1. PHTHISIOLOGY

2. Lecture 5 CLINICAL FORMS OF TUBERCULOSIS: Primary tuberculosis
Secondary tuberculosis

3. Primary TB
The development of clinical TB will occur in 5%-10 % of primary infected persons.
The factors involved in increased risk of developing TB are those interfering directly with host immunity.

4. Factors that facilitate the development of TB disease
Diseases and conditions that weaken immunity, such as malnutrition, alcoholism,
advanced age, HIV/AIDS, diabetes, gastrectomy, chronic renal insufficiency, silicosis, paracoccidioidomycosis, leukemias, solid tumors, immunosuppressive drug
treatments

5. Primary TB in children
3.1 million children under 15 years of age are infected with TB worldwide.
According to the World Health Organization (WHO), children with TB
represent 10 % to 20 % of all TB cases.

6. Primary TB in children The majority of these cases occur in low-
income countries where the prevalence of
HIV/AIDS) is high

7. Primary TB in children
children younger than five years old may develop disseminated TB in the form of miliary disease or tuberculous meningoencephalitis before the TST
result becomes positive.

8. Primary TB in children adopted when pediatric patients have a
A very high index of suspicion must be
adopted when pediatric patients have a
contact history.

9. Primary TB in children Children with asymptomatic infection
usually have a positive TST result but do not have any clinical or radiographic
manifestations. These children may be identified on a routine medical examination.

10. Primary TB in children
TST following standard procedures is an important element for TB diagnosis in children.
Sometimes these patients are identified by a positive TST that may be associated with allergic manifestations such as erythema nodosum and phlyctenular conjunctivitis.

11. Primary TB in children
Erythema nodosum is a toxic allergic erythema with nodular lesions in the skin or under it, 2 to 3 cm large. These lesions are spontaneously painful and very painful under pressure, and are usually located bilaterally in feet and legs. It is usually accompanied by pharyngitis, fever and joint inflammation
and is more frequent in girls over six years.

12. Primary TB in children Primary TB in children
Phlyctenular conjunctivitis is an
allergic keratoconjunctivitis characterized by the presence of small vesicles that
usually evolve to ulcers and resolve without scars. associated to the phlyctenular conjunctivitis are photophobia and an excessive lacrimation
Primary TB in children

13. Primary TB in children
Progression of the primary infectious complex may lead to enlargement of hilar and mediastinal lymph nodes with resultant bronchial collapse. Progressive primary TB may develop when primary focus cavitates and bacteria spread through contiguous bronchi.

14. Primary TB in children
Lymphohematogenous dissemination, especially in young patients, may lead to miliary TB when caseous material reaches the bloodstream from a primary focus or a caseating metastatic focus in the wall of a pulmonary vein Tubercular meningoencephalitis
may also result from hematogenous dissemination.

15. Primary TB in children Tubercular meningoencephalitis
may also result from hematogenous dissemination

16. Primary TB in children Endobronchial tuberculosis
This form of pulmonary TB occurs when the infected lymph nodes erode into a bronchus. Enlargement of lymph nodes may result in signs suggestive of bronchial obstruction or hemidiaphragmatic paralysis.
Dysphagia due to esophageal compression may be observed.

17. Primary TB in children
Vocal cord paralysis may also occur as a result of local nerve compression.
A partial or complete bronchial obstruction can also occur. Usually it is the result of deposition of caseous material within the lumen. Obstructive hyperaeration of a lobar segment or a complete lobe is less common in pediatric patients.

18. Primary TB in children
Cavities, bronchiectasis and bullous emphysema are occasionally seen. Many older children are asymptomatic at he time of diagnosis. In general, however, children are more likely to present with wheezing, cough, fever, and anorexia as part of the symptoms.

19. Primary TB in children
Persistent cough may be indicative of bronchial obstruction, while difficulty in
swallowing may result from esophageal compression. Hoarseness or difficult
breathing may suggest vocal cord paralysis.

20. Primary TB
Adult primary TB is paucibacillary, practically non-contagious, difficult to diagnose.
and of variable severity in seriously
immunodepressed patients

21. Secondary TB
The existence of post-primary TB, also known as secondary TB, means that the
infection can progress after the development of an adequate specific immune response.

22. TB lesions in the upper right lung

23. SIMON’s foci in the left lung

24. This TB episode can develop in two ways:
Secondary TB
This TB episode can develop in two ways:
- by reactivation of the primary focus or
- by inhalation of new bacilli (super infection)

25. Secondary TB
Pulmonary TB is the most common form of post-primary disease

26. Secondary TB
The response to bacillary multiplication provokes caseous necrosis that
eventually blends and progresses to liquefaction.

27. Secondary TB Tubercle bacilli find favorable conditions
for population growth after liquefaction of the caseous necrosis and subsequent cavitation,
and may produce more than 108 bacilli per cavity with a diameter of less than2 cm.
The development of tuberculous cavities in the lung characterizes the postprimary TB

28. Secondary TB infectious material can spread through bronchi,
resulting in the continuous production and elimination of sputum. The natural evolution
of post-primary lesions in immunocompetent persons can lead to dissemination
and death in about 50 % of cases, and to chronicity in about 25 % to 30 %.

29. Secondary TB
Natural cure can also occur in 20 % to 25 % of cases, when the host immune response
is able to re-establish control of the disease

30. TB and HIV In HIV positive persons infected with the
tubercle bacillus, however, 7 % to 10 % will
develop active TB annually.

31. Parenchymal infiltrate in the upper left lung

32. Parenchymal infiltrate in the upper left lung

33. Lung infiltrate and cavitation in the upper lobe of the right lung (x-ray)

34. Lung infiltrate and cavitation in the upper lobe of the right lung (x-ray)

35. Lung infiltrate and cavitation in the upper lobe of the right lung (CT)

36. infiltrate and cavitation and in both upper lobes

37. Miliary TB in adults (chest X-ray)

38. Miliary TB in adults (CT)

39. Pleural involvement with no parenchymal lesion

40. Pleural involvement with upper lobe lung infiltrate

41. Lymph node tuberculosis

42. Cerebral TB: hydrocephaly, hypodense central areas, and atrophic lesions.

43. Erithema nodosum and erithema induratum of Bazin.

44. Tuberculosis and HIV/AIDS
Interactions between M. tuberculosis and HIV infection:
results in the worsening of both pathologies. HIV promotes progression of M. tuberculosis latent infection to disease and, in turn,
M. tuberculosis enhances HIV replication, accelerating the natural evolution of HIV infection

45. X-ray of a patient with HIV co-infection and 427 CD4+ cells/μL ; cavity images in both upper lobes

46. Patient with 23 CD4+ cells/μL: lower and medial lobe opacities with hilar and mediastinal lymph node compromise.

47. AIDS patient with 71 CD4+ cells/μL: hematogenous dissemination of TB
AIDS patient with 71 CD4+ cells/μL: hematogenous dissemination of TB. Figure 17-

48. AIDS and disseminated MDR-TB; CD4+ count of 23 cells/μL.

49. Lymphadenopathy in an AIDS
Aspiration procedure of a cervical lymphadenopathy in an AIDS patient with
disseminated TB. The aspirate had a caseous aspect and was AFB smear microscopy + (10
AFB/field).

50. Lymphadenopathy in an AIDS

51. Kernig’s sign positive in the TB meningitis
Kernig’s sign positive in the TB meningitis. The spinal fluid was positive for M. tuberculosis culture