TUBERCULOSIS

 

INTRODUCTION: Tuberculosis (TB), an infectious disease primarily affecting the lung parenchyma, is most often caused by Mycobacterium tuberculosis. It may spread to almost any part of the body, including the meninges, kidney, bones, and lymph nodes. The initial infection usually occurs 2 to 10 weeks after exposure. The patient may then develop active disease because of a compromised or inadequate immune system response. Immunity  The active process may be prolonged and characterized by long remissions when the disease is arrested, only to be followed by periods of renewed activity. TB is a worldwide public health problem that is closely associated with poverty, malnutrition, overcrowding, substandard housing, and inadequate health care. Mulnutrition

TRANSMISSION OF TUBERCULOSIS: TB is transmitted when a person with active pulmonary disease expels the organisms. A susceptible person inhales the droplets and becomes infected. Bacteria are transmitted to the alveoli and multiply. An inflammatory reaction results in exudate in the alveoli and bronchopneumonia, granulomas, and fibrous tissue. Bronchopneumonia  Onset is usually insidious.

RISK FACTORS: Close contact with someone who has active TB. Immunocompromised status such as the elderly, cancer patients, use of corticosteroid therapy, and HIV. Injection drug use and alcoholism. People lacking adequate health care such as, homeless or impoverished, minorities, children, and young adults. Preexisting medical conditions, including diabetes, chronic renal failure, silicosis, and malnourishment. Immigrants from countries with a high incidence of TB. Institutionalization for example, long-term care facilities, prisons. Living in overcrowded, substandard housing. Occupation such as, health care workers, particularly those performing high-risk activities.

CLINICAL MANIFESTATIONS: Low-grade fever, cough, night sweats, fatigue, and weight loss. Nonproductive cough, which may progress to mucopurulent sputum with hemoptysis.

ASSESSMENT AND DIAGNOSTIC METHODS: TB skin test (Mantoux test); Chest x-ray; Acid-fast bacillus smear; Sputum culture.

MEDICAL MANAGEMENT: Pulmonary TB is treated primarily with antituberculosis agents for 6 to 12 months. A prolonged treatment duration is necessary to ensure eradication of the organisms and to prevent relapse.

PHARMACOLOGIC THERAPY: First-line medications: isoniazid or INH, rifampin, pyrazinamide, and ethambutol, daily for 8 weeks and continuing for up to 4 to 7 months.

Second-line medications: capreomycin, ethionamide, para-aminosalicylate sodium, and cycloserine. Vitamin B (pyridoxine) usually administered with INH to prevent peripheral neuritis.

RELATED;

1.  PNEUMONIA  

2.  PULMONARY EMBOLISM 

3.  MEDICAL CONDITIONS

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