Chapter 15 Infectious Diseases

1. Chapter 15 Infectious Diseases Yang-Qiaohong Guangzhou Universticy OF TCM

2. CONTENTS • TUBERCULOSIS(TB) • TYPHOID FEVER • BACILIARY DYSENTERY • LEPROSY • LEPTOSPROSIS • EPIDEMIC HEMORRHAGIC FEVER • SEXUALLY TRANSMITTED DISEASE

3. Introduction Although the features of pathologic change of infectious diseases is different, its basic pathological changes is the same, belong to the inflammation.

4. 流感 白喉 志贺氏菌痢疾 肾盂肾炎 登革热病 疟疾 斑疹伤寒 淋巴管 小儿麻痹症 黄热病 流行性腮腺炎 水痘 麻疹 狂犬病 雅司病 风疹

5. TUBERCULOSIS(TB) • Tuberculosis(TB) is an infectious disease caused by several different species of mycobacteria. • The lung is his prime target, but any organ may be infected.

6. A. Etiology • Tuberculosis is caused by mycobacterium tuberculosis, which is a slender slightly curved rod-shaped aerobic bacterium. 1~4μm

8. B. Transmission • The main routes of tuberculosis infection are (1) pulmonary, (2) intestinal, (3) tonsillar, (4) cutaneous, and (5) placental ( congenital ). • The disease usually is spread by droplets from a patient with a cavitary lesion that opens into a bronchus.

9. Pathogenesis • Five strains of mycobacterium tuberculosis are recognized ( human, bovine, murine, avian and reptilian ) and infection can occur by inhalation, ingestion (rare following testing of cattle and pasteurization) and inoculation. • The tissue damage associated with tuberculosis is due to the specific reactivity of the immnue system occurring as a result of the presence of the bacterium.This expresses itself in two ways: • (1) Enhanced resistance to infection and more effectivt clearing of the bacterium. • (2) Appearance of hypersensitivity causing most of the damage.

10. 2. Pathogenic substance of mycobacterium tuberculosis ① Lipid: ⅰ Related to pathogenicity, especially glycolipid cord factor: wax D: cause severe allergy→ tissue damage • destroy the membrane of mitochondria • inhibit the emigration of leukocyte • related to the formation of granuloma

11. ⅱ Protect bacillary bodies from digestion of macrophage inhibit bacteria combine with lysosome, the bacteria can survive ⅲ Phosphatide change the macrophage into epithelioid cells in the inflammatory focus

12. ② Polysaccharide lipoarabinomannan inhibit activity of macrophage secreting TNF-α: necrosis IL-10: inhibit cell immune

13. ③ Protein:Heat-shock protein Ag autoinmmune reaction

14. Pathogenesis Cell immunity Type Ⅳ hypersensitivity

16. Three consideration are involved in the pathogenesis of TB (1) Quantity of bacteria (2) Virulence of pathogen (3) Responsiveness of the body sensitivity and immune response

17. Basic pathological changes reactivity quantity virulence features of tissue difference lesions

18. Basic pathological changes • 2. Proliferative changes • (1) Conditions • early stage immunity↓quantity↑ virulence↑ • severe hypersensitivity • (2) Pathologic changes • serous or serofibrinous • early :neutrophils • late :macrophages • (3) Site • lung, serosa, synovialis, meninges • (4) Result absorbed completely development proliferation necrosis

19. Basic pathological changes • 1. Exudative changes characteristic lesion→tubercle Formation of tubercle possesses certain diagnostic feature • (1) Conditions • early stage • immunity↓quantity↑virulence↑ • severe hypersensitivity • (2) Pathologic changes • quantity↓ virulence↓ strong immune reaction

20. Basic pathological changes ① Gross • the size of a millet • clear edge • grayish , semitransparent • yellow with necrosis, somewhat rise on the surface of organ ② LM: typical lesion→tubercle • ( formation based on cell immune ) • Center: caseous necrosis • Surrounding epithelioid cell • Langhans giant cell • Outside lymphocyte • fibroblast

22. Basic pathological changes ① Gross • the size of a millet • clear edge • grayish , semitransparent • yellow with necrosis, somewhat rise on the surface of organ ② LM: typical lesion→tubercle • ( formation based on cell immune ) • Center: caseous necrosis • Surrounding epithelioid cell • Langhans giant cell • Outside lymphocyte • fibroblast

23. Basic pathological changes ⅰ Epithelioid cell • Source: macrophage • phagocytize→M.tuberculosis • Shape: large, abundant cytoplasm, pseudopod • Function: phagocytize, kill mycobacterium ⅱ Langhans giant cell • Source fusion of epithelioid cells • division of nuclei without • cytoplastic division • Shape: multinuclei, floral hoop or • horseshoe-like • Function: phagocytizing and killing mycobacterium

24. Langhans giant cell

25. Epithelioid cell

26. Basic pathological changes • 3. Alterative changes • (1) Conditions: • quantity↑ virulence↑resistence↓ • severe allergy • (2) Lesion: feature→caseous necrosis • ① Gross: slight yellow, homogenous, exquisite creamy • ② LM: red staining, no structure, granular substance • (3) Result • uneasily absorbed • not autolysis, excluded • sometimes: softed, liquefy→spread

27. Basic pathological changes • Three lesions can exist simultaneously • transform one another

30. BACILLARY DYSENSES • Bacillary dysentery is an acute infectious inflammatory disease of the colon,occasionally involving the ileum as well,caused by microorganisms of the genus shigella