Tuberculosis - Essay Example

TUBERCULOSIS THEORY OF DEVELOPMENT Tuberculosis Introduction Tuberculosis is a deadly communicable infectious disease caused by a bacteria Mycobacterium tuberculosis. It most commonly affects the lungs and it is known as pulmonary TB. However, it can also affect the central nervous system, lymphatic system, circulatory system, genitourinary system, bones and joints. In certain patients, TB becomes an active disease and in majority of cases affect the lungs. The most common symptoms include a productive, prolonged cough of more than three weeks duration, chest pain, and coughing up blood. The most commom symptoms include fever, chills, night sweats, appetite loss, weight loss, and easy fatigability. Tuberculosis is a world-wide problem but is common in the developing world. Improper hygiene, poverty and a lack of proper medical care all contribute to the increasing incidence of tuberculosis. Since TB is highly contagious, it is easily transmissible between persons and because of this reason all segments of the population are at threat. According to WHO, HIV/AIDS, TB and malaria kill 6 million people every year; nearly 2 million deaths are caused by TB. Though TB is curable statistics says that it kills 5000 people every day. TB especially affects the most vulnerable such as the poorest and malnourished. 2 billion people, equal to one-third of the world’s total population, are infected with TB bacilli, the microbes that cause TB (WHO, 2006). A negligence of public health measures will contribute to an increase in cases. Failure of adequate treatment promotes the development of resistant strains of tuberculosis. Body When the infection spreads out of the lungs, extrapulmonary sites include the central nervous system, lymphatic system in scrofula of the neck, genitourinary system in urogenital tuberculosis, and bones and joints in Potts disease of the spine. An especially serious form is disseminated, or miliary tuberculosis. Extrapulmonary forms are more common in immunosuppressed persons and in young children. Infectious pulmonary TB may co-exist with extrapulmonary TB, which is not contagious (Wikipedia, 2006). There are several types of extrapulmonary TB which are described as follows: Skeletal Tuberculosis: Tuberculous osteomyelitis involves mainly the thoracic and lumbar vertebrae it is also known as Potts disease followed by knee and hip. There is extensive necrosis and bony destruction with compressed fractures and extension to soft tissues. Genital Tract Tuberculosis: TB can occur both in male and female genital tract. In the male, tuberculosis involves prostate and epididymis most often with non-tender induration and infertility. Tuberculous salpingitis and endometritis result from dissemination of tuberculosis to the fallopian tube that leads to granulomatous salpingitis, which can drain into the endometrial cavity and cause a granulomatous endometritis with irregular menstrual bleeding and infertility. Urinary Tract Tuberculosis: A "sterile pyuria" with WBCs present in urine but a negative routine bacterial culture may suggest the diagnosis of renal tuberculosis. Progressive destruction of renal parenchyma occurs if not treated. Drainage to the ureters can lead to inflammation with ureteral stricture. CNS Tuberculosis: A meningeal pattern of spread can occur, and the cerebrospinal fluid typically shows a high protein, low glucose, and lymphocytosis. The base of the brain is often involved, so that various cranial nerve signs may be present. Rarely, a solitary granuloma, or "tuberculoma", may form and manifest with seizures. Gastrointestinal Tuberculosis: This is uncommon today because routine pasteurization of milk has eliminated Mycobacterium bovis infections. However, M. tuberculosis organisms coughed up in sputum may be swallowed into the GI tract. The classic lesions are circumferential ulcerations with stricture of the small intestine. There is a predilection for ileocecal involvement because of the abundant lymphoid tissue and slower rate of passage of lumenal contents. Adrenal Tuberculosis: Spread of tuberculosis to adrenals is usually bilateral, so that both adrenals are markedly enlarged. Destruction of cortex leads to Addisons disease. Scrofula: Tuberculous lymphadenitis of the cervical nodes may produce a mass of firm, matted nodes just under the mandible. There can be chronic draining fistulous tracts to overlying skin. This complication may appear in children, and Mycobacterium scrofulaceum may be cultured. Cardiac Tuberculosis: The pericardium is the usual site for tuberculous infection of heart. The result is a granulomatous pericarditis that can be hemorrhagic. If extensive and chronic, there can be fibrosis with calcification, leading to a constrictive pericarditis (Mini-Tutorials, N.D.). Theory of Development The cause of tuberculosis, Mycobacterium tuberculosis (MTB), is a slow-growing aerobic bacterium that divides every 16 to 20 hours. The M. tuberculosis complex includes 3 other mycobacteria which can cause tuberculosis: M. bovis, M. africanum and M. microti. The first two are very rare causes of disease in immunocompetent people, and M. microti is not usually pathogenic. Other pathogenic mycobacteria are known, such as Mycobacterium avium and M. kansasii; these are part of the group defined as Nontuberculous mycobacteria (NTM). Nontuberculous mycobacteria are mycobacteria that are not part of the M. tuberculosis complex, but cause pulmonary diseases resembling tuberculosis (Wikipedia, 2006). There are two major patterns of disease with TB: Primary tuberculosis: It is seen as an initial infection, usually in children. The initial focus of infection is a small subpleural granuloma accompanied by granulomatous hilar lymph node infection. Collectively, these make up the Ghon complex. In nearly all cases, these granulomas resolve and there is no further spread of the infection. Secondary tuberculosis: It is seen mostly in adults as a reactivation of previous infection, particularly when health status declines. The granulomatous inflammation is much more florid and widespread. Typically, the upper lung lobes are most affected, and cavitation can occur. When resistance to infection is particularly poor, a "miliary" pattern of spread can occur in which there are a myriad of small millet seed (1-3 mm) sized granulomas, either in lung or in other organs (Mini-Tutorials, N.D.). TB is spread by aerosol droplets expelled by people with the active disease of the lungs when they cough, sneeze, speak, or spit. These infectious droplets are 0.5 to 5 µm in diameter and about 40,000 can be produced by a single sneeze. Infection commonly spreads to people with prolonged, frequent, or intense contact with the patient. It is estimated that a person with untreated, active tuberculosis can infect 10-15 other people per year. Others at risk include those from areas where TB is common, patients immunocompromised by conditions such as HIV/AIDS, residents and employees of high-risk congregate settings, health care workers who serve high-risk clients, medically underserved, low-income populations, high-risk racial or ethnic minority populations, children exposed to adults in high-risk categories, and people who inject illicit drugs. Transmission can only occur from people with active—not latent— TB disease. The probability of transmission from one person to another depends upon the quantity of the infectious droplets expelled by the patient, the effectiveness of ventilation, the duration of exposure, and the virulence of the Mycobacterium tuberculosis strain. The most effective way to control infection is therefore isolation of patients with infection. The chain of transmission can be broken by isolating patients with active disease and starting effective anti-tuberculous therapy (Wikipedia, 2006). Conclusion An early detection of TB symptoms should be done by the physician followed by the accurate treatment. Besides, it is essential to educate the patient to prevent its further proliferation. Tuberculosis can be a difficult disease to diagnose. It is mainly due to the difficulty in culturing this slow-growing organism in the laboratory. A complete medical evaluation by a physician generally include a medical history, a chest X-ray, and a physical examination. In some cases tuberculosis radiology is used in the diagnosis of TB. It may also include a tuberculin skin test, a serological test, microbiological smears and cultures. These tests should be made accessable to all people including the most rural areas in the developing world where the disease is more chronic. The antitubercular drugs available for the treatment should be made available and affordable for the most poorest population. The tuberculosis epidemic is worsening worldwide and killed over 2 million people a year over the past several years.  It is a top cause of death among people who are HIV-positive, and is becoming more dangerous with the spread of drug-resistant strains. Although new drug-resistant strains are appearing, TB is treatable and usually curable. It is vital that TB patients faithfully follow their treatment regimen and take all medications as directed, or the disease can recur in a drug-resistant form. Then the treatment and the trauma is even worst for the patient and it might turn out to be fatal. Besides, maintaining good hygiene will help to recover fast from the disease and thereby control spread of the deadly disease. Work Cited Mini-Tutorials, Pathology of Tuberculosis, 16 October 2006, Wikipedia, Tuberculosis Wikimedia Foundation, Inc. 16 October 2006, World Health Organization (WHO), 2006 Tuberculosis Facts, 16 October 2006, Read More