TB, or Tuberculosis, is a chronic or acute contagious disease caused by a bacterial infection. TB is the leading cause of death from a single infectious disease, accounting for over a quarter of avoidable deaths among adults. It can affect several organs of the human body, including the brain, the kidneys and the bones, but it predominately manifests itself in the lungs where it is called “Pulmonary Tuberculosis”. According to the WHO, TB infection is currently spreading at the rate of one person per second.
It kills more young people and adults than any other infectious disease and is the world’s biggest killer of women. Researchers have calculated that 8-10 million people catch the disease every year, with three million dying from it. It causes more deaths worldwide than AIDS and Malaria combined. The WHO predicts that by 2020 nearly one billion people will be newly infected with TB, of them 70m will die. TB black spots include Eastern Europe with 250,000 cases a year, South East Asia; three million cases a year and sub-Saharan Africa with two million cases a year.
Tuberculosis, a sometimes crippling and deadly disease, is on the rise and is revisiting both the developed and developing world. The global epidemic is growing and becoming more dangerous. The breakdown in health services, the spread of HIV/AIDS and the emergence of multi drug-resistant TB are contributing to the worsening impact of this disease. Overall, one-third of the world’s population is currently infected with the TB bacillus. How TB Spreads: TB is a contagious disease. Like the common cold, it spreads through the air.
A person acquires a tuberculosis infection by inhaling tiny droplets of moisture contaminated with the Mycobacterium Tuberculosis bacteria. The source of these droplets is frequently from infectious individuals who expel thousands of water droplets into the air every time they cough, sneeze, talk or spit. A person needs only to inhale a small number of these to be infected. The most common places for becoming infected with TB are right in your own home, or your workplace. Often the source of the infection is unknown since the initial infection may have occurred several years ago.
Left untreated, each person with active TB will infect on average between 10 and 15 people every year and these people are mostly likely to be family members, friends, coworkers, and those who share the same breathing space. However, TB infections are not readily acquired under most circumstance and usually do not occur vial casual contact on the street or bus. Only about 5 – 10 percent of people who are infected with TB become sick or infectious at some time during their life. What are the Chances of Becoming Infected?
The process of catching Tuberculosis involves two stages: first, a person has to become infected; second, the infection has to progress to disease. To become infected, a person has to come in close contact with another person having active Tuberculosis disease (in the lungs and throat only, since TB in other body parts are not infectious), with TB germs present in the sputum. However, the likelihood of this happening also depends on the time spent in close contact with the person with active disease. It has been proven that a person who is taking their TB pills cannot pass on Tuberculosis.
The process of infection progresses to disease in about 10% of those infected, and it can happen anytime during the remainder of their lives. Although the chance of progression to disease diminishes with the passage of time, TB can develop more easily if the immune system weakens. Babies, young children and the elderly often have weak immune systems. Others who are immune-compromised, and thus more susceptible include those with: AIDS, Substance abuse, Diabetes mellitus, Silicosis, Cancer of the head or neck, Leukemia or Hodgkin’s disease, Severe kidney disease, Low body weight, Malnutrition,
Alcoholism, Those undergoing chemotherapy, Transplant recipients taking anti-rejection medications. The disease is often perceived as most frequently affecting the elderly, and in industrialized countries a quarter of all cases occur in those over 65. But in the developing countries of Africa and South America, TB is most common among young adults. Women of childbearing age between the ages of 15 and 44 are more likely than men of the same age to fall sick with the disease. Women in this age group are also at greater risk from HIV infection, which makes them more susceptible to TB too.
What is TB Infection? In most people who breathe in the bacteria and become infected, the body is able to fight the bacteria stop growing. This is the first stage, called “Early Infection”, which often heals without being noticed or might be passed off as a “cold or flu”. The second stage of TB, called “Dormant TB” or “Sleeping TB”, occurs when germs remain in the body and may be wide spread, but seem to have no effect on the health of their host. The bacteria become inactive, but they remain alive and can become active later. This is called TB Infection.
People with TB infection have no symptoms, don’t feel sick, can’t spread TB to others, usually have a positive skin test reaction or can develop TB later in life if they do not receive preventive therapy. What Is Active TB? The third stage of TB may develop when the dormant infection “wakes up” and causes sores in the lungs and other parts of the body. This third stage is referred to as “Active TB”, or TB Disease. A person can develop active TB either soon after being infected, or later when their immune system becomes weak for some reason.
The Tubercle bacillus can spread from the localized infection to throughout the body such as throughout the lungs, airway passages, the pleural space, blood vessels and in the blood stream it can even spread to other organs like the lymph nodes. The usual site of the disease is the lungs, but other organs may be involved. Generally, the active disease is manifested by destruction or “consumption” of the tissues and the development of granulomas (granular tumors) in the infected tissues. The symptoms of the disease vary according to which body organ is infected.
The common symptoms however, usually include Sweating, Fatigue, General discomfort, Uneasiness, or ill feeling (malaise), Weight loss, Cough, Fever, Shortness of breath. Types Of Tuberculosis: TB can be categorized into two different types, according to where it has manifested itself. These two types are described as: Pulmonary Tuberculosis and Non-Pulmonary Tuberculosis. Pulmonary Tuberculosis accounts for most cases of infection by Mycobacterium Tuberculosis as well as for about 85 % of all Tuberculosis deaths.
Primary infection of the lung generally occurs in the lower division of the bottom lobe, the middle lobe, and the anterior segment of the upper lobe. These sites obtain the greatest volume of airflow and, therefore, bacilli are deposited there in the greatest numbers. However, TB tends to localize most often at the apex of the upper lobe of lungs. This localization pattern is attributable to two reasons: first, the concentration of oxygen at the apex is greater than other portions of the lung; and second, venous and lymphatic fluid pressures are lower at the apex.
When the bacillus population becomes large enough, they cause symptoms like anorexia, diminished respiratory capacity, fatigue, weight loss, chilly sensations, afternoon remittent fever and night sweats. Associated chest pain is also sometimes felt which is usually due to inflammation of the parietal pleura. In addition to the symptoms of Pulmonary Tuberculosis stated above, another symptom deserves special mention because it is recognizable as the “cinematic symptom” of TB. A Tuberculosis lesion that perforates a venous wall can cause Haemophtysis, which is the expectoration of bloody sputum through coughing.
The hemophtysic cough is also highly characteristic of Pulmonary Tuberculosis. Non-Pulmonary Tuberculosis in a general sense, describes a TB infection that has disseminated, or spread, to various sites in the body from the lungs. The Tubercle bacilli usually disseminate through out the body during the early stages of infection. From here (usually the blood stream) they can infect various sites. Although no organ or site in the body is immune to the TB bacillus, certain areas are of special concern due to their vulnerability and vital functions.
Non-Pulmonary TB is very common among patients with an HIV infection in conjunction with Pulmonary TB. 60-80% of these patients develop non-Pulmonary TB in contrast to 17% of non-HIV patients who develop non-Pulmonary TB. Extra-pulmonary TB is considered an AIDS defining disease by the Center for Disease Control (CDC). Tuberculosis of the Spine (Tuberculous Spondylitis): This is characterized by softening and collapse of the vertebrae, often resulting in a hunchback deformity. The condition is named after an English surgeon, Sir Percivall Pott, who described it in a monograph published in 1779.
The infection begins in the body of the vertebra (the most common site of bone Tuberculosis) and spreads slowly to contiguous structures. Abscesses may form, migrate, and cause pain in sites quite distant from the spine. Occasionally, the spinal nerves are affected, and a rigid paralysis may result. Affected persons complain of pain on movement and tend to assume a protective, stiff position. Spinal TB symptoms may include: loss of appetite, night sweats, malaise, (a vague feeling of physical discomfort) and evening rise in temperature.
Other effects such as stiff painful movement of the spine and localized deformity and spasm of muscles are more common to more progressive stages of the infection. The course of the disease is slow, lasting months or years. Bone and Joint TB: After infection of the spine, Tuberculosis can spread via the blood to other areas. Other common sites for extra Pulmonary TB infections in the bones and joints include knees (15%), hip (15%) and other weight bearing joints. It is spread via the blood by small Tubercle bacilli, which cause small lesions (damage) in the bone marrow.
Symptoms of bone and joint are pain, localized swelling, fever and weight loss. In progressive stages of the disease, Tuberculosis may cause Paraplegia (paralysis of the lower part of the body) in severe and extreme cases if untreated. Central Nervous System Tuberculosis (Meningeal): The meninges are membranes that envelop the brain. Meningeal or CNS TB deals with the basal meninges, or those located near the brain stem, which is the most common site. Meningeal TB occurs in three stages depending on time of infection. Symptoms are classified into three stages.
The first stage can include: nonspecific symptoms, headache, fever, irritability, and sleepiness. The second stage is characterized by sudden appearance of: lethargy, convulsions, nuchal rigidity, (stiffness of the nape of the neck) vomiting, meningeal irritation, and increased intracranial pressure. The final stage brings: irregular pulse, altered mental state, cranial nerve lesions (damage), respiratory hemiplegia, (half-paralysis) paraplegia or paralysis of the waste down, coma and eventually death. Pericardial Tuberculosis: This is TB that occurs in the heart.
Pericardial Tuberculosis is a fairly recent problem because of its uncommon presence in the pre-AIDs era. It usually occurs as a late effect of Pulmonary Tuberculosis. Pericardial Tuberculosis can also occur from the spreading of Plural Tuberculosis to pericardial. Symptoms of Pericardial Tuberculosis can vary depending on the case. Some of the less severe complications include coughing, vague discomfort, and difficult or labored respiration. Acute pain is occasionally suffered in some cases, and in the most severe situations a frictional rub of the heart and escape of fluids into other cavities can occur.
Gastrointestinal Tuberculosis (Peritoneal TB): The peritoneum is a membrane lining the cavity of the abdomen. Peritoneal TB occurs when tubercle bacilli, coughed up from a primary infection in the lungs, are swallowed. The tubercles can form lesions on the peritoneum, which can spread to other organs, or the organs can spread the infection to the peritoneum. Infection of the gastrointestinal tract can include common symptoms such as fever, weight loss, anorexia, abdominal swelling, vague pain in the stomach, and bowel habit abnormalities. Other recognizable problems include obstruction, perforation or ulceration, and fistula (channeling. )
What Causes Tuberculosis? TB is caused by a fungus-like bacterium that belongs to a special group of microorganisms called mycobacterium. The species of bacteria that most commonly infect humans is called Mycobacterium Tuberculosis complex (called “MTB” for short. ) Robert Koch first discovered this in 1882. Tuberculosis in humans is usually caused by the human variety of the mycobacterium, M. Tuberculosis, and in fewer cases by the bovine variety, M. bovis. Besides cattle, which are infected by the bovine type of bacillus, other domestic animals susceptible to tuberculosis include swine and fowl, the latter being infected by the avian type.
Strains of Mycobacteria africanum have also been found in Africa. Mycobacteria: Mycobacteria are long, rod-shaped cells that develop into long chains that look a bit like a string of sausage links when viewed under a microscope. Many bacteria cells are long and slender like this and are known as “bacilli”. This is why the tubercle-forming TB bacteria are often called “Tubercle bacilli”. Genetically speaking, Mycobacterium Tuberculosis is unusual in several aspects, making it a difficult organism to study. One of these peculiarities is the high content of cytosine and guanine in its DNA.
This high level of CG may be a survival strategy employed by the bacteria: heat-stability of DNA increases with the number of C-G bonds. The walls of Mycobacteria are also very special. They are made of 60% “mycolic acid”, a special lipid substance that is only found in Mycobacteria. This mycolic acid makes the cells hydrophobic –an effect that is much like pouring water over a surface that is covered with margarine. The success of M. Tuberculosis as a pathogen would not be possible without the role played by it’s cell wall.
The cell wall is responsible for protecting the cell and regulating the interaction between the bacillus and it’s environment (the human body). This is why, even today MTB is difficult to stain for identification, and lab workers have to use a special technique to distinguish these bacteria. Mycobacteria are aerobic, which means they like to grow in an environment with oxygen, and a bit of carbon dioxide as well. Mycobacteria do not like Ultraviolet (UV) rays from the sun. MTB is susceptible to inactivation from UV light and this is the reason why TB patients were once prescribed suntan for treatment of their disease.
Like many Mycobacteria, MTB is also heat-sensitive. Milk producers have been required by law to heat all milk to a certain temperature for a specific length of time to kill all Mycobacteria present in developed countries. It is because of this pasteurization that bovine tuberculosis is not common anymore, except in third world countries. Detection and Diagnosis: Enlarged lymph nodes, enlarged liver, and enlarged spleen are revealed with physical exam, but these are not confirmatory tests for TB. The initial diagnostic/screening test to find out if a person has TB infection is the TB skin test.
The test consists of scratching the skin with a protein substance derived from cultures of tubercle bacilli. Although there is more than one TB skin test, the preferred method of testing is to use the Mantoux test. For this, a small amount of testing material is placed just below the top layers of skin, usually on the arm. Two to three days later a health care worker checks the arm to see if a bump has developed and measures the size of the bump. If the bump is of a certain size (varying with group) the test is positive. A positive skin reaction indicates the presence of tuberculosis, whether active or inactive.
To ascertain whether there is any active disease, diagnosis is made by the detection of tubercle bacilli in the sputum. The standard chest X-ray also provides a method of mass screening of people for evidence of early pulmonary tuberculosis. Although an X-ray will reveal the presence of a lung lesion, confirmation of its nature requires further testing. A physician or a trained health professional will also review your history and may order further tests, if necessary. If you are diagnosed as having active TB, you will be required to take medications as prescribed by the physician.
Compared to pulmonary TB, diagnosis of non-pulmonary TB is usually problematic due to the inaccessibility of the sites of infection and the relatively small number of bacilli present in many infection sites. Other tests such as bronchoscopy and biopsies of affected organs or tissues are used to determine whether a person has TB. How to Treat Tuberculosis: The goal of treatment is to cure the infection with antitubercular drugs. Daily oral doses of rifampin, isoniazid, pyrazinamide and thambutol (or Streptomycin) are given for a period of 3 months.
This is followed by a continuation phase consisting of rifampicin, isoniazid and ethambutol for next 9 months; thus completing one-year treatment. For atypical Tuberculosis infections, or drug-resistant strains, other drugs may be indicated to treat the infection. Normal activity can be continued after the infectious period. Rest, a healthy environment (clean dry air), stress reduction and a good diet high in vitamin C, factors normally considered conducive to good health, improve the speed and response to treatment. It is very important, however, that the patient continue to take the medicine correctly for the full length of treatment.
If the medicine is taken incorrectly or stopped the patient may become sick again and will be able to infect others with TB. As a result many public health authorities recommend Directly Observed Therapy (DOT), in which a health care worker insures that the patient takes his/her medicine. If the medicine is taken incorrectly and the patient becomes sick with TB a second time, the TB may be harder to treat because it has become drug resistant. Hospitalization is only in seriously ill patients, but once the disease has been brought under control the patient may return to normal activity; complete treatment usually takes one year.
Expectations (Prognosis): Symptoms may improve in 2 to 3 weeks, with improvement seen in the chest X-ray lagging behind clinical improvement. Complications: All medications used to treat TB have some toxicity. Rifampin and isoniazid may both cause a noninfectious hepatitis. Rifampin may also cause an orange or brown coloration of tears and urine. Other complications include drug resistance to particular TB strains and a relapse of the disease in some patients. Preventions Routine skin testing for tuberculosis is done during routine well-baby exams. Infants are normally screened at 1 year and children at 5 years.
Individuals exposed to tuberculosis should be skin tested immediately and the skin test repeated in 3 to 6 months if the initial skin test is negative. The importance of the skin test is that it shows if you have been exposed to Tuberculosis; it helps determine if you are at risk for developing the disease and treatment can be provided before you become sick. Detection of early cases and prompt treatment are paramount in controlling the spread of tuberculosis. (BCG): The BCG Vaccine was derived from a strain of M. bovis in France by Calmette and Guerin. BCG does not prevent initial infection, but does prevent the spread of the infection.
The vaccine, which consists of a live bacterium, was first administered in 1921 and now exists in several forms. The BCG vaccines vary substantially in effectiveness, ranging from 0-80%. The vaccine is still heavily relied upon in many countries to protect infants from the life threatening disease. But in countries where the general population is at low risk of acquiring TB, the BCG vaccines are not widely used. Instead a positive skin test and drug therapy of isoniazid and rifampin are relied upon. After vaccination the widely used TB skin test will cause a false positive.
The benefit of the skin test is considered more valuable then widespread vaccination of a population not at risk. Studies have shown, however, that although this vaccine protects some people, many are either not protected at all, or are immune for only a short time. BCG vaccination is not a guarantee against becoming infected with TB, and a positive TB test is probably not due to prior vaccination with BCG. BCG is not administered to patients who have compromised or suppressed immune systems; HIV, lymphoma, leukemia, radiation treatment, transplant recipients, etc.
For this group vaccination increases the risk of developing TB and consequently death. This means that the BCG vaccine is sometimes not available to those who need it the most. As mentioned before, Bovine TB has been effectively countered by the popularization of pasteurization of milk. It is only in third-world countries that Bovine TB is still detected. In such places, cattle should be routinely screened for the infection, and infected cows should be slaughtered and incinerated. History of Tuberculosis: There is evidence that man has suffered from Tuberculosis for more than 5,000 years.
Tuberculosis bones and the remnants of old Tuberculosis adhesions in the chest have even been found in Egyptian mummies dating back to 1500B. C. The disease was well recorded by Hippocrates, (460-370 BC) the father of medicine, who described Pulmonary Tuberculosis as occurring in day-to-day clinical experience. Over the years, a number of different names have been given to this disease, such as Consumption, miasma, scrofula, phthisis, Pott’s disease, Lupus vulgaris and cutaneous infection. Many prominent physicians and doctors were concerned with the symptoms and possible cures of T.
B, as we can see in the History of Tuberculosis Timeline. However, before any significant advances were made in identifying the causes and how to properly treat TB, mankind had come up with many different preventive measures and cures, ranging from the surprisingly insightful to the silly. The common measures were: Avoiding garbage form which ‘miasmas’ emanated. No spitting, covering mouth when coughing. Isolation of diseased. Burning possessions of deceased patients. Pasteurization of cow’s milk. Legislation designed to prevent spread.
Other treatments include Artificial Pneumothorax (compression of the affected lung by the introduction of gas or filtered air into the pleural cavity, which was to be continued for a period of from two to four or more years) and Thoracoplastly (removal of the ribs on one side of the thorax to accomplish a permanent collapse of the affected). Some physicians instructed patients to eat only ‘animal foods’ or to drink the warm milk of a goat, donkey and cow. In 1821 the ‘Nantucket Inquirer’ encouraged drinking strange concoctions and inhaling the smoke from burning rosin or the steam of boiling tar to strengthen one’s lungs.
Many early physicians felt that southern climates and sunshine were key elements in the treatment of a TB patient and in the 1880’s in the United States hundreds of people moved to Arizona with the belief that this climate might cure their TB. In some countries in the Middle Ages, kings were considered to posses miraculous powers of healing. For many centuries the kings of France and England used to “touch for Scrofula” – that is, they claimed to be able, simply by their touch, to cure people suffering from this disease, and their subjects shared a common belief in their powers.
The picture shows Charles II ‘touching for Scrofula’. Famous people afflicted with T. B include : John Keats ,poet John Harvard, founder Harvard University. Robert Louis Stevenson ,writer Max Lurie ,TB researcher who developed immune and susceptible inbred rabbits Charlotte and Emily Bronte ,writers. Another famous T. B victim is Katherine Mansfield , whose personal journal included the following entry: “August . I cough and cough, and at each breath a dragging, boiling, bubbling sound is heard. I feel that my whole chest is boiling. I sip water, spit, sip, spit. I feel I must break my heart.
And I can’t expand my chest; it’s is though the chest had collapsed…. Life is–getting a new breath. Nothing else counts. ” Re-emergence of T. B: While TB has long been a major problem in developing countries, by the 1960’s it was widely thought to have been eliminated in the developed world as a result of improved social conditions, mass screening, and the effective use of antibiotics and the BCG vaccine. After the 1960’s, the perception was that Tuberculosis will automatically be eliminated from industrialized countries and would steadily decline in developing countries with the discovery of effective chemotherapy.
But, many countries have had no strategy, no sharply focused plan and few resources to combat TB for the last two decades. Migration, international travel and tourism are increasingly allowing TB to penetrate borders. As a result, Tuberculosis has had a major rebirth in the 1990’s. Improper detection and misdiagnosis caused less than half the estimated 8 million cased in 1990 to be detected, and of those detected less than half were successfully treated. According to the World Health Organization, the worldwide increase in TB is such that in 1996 more people were infected with the disease than at any other time.
Each year, more people are dying of TB. New outbreaks have occurred in Eastern Europe, where TB deaths are increasing after almost 40 years of steady decline. In terms of numbers of cases, the biggest burden of TB is in south-east Asia. TB kills about 2 million people each year. Around 8 million people become sick with TB each year. Over 1. 5 million TB cases per year occur in sub-Saharan Africa. This number is rising rapidly as a result of the HIV/AIDS epidemic. Nearly 3 million TB cases per year occur in south-east Asia.
Over a quarter of a million TB cases per year occur in Eastern Europe. Factors Contributing to the Rise in TB The global resurgence of TB is being accelerated by the spread of human immunodeficiency virus (HIV), the causative agent of AIDS. Of the 14 million people in the world who were HIV positive in 1994, some 5. 6 million were believed to be infected with TB as well. TB and HIV form a deadly combination, each multiplying the impact of the other. When people are infected with both TB and HIV, TB is much more likely to become active because of the person’s weakened immune system.
As more TB cases become infectious, it means that larger numbers of people carry and spread TB to healthy populations. TB is already the leading cause of death among people who are HIV-positive, accounting for almost one third of fatalities worldwide and about 40% in Africa. Preliminary studies show that it is the leading opportunistic disease in 50-70% of AIDS patients in parts of Asia, where the HIV virus is spreading more rapidly than anywhere else in the world. Poorly managed TB programs are threatening to make TB incurable Until 50 years ago, there were no drugs to cure TB.
Now, strains that are resistant to a single drug have been documented in every country surveyed and, what is more, strains of TB resistant to all major anti-TB drugs have emerged. A particularly dangerous form of drug-resistant TB is multidrug-resistant TB (MDR-TB), which is defined as the disease due to TB bacilli resistant to at least Isoniazid and Rifampicin—the two most powerful anti-TB drugs. MDR-TB is rising at alarming rates in some countries, especially in the former Soviet Union, and threatens global TB control efforts.
Drug-resistant TB is caused by inconsistent or partial treatment, when patients do not take all their drugs regularly for the required period because they start to feel better, doctors and health workers prescribe the wrong treatment regimens or the drug supply is unreliable. While drug-resistant TB is treatable, it requires extensive chemotherapy (up to two years of treatment) that is often prohibitively expensive (often more than 100 times more expensive than treatment of drug-susceptible TB), and is also more toxic to patients. Treating patients with drug resistant TB is also beyond the pocket of many developing countries.
The cost of treatment can rise from $2000 per patient with non-resistant TB to $250,000 for multi-drug resistant TB. Movement of people is helping the spread of TB. Global trade and the number of people traveling in airplanes have increased dramatically over the last forty years. In many industrialized countries, at least one-half of TB cases are among foreign-born people. The number of refugees and displaced people in the world is also increasing. Untreated TB spreads quickly in crowded refugee camps and shelters. It is difficult to treat mobile populations, as treatment takes at least six months.
As many as 50 percent of the world’s refugees may be infected with TB. As they move, they may spread TB. Other displaced people such as homeless people in industrialized countries are at risk. In 1995, approximately 30 percent of San Francisco’s homeless population and 25 percent of London’s homeless were reported to be infected with TB. These figures compare to overall prevalence of 7 percent in the United States and 13 percent in the United Kingdom. The prevalence of infection in prisons can be even higher. A majority of the world’s health care systems are doing a poor job of curing TB patients.
The World Health Organization (WHO) estimates that fewer than 30% of all countries are beginning to follow the control policies recommended by WHO. Without question, lack of effective TB programs around the world is the primary reason that the TB epidemic is out of control. In many countries, particularly southern Asia, patients are diagnosed only on the basis of X-ray shadows. As a result, many people with other lung diseased or who have had TB in the past but who are now cured have shadows on their X-ray and are incorrectly diagnosed with tuberculosis.
Many countries are still not properly using short-course chemotherapy to treat their patients. They often adhere to a 12-month “long-course” treatment that is initially less expensive until one adds the cost increased treatment failures. The situation is even worse in some parts of the world, where treatment practices are accomplishing nothing other than creating drug-resistant TB. For example, in a survey of 100 doctors in Bombay, it was found that up to 80 different drug combinations were being used, most of which were inappropriate. WHO Tuberculosis: Strategy and Operations Goals:
To reduce TB morbidity and deaths by promoting the world-wide use of DOTS and other effective TB control strategies to assess existing strategies, and develop new strategies for the prevention and control of TB through operational, epidemiological, and economic research Objectives: to develop a global plan for the control and prevention of TB, and to assist countries in its implementation to promote the wide-spread use of DOTS; the potential of this cheap and effective strategy to reduce TB morbidity and deaths has not yet been realized in all settings to assess the impact of DOTS in specific settings and globally to design new approaches to TB control addressing the specific problems of TB/HIV, drug resistance and inequalities in access to health services The WHO-recommended treatment strategy for detection, cure and effective TB control is DOTS (Directly Observed Treatment). DOTS combine five elements: political commitment, microscopy services, drug supplies, surveillance and monitoring systems and use of highly efficacious regimes with direct observation of treatment.
Once patients with infectious TB have been identified using microscopy services, health and community workers and trained volunteers observe and record patients swallowing the full course of the correct dosage of anti-TB medicines (treatment lasts six to eight months). Sputum smear testing is repeated after two months, to check progress, and again at the end of treatment. A recording and reporting system documents patients’ progress throughout, and the final outcome of treatment. DOTS produces cure rates of up to 95 percent even in the poorest countries. DOTS prevents new infections by curing infectious patients. DOTS prevents the development of MDR-TB by ensuring the full course of treatment is followed.
A six-month supply of drugs for DOTS costs US $11 per patient in some parts of the world. The World Bank has ranked the DOTS strategy as one of the “most cost-effective of all health interventions. Since DOTS was introduced on a global scale, millions of infectious patients have received effective DOTS treatment. In half of China, cure rates among new cases are 96 percent. In Peru, widespread use of DOTS for more than five years has led to the successful treatment of 91 percent of cases. By the end of 1998, all 22 of the high burden countries which bear 80% of the estimated incident cases had adopted DOTS. 43 percent of the global population had access to DOTS, double the fraction reported in 1995. In the same year, 21 percent of estimated TB patients received treatment under DOTS, also double the fraction reported in 1995. WHO targets are to detect 70 percent of new infectious TB cases and to cure 85 percent of those detected.
Six countries had achieved these targets in 1998. Governments, non-governmental organizations and civil society must continue to act to improve TB control if we are to reach these targets worldwide. Prevalence of Tuberculosis Around the World Prevalence of Tuberculosis Around the World with Specific Case-Control Sites Global Epidemiology Tuberculosis (TB) is the leading cause of death from a single infectious disease, accounting for over a quarter of avoidable deaths among adults. This disease has affected all major regions of the world. The purpose of this report is to give the reader an idea of how dominating and debilitating this disease has proved to be.
In addition, the need to control tuberculosis is evident throughout the world and various control programs have recently been implemented. Tuberculosis is a global epidemic that has reached staggering morbidity and mortality rates. Based on the results, the greatest concentration of reported TB infections occurred in Southeast Asia. This makes up almost half the total reported cases in the world. Furthermore, the number of cases in American and European populations has decreased since 1986. Although the data from 1984-1991 suggests that the American rates of TB cases will continue to drop, there has been an unexpected 14% increase in TB cases in the United States from 1985-1993 (Raviglione, 1995).
This means that a significant increase in the number of TB cases must have occurred between 1991-1993. Among those more susceptible to the disease were young (25 yrs. d) to middle-aged people. Overall, non-US-born individuals accounted for 60% of the increase in cases from 1986 through 1992. HIV infected individuals also account for a high percentage of a recent rise in reported tuberculosis cases. In Canada, a rate of 0. 5 per 100,000 individuals has been maintained in recent years (Raviglione, 1995). Tuberculosis has had varying trends of occurrence throughout European countries. Most recently, western European countries have case notification rates ranging from 7. 0 in Denmark and Sweden to 55. 7 in Portugal per 100,000 residents.
In Eastern Europe, the rates are higher than those of the west ranging from 20. n the Czech Republic to 79. 6 in Romania per 100,000. Notification rates are also different in countries such as Australia, Japan, and New Zealand. TB cases from 1986 through 1992 have remained stable at an average of 5. 7 in Australia. Almost three-fourths of the cases were due to non-Australian-born individuals (Raviglione, 1995). Japan, on the other hand, has noticed a decrease in both case notifications and mortality rates. The declining rates, however, have been gradually diminishing since the early 1980’s. According to WHO, overall notification cases in Japan have declined at an average of 3. % per year; mortality rates have declined at an average of 4. per year since 1980. New Zealand has also experienced a decline in mortality rates due to TB from 0. 9% to 0. 5% per year since 1980. Underdeveloped or developing areas of the world have seen much higher rates of TB morbidity and mortality, due mainly to the high prevalence of HIV and AIDS.
According to the Global Programme on AIDS of the World Health Organization, almost 90% of all HIV infections have occurred in developing countries. These areas include much of Africa, Asia, Central and South America, and parts of North America. It is estimated that the majority of people infected by both HIV and TB live in sub-Saharan Africa. In 1994, 3. llion of the 5. 6 million individuals infected with both diseases were reported here (Raviglione, 1995). Other estimates of HIV/TB infected individuals are as follows: Table 2: Estimates of HIV/TB co-infection in selected regions Region Number Infected North Africa and the Middle East 23,000 East Asia and the Pacific 20,000 Southeast Asia 1. 15 million Europe and the former Soviet Union 9,000 Western Europe 49,000 North America 80,000 Latin America and the Caribbean 450,000 Tuberculosis Prevalence and Control in Specific Regions Due to the tremendous tuberculosis prevalence around the world, it is crucial that the disease be kept under control.
The current focus is to pay attention to specific examples of how particular countries or geographical sites have dealt with the struggle to control this deadly disease. It should be mentioned that methods for TB control are not specific to a particular country. Many countries have similarities in their treatment programs (i. e. drug use and administration). In some cases, focus will be placed on controlling TB in certain populations. Raviglione, Mario C. ,et al. “Global epidemiolgy of tuberculosis: morbidity and mortality of a worldwide epidemic. ” JAMA. 273:220-6. Jan. 18, 1995. A. In Puerto Rico Puerto Rico, an island located in the Caribbean, had an estimated 1,500 TB cases per 100,000 individuals in 1985.
Various methods were used to try to cure patients and control tuberculosis spread. These include the use of drugs such as isoniazid, rifampin, streptomycin, pyrazinamide, ethambutol, para-aminosalicylic acid, ethionamide, cycloserine, capreomycin and kanamycin (Hunter, 1985). In addition, Hunter (1985) suggested that a rise in the general standard of living along with improvements in housing, nutrition and working conditions is followed by a decline in the incidence of tuberculosis. Hunter, John M. and Arbona, Sonia. “Field Testing along a disease gradient: some geographical dimensions of Tuberculosis in Puerto Rico. ” Social Science and Medicine.
Volume 21, #9, 1985. Page 1023-42. B. In Canada The drugs mentioned above are not the only ones available which are effective in the control of TB. Canada, with a high incidence of TB infection among native Indian populations, has used a different drug in studies to treat newborns of natives. Bacille Calmette-Guerin (BCG) has been used as a vaccine to prevent the development of tuberculosis in these babies. The effectiveness of the drug in protecting newborns has been estimated to be at least 60% (Young, 1986). Although this is not extremely high, when used in conjunction with other treatments, overall effectiveness may be greatly enhanced. Young, T. Kue.
A Case-Control study to evaluate the effectiveness of mass neonatal BCG vaccination among Canadian Indians. ” American Journal of Public Health. Volume 76, July 1986. Page 783-6. C. Underdeveloped Countries Tuberculosis control teams, such as the French-based Association pour la Promotion de la Medecine Preventive (APMP), have been developed specifically to help TB infected children in underdeveloped third world countries. Because so much area in third world countries consist of rural development, vaccines against tuberculosis are often scarce. This occurs because the major hospitals and clinics are found in the more urban developed areas, which are often secluded from the rural world.
As a result, the delivery of vaccines to proper TB infected areas or populations becomes a challenge. However, there is hope. The APMP team was created to give health care to those rural populations (especially children) infected with disease. The four member team consists of the following: a paramedical experienced leader, who administers the one intradermal shot of BCG for tuberculosis and monitors any reactions; a nurse, who explains to the mothers why it is important for the children to return, as well as how to improve family health and nutrition; a driver-mechanic; and a scout who rides ahead to get the village chieftain to assemble the families (Englebardt, 1984).
Each team was efficient in vaccinating hundreds of children per day. Later studies had confirmed that the vaccinated children had developed antibodies against the tuberculosis disease. Englebardt, Stanley L. Saving the Third World’s Children. ” Reader’s Digest. Vol 125, October 1984, pages 136-141. D. In China: China, which created a national tuberculosis control programme in the early 1990’s, has had great success in controlling the infectious disease. The Chinese government proposed that village doctors directly supervise patients (i. e. making sure they took their medication at the right time and with the correct dosage) in order to make sure that they successfully complete their treatment.
In addition, the government significantly reduced the price of tuberculosis medicine, making it affordable for TB infected patients who were financially challenged. By consolidating the purchase of large quantities of TB medicines, the government was able to dramatically reduce the cost of six months’ worth of medicine from as high as $80 to only $13 per person. The outcome of this project yielded some of the most successful results found in the world. Cure rates were found to be 94% by the end of 1991 and 91% by 1993. E. In Tanzania: Tanzania has utilized a strategy similar to China’s in the fight against tuberculosis. Immediate treatment involves the drugs isoniazid, rifampicin, pyrazinamide, and streptomycin. Patients are treated with these drugs each day for two months.
Thereafter, treatments involve only the isoniazid and rifampicin every other day for three months. This treatment has given an increase in cure rate from 43% to 80% in preliminary projects. Global Emergency Alert The World Health Organization estimates that the annual number of new cases of tuberculosis will increase from 7. 5 million in 1990 to 10. 2 million in the year 2000, a global escalation that will produce almost 90 million new cases this decade. Deaths attributable to tuberculosis are likely to rise from 2. 5 million in 1990 to 3. 5 million by the year 2000, making a total of 30 million deaths during the 1990’s (i. e. one quarter of all preventable adult deaths). IT’S A FACT THAT.. TB kills 1. llion people every year. Of these, almost half a million people are co-infected with HIV.
One in three of the global population-about 2 billion people-have latent TB infection, but only about 10% of them will go on to develop the disease. TB is spread by infectious droplets-through coughing, sneezing, or spitting. It thrives in conditions of poverty and overcrowding. A person with active TB can infect an average of 15 people a year. Every year there are about 8 million new TB cases and the poorest and most vulnerable are at highest risk. The disease strikes people during their most productive years. Three out of four deaths occur between the ages of 15 and 54.
Millions of TB deaths could be prevented through the widespread use of DOTS , an inexpensive strategy for the detection and treatment of TB. In 1997 the average treatment success rate worldwide was almost 80%. Unfortunately, less than 25% of people who are sick with TB are treated through the DOTS strategy. A new strain of TB addressed as multi-drug-resistant tuberculosis (MDR-TB) as well as the co-epidemic TB/HIV. Two-thirds of the people living with HIV worldwide are in sub-Saharan Africa and over 90% do not know they are infected. This region accounts for 70% of all co-infections with TB/HIV. strategy. Tuberculosis – Everything U Need To Know (htis Is An Entire Report On