Pulmonary Tuberculosis
Transmission of Tuberculosis: The infectious agent of tuberculosis is carried on airborne droplet which are released from an actively infected person with pulmoanry tuberculosis upon coughing, sneezing, or singing. Ventilation with fresh air is very important, with six or more room air changes an hour being desirable. Covering the mouth and the nose with tissues or a mask, while coughing reduces the number of droplet nuclei put into the air.

Clinical Manifestations: Pulmonary tuberculosis may simulate pneumonia, bronchiectasis, lung abscess, or neoplasm. Many patients may experience fatigue, loss of appetite, weight loss, night sweats, or low grade fevers that persist over weeks to months. This is assciated invariably with the production of mucoid or mucopurulent cough. Hemptysis may be also seen. Shortness of breath is uncommon early in the course of the disease, and usually indicate the presence of significant pleural effusion or extensive disease. Some patients present with the acute onset of productive cough, fever, chills, myalgia and sweating suggestive of influenza.

Tuberculin skin test: The tuberculin skin test, known as PPD, has been the traditional method for demonstrating infection with M. tuberculosis. One tenth of milliliter of PPD is injected into either the dorsal surgface of the arm or the forearm subcutaneously. A pale elevation of the skin should be produced when the injection is done correctly. The test should be read between 48 and 72 hours after injection. The basis of the reading is the presence or absence of induration. The diameter of the induration should be measured transversely and recorded in millimeters.

Who is eligible to take the test? 1) Persons with signs and or symptoms suggestive of current tuberculosis disease. 2) Recent contacts with known tubercuosis cases or persons supected of having tuberculosis. 3) Persons with abnormal chest radiographs compatible with past tuberculosis. 4) Persons with medical conditions that increase the risk of tuberculosis (silicosis, gastrectomy, diabetes, immunosuppressive therapy, renal failure, etc.). 5) Persons with HIV infection. 6) Groups at high risk of recent infection with M. tuberculosis such as immigrants from Asia, Africa, Latin America, some inner city and skid row population; presonnels and long term residents of hospitals and nursing homes.