10. Epidemiology WHO estimates that one third of the world’s population are infected with M. tuberculosis. Tuberculosis is especially prevalent in populations undergoing the stresses of poor nutrition, over-crowding, inadequate health care, and displacement.
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14. Spread of droplet nuclei from one individual to another. CDC. After droplet nuclei are inhaled, the bacteria are nonspecifically taken up by alveolar macrophages. However, the macrophages are not activated and are unable to destroy the intracellular organisms.
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17. Evidence suggests that differences in tuberculosis attack rates result from differences in socioeconomic status and living conditions rather than racial factors.
25. ghon complex in lung,gross. Note the subpleural granuloma at the right along with the granuloma in the hilar lymph node, typical findings for the Ghon complex of primary TB.
26. Ghon complex in lung,closer view,gross. On closer inspection,caseous tan necrotic tissue is seen to constitute the granulomas in this gross appearance of a Ghon complex. Most patients with primary TB are asymptomatic, and the granulomas resolve
28. Cavitary tuberculosis in lung, closer view,gross. The caseous necrosis is extensive, and cavitation is prominent. Such patients can be highly contagious
29. Miliary tuberculosis in lung, gross. The small millet seed sized granulomas in this lung are typical for miliary Tuberculosis
30. Miliary tuberculosis in lung, closer view,gross. Miliary tuberculosis, as seen here, typically occurs when resistance to mycobacterial infection is poor.
72. 18 year-old woman presented with a several month history of progressive swelling of the left side of her neck. Biopsy of the neck node was positive for acid-fast bacilli