bacteria more challenging for the human immune system; it also makes Mtb difficult to study in a laboratory setting. To the biologist, this bacterium is called "acid-fast" because this waxy coating on the walls keeps the cell from being decolorized during testing. They also multiply very slowly and tend to form clumps instead of colonies, making them microscopically harder to count and examine. Lastly, since Micobacteria are airborne, they must be studied in laboratories with special equipment to handle airborne contaminants.
TB is an airborne bacterial disease and according to author Julliana Newman, today’s tuberculosis afflicts people of all ages, nationalities, and income levels and is more threatening and stronger than ever with its new antibiotic resistant mutations (392). Therefore, in order to gain some control on this re-appearance and prevent tuberculosis from exploding to epidemic proportions, we must increase public awareness and education to include early detection, proper treatment plans, and preventative measures.
Micobacterium TB
TB is caused by rod-shaped bacillus (germs) called Mycobacterium tuberculosis (Mtb). Mycobacterium is believed to be among the oldest bacteria on earth and are found as free-living organisms in the environment. These bacteria can be infectious to many animals including cattle and pigs as well as humans.
Mycobacterium TB is approximately 1 to 5 um in length and "has an unusual cell wall, a waxy coat comprised of fatty molecules whose structure and function are not well known (Tuberculosis (TB), a chronic bacterial infection 4). Not only does this cell wall make the bacteria more challenging for the human immune system; it also makes Mtb difficult to study in a laboratory setting. To the biologist, this bacterium is called "acid-fast" because this waxy coating on the walls keeps the cell from being decolorized during testing. They also multiply very slowly and tend to form clumps instead of colonies, making them microscopically harder to count and examine. Lastly, since Micobacteria are airborne, they must be studied in laboratories with special equipment to handle airborne contaminants.
According to Newman, tuberculosis bacteria are not spread through touch or handling of personal items, but rather by inhalation. Tuberculosis is "spread when an infected person sneezes, coughs, speaks, or sings" (see figure 1) (383). When these actions occur, tiny particles known as droplets nuclei, which are basically microscopic drops of phlegm, are released into the air. If these droplets are expelled from an infected person, they will contain Mtb bacteria.
Most of the bacilli that do become airborne die before reaching a potential victim. However experiments under controlled temperature settings have shown airborne tubercles surviving for about six hours. "The probability of infection is proportional to the concentration of infectious droplets in the air and the volume of air breathed during exposure" (383). The Internet article titled Tuberculosis (TB), a chronic bacterial infection explains, "adequate ventilation is the most important measure to prevent the transmission of the disease" (4). Only the droplets expelled from an infected person with active TB contain bacilli. "Because most infected people expel relatively few bacilli, transmission of TB usually occurs only after prolonged exposure to someone with active TB. Researchers have estimated on average, people have a 50 percent chance of becoming infected with TB if they spend eight hours a day for 6 months or 24 hours a day for two months working or living with someone with active TB" (4). Most of these droplets die in transit. Only if the bacillus happens to survive long enough to be inhaled by a susceptible person can it then pass to the upper respiratory system. Nose hair and bronchial tube linings are designed to filter out bacterial pathogens. Therefore, "infection begins only if the bacilli make it deep inside the lungs to tiny air sacs known as alveoli, where they multiply within macrophages" (5). Once in the alveoli of the lung, the bacteria are ingested by alveolar macrophages, which are then modified to become epithelioid cells. Within two weeks, necrosis begins within the tissue containing these epithelioid cells, a process referred to as caseation (Newman, 383). The end result is a fully formed tubercle or small, rounded mass. These tubercles grow and fuse as the caseation process continues and wide areas of tissues are destroyed, which is indicative of active TB disease.
Most of the bacilli that do become airborne die before reaching a potential victim. However experiments under controlled temperature settings have shown airborne tubercles surviving for about six hours. "The probability of infection is proportional to the concentration of infectious droplets in the air and the volume of air breathed during exposure" (383). The Internet article titled Tuberculosis (TB), a chronic bacterial infection explains, "adequate ventilation is the most important measure to prevent the transmission of the disease" (4). Only the droplets expelled from an infected person with active TB contain bacilli. "Because most infected people expel relatively few bacilli, transmission of TB usually occurs only after prolonged exposure to someone with active TB. Researchers have estimated on average, people have a 50 percent chance of becoming infected with TB if they spend eight hours a day for 6 months or 24 hours a day for two months working or living with someone with active TB" (4). Most of these droplets die in transit. Only if the bacillus happens to survive long enough to be inhaled by a susceptible person can it then pass to the upper respiratory system. Nose hair and bronchial tube linings are designed to filter out bacterial pathogens. Therefore, "infection begins only if the bacilli make it deep inside the lungs to tiny air sacs known as alveoli, where they multiply within macrophages" (5). Once in the alveoli of the lung, the bacteria are ingested by alveolar macrophages, which are then modified to become epithelioid cells. Within two weeks, necrosis begins within the tissue containing these epithelioid cells, a process referred to as caseation (Newman, 383). The end result is a fully formed tubercle or small, rounded mass. These tubercles grow and fuse as the caseation process continues and wide areas of tissues are destroyed, which is indicative of active TB disease.
This process, however, in a healthy immune system, is usually kept in check. The bacteria aren’t allowed to proliferate and, although the germ exists in the patient’s body, it doesn’t make the person sick. "The immune system ‘walls off’ the TB bacilli which, protected by a thick waxy coat, can lie dormant for years and years" (Tuberculosis Fact Sheet 1). These ‘walled off’ inactive bacilli aren’t considered damaging or contagious, although these patient’s will have a positive tuberculin skin test (see figure 2).
People infected with the TB germ are at a greater risk of developing the active disease during the first two years post infection, but can develop TB many years after exposure, especially if the immune system should become weakened. "On average, people infected with M. Tuberculosis have a 10 percent chance of developing active TB at some time in their lives" (Tuberculosis (TB), a chronic bacterial infection 6).
People infected with the TB germ are at a greater risk of developing the active disease during the first two years post infection, but can develop TB many years after exposure, especially if the immune system should become weakened. "On average, people infected with M. Tuberculosis have a 10 percent chance of developing active TB at some time in their lives" (Tuberculosis (TB), a chronic bacterial infection 6).
CLINICAL ASSESMENT
A prompt and accurate diagnosis is a key component to limiting the spread of TB. Newman explains that "prolonged exposure to undiagnosed patients with MDR-TB is directly related to the present proliferation in reported cases" (388). Anyone who experiences a combination of fever, night sweats, unexplained weight loss, a loss of appetite, a chronic cough, or coughs up blood, could be actively infected and should be tested (Treatment of Tuberculosis Infection/AAFP Pa, 1). Also, anyone who has close day-to-day contact with someone who has active TB disease (i.e. a family member, friend or co-worker) should be tested. Individuals with HIV infection or other immunosuppressive disorders as well as workers who might be in frequent contact with TB patients, such as correctional officers and health care employees, should also be periodically tested.
Testing usually always begins with the Mantoux (PPD) skin test. "A substance called purified protein derivative (PPD) is injected just under the skin of the forearm and examined about 48 to 72 hours later." A positive test is indicated when this area appears red and hardened (Tuberculosis (TB), a chronic bacterial infection 6,7). However, a positive skin test does not mean the patient has active TB disease. In most cases, just being exposed to micobacterium will produce a positive reaction. Remember that you can be exposed to the bacteria without developing active TB disease. Therefore, a positive test reading should be followed with an additional Mantoux test and a standard chest x-ray. If these initial test results continue to produce positive results, sputum and other samples are usually requested as a laboratory culture is necessary to confirm the TB diagnosis and to determine which anti-TB drugs will be most effective. "Since M. tuberculosis is slow-growing, it takes approximately a month to get the sputum culture results. An additional two to three weeks usually are needed to determine the drug susceptibility of the organism, making treatment decisions difficult." (Tuberculosis (TB) a chronic bacterial infection 7).
Recently, advances have been made in research, which has led to the development of new laboratory culture tests capable of producing results in two days by using "nucleic acid amplification." "Another test in development uses luminescent chemicals from the firefly to determine, in 24 to 48 hours, which drugs can kill the TB strain a patient caries" (Tuberculosis (TB), a chronic bacterial infection 7).
If treatment of active TB is indicated, it normally involves a combination of three anti-TB drugs, isoniazid, rafampin, and pyrazinamide. These drug combinations are usually prescribed for a minimum of 6 months, what is referred to as a short course chemotherapy. At this point, patient education is crucial to the success of the treatment plan, and it is extremely important that the medications be taken as long as is prescribed. Again, stopping the medication early is what leads to the development of multi-drug resistant strains (MDR-TB) Consequently; "treatment for MDR-TB often requires the use of a second line of drugs, all of which can produce serious side effects. Drug therapy for 18 months to 2 years may be necessary" (Tuberculosis (TB), a chronic bacterial infection 2, 8). Prevention of TB begins with the diagnosis. Newman writes that "prompt and accurate diagnosis is key to controlling the spread of tuberculosis" (384). Extra attention should be given to those at highest risk of developing the disease and treatment plans utilizing DOTS should be initiated.
In the workplace, prevention for health care workers who care for high-risk patients, or who might be involved in procedures, which could increase the risk of exposure, should have a Mantoux skin tests every six months. Hospitals and clinics can further protect the population by teaching patients to cover their nose and mouth when coughing or sneezing. They can also make use of "Ultraviolet light to sterilize the air along with negative pressure rooms and special room air filters" (Tuberculosis (TB), a chronic bacterial infection 9). Special MTB masks that filter out the droplets nuclei should be provided along with proper use instructions.
Testing usually always begins with the Mantoux (PPD) skin test. "A substance called purified protein derivative (PPD) is injected just under the skin of the forearm and examined about 48 to 72 hours later." A positive test is indicated when this area appears red and hardened (Tuberculosis (TB), a chronic bacterial infection 6,7). However, a positive skin test does not mean the patient has active TB disease. In most cases, just being exposed to micobacterium will produce a positive reaction. Remember that you can be exposed to the bacteria without developing active TB disease. Therefore, a positive test reading should be followed with an additional Mantoux test and a standard chest x-ray. If these initial test results continue to produce positive results, sputum and other samples are usually requested as a laboratory culture is necessary to confirm the TB diagnosis and to determine which anti-TB drugs will be most effective. "Since M. tuberculosis is slow-growing, it takes approximately a month to get the sputum culture results. An additional two to three weeks usually are needed to determine the drug susceptibility of the organism, making treatment decisions difficult." (Tuberculosis (TB) a chronic bacterial infection 7).
Recently, advances have been made in research, which has led to the development of new laboratory culture tests capable of producing results in two days by using "nucleic acid amplification." "Another test in development uses luminescent chemicals from the firefly to determine, in 24 to 48 hours, which drugs can kill the TB strain a patient caries" (Tuberculosis (TB), a chronic bacterial infection 7).
If treatment of active TB is indicated, it normally involves a combination of three anti-TB drugs, isoniazid, rafampin, and pyrazinamide. These drug combinations are usually prescribed for a minimum of 6 months, what is referred to as a short course chemotherapy. At this point, patient education is crucial to the success of the treatment plan, and it is extremely important that the medications be taken as long as is prescribed. Again, stopping the medication early is what leads to the development of multi-drug resistant strains (MDR-TB) Consequently; "treatment for MDR-TB often requires the use of a second line of drugs, all of which can produce serious side effects. Drug therapy for 18 months to 2 years may be necessary" (Tuberculosis (TB), a chronic bacterial infection 2, 8). Prevention of TB begins with the diagnosis. Newman writes that "prompt and accurate diagnosis is key to controlling the spread of tuberculosis" (384). Extra attention should be given to those at highest risk of developing the disease and treatment plans utilizing DOTS should be initiated.
In the workplace, prevention for health care workers who care for high-risk patients, or who might be involved in procedures, which could increase the risk of exposure, should have a Mantoux skin tests every six months. Hospitals and clinics can further protect the population by teaching patients to cover their nose and mouth when coughing or sneezing. They can also make use of "Ultraviolet light to sterilize the air along with negative pressure rooms and special room air filters" (Tuberculosis (TB), a chronic bacterial infection 9). Special MTB masks that filter out the droplets nuclei should be provided along with proper use instructions.
source:www.gwc.maricopa.edu
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