tb

Question 1

TUBERCULOSIS

Answer 1

Tuberculosis is a chronic infectious disease caused by Mycobacterium
tuberculosis

Question 2

ETIOLOGY

Answer 2

M. tuberculosis, (the most important cause in
humans), M. bovis, M. africanum, M. microti and M.Canetti

Question 3

MODE OF TRANSMISSION
4

Answer 3

• Inhalation: - pulmonary tuberculosis
  o Infectious droplet nuclei can be spread into the air by:
  ▪ Coughing (single coughing Can produce 3000 droplet nuclei)
  ▪ Talking
  ▪ Sneezing
  ▪ Spitting and singing
  o Most important source is smear positive coughing adult
• Ingestion (raw milk): - intestinal Tuberculosis
• Wound contamination: - cutaneous tuberculosis
• Hematological spread form primary Tuberculosis focus

Question 4

tb classification based on timr of infectionn

Answer 4

• Primary infection occurs in persons without previous exposure to tubercle
  bacilli

Question 5

A localized granulomatous inflammatory process occurs within the lung and this
is called

Answer 5

the PRIMARY (GHON) FOCUS

Question 6

The Ghon focus with associated tuberculous lymphangitis and involvement of
the regional lymph nodes is called

Answer 6

the primary (Ghon) complex

Question 7

…………… percent of persons infected with M. Tuberculosis, the immune system either
kills the bacilli or perhaps more often, keeps them suppressed (silent focus)
resulting in a latent TB infection (LTBI).

Answer 7

90-95

Question 8

Active TB disease may arise from

Answer 8

o progression of the primary lesion after infection
o from endogenous reactivation of latent foci, which remained dormant
since the initial infection
o from exogenous re-infection

Question 9

CLINICAL STAGES

Answer 9

exposure, infection, and disease

Question 10

EXPOSURE MEANS

Answer 10

• A child has had significant contact with an adult or adolescent with infectious
  tuberculosis but lacks proof of infection
• In this stage, the tuberculin skin test (TST) or interferon-γ release assay (IGRA)
  result is negative
• The chest radiograph and physical examination is normal
• The child lacks signs or symptoms of disease
• However, the child may be infected and develop TB disease rapidly, since there
  may not have been enough time for the TST or IGRA to turn positive

Question 11

TUBERCULOSIS INFECTION (TBI):

Answer 11

• It occurs when the individual inhales droplet nuclei containing M. tuberculosis,
  which survive intracellularly within the lung and associated lymphoid tissue
• The hallmark of TBI is a positive TST or IGRA result
• In this stage the child has no signs or symptoms
• A normal physical examination, and the chest radiograph is either normal or
  reveals only granuloma or calcifications in the lung parenchyma

Question 12

DISEASE

Answer 12

• occurs when signs or symptoms or radiographic manifestations caused by M.
  tuberculosis become apparent
• Not all infected individuals have the same risk of developing disease
• An immunocompetent adult with untreated TBI has approximately a 5–10%
  lifetime risk of developing disease An infected child <1 yr old has a 40% chance
  of developing TB disease within 9 months

Question 13

RISK FACTORS FOR TUBERCULOSIS INFECTION

Answer 13

• Children exposed to high-risk adults
• Foreign-born persons from high-prevalence countries
• Homeless persons
• Persons who inject drugs
• Present and former residents or employees of correctional institutions,
  homeless shelters, and nursing homes
• Healthcare workers caring for high-risk patients (if infection control is not
  adequate

Question 14

RISK FACTORS FOR PROGRESSION OF TUBERCULOSIS INFECTION TO
TUBERCULOSIS DISEASE

Answer 14

• Infants and children ≤4 yr old, especially those <2 yr old
• Adolescents and young adults
• Persons co-infected with human immunodeficiency virus
• Persons with skin test conversion in the past 1-2 yr
• Persons who are immunocompromised, especially in cases of malignancy and
  solid-organ transplantation,
• Immunosuppressive medical treatments including anti–tumor necrosis factor
  therapies, diabetes mellitus, chronic renal failure, silicosis, and malnutrition

Question 15

RISK FACTORS FOR DRUG-RESISTANT TUBERCULOSIS

Answer 15

• Personal or contact history of treatment for tuberculosis
• Contacts of patients with drug-resistant tuberculosis
• Birth or residence in a country with a high rate of drug resistance
• Poor response to standard therapy
• Positive sputum smears (acid-fast bacilli) or culture ≥2 months after initiating
  appropriate therapy.

Question 16

Time between initial infection and clinically apparent disease:
in every system
renal bone pulm. LN cns

Answer 16

• Disseminated and meningeal tuberculosis are early manifestations (2–6 months)
• Significant lymph node or endobronchial tuberculosis (within 3–9 months)
• Lesions of the bones and joints take several years to develop
• Renal lesions (decades after infection)

Question 17

CLINICAL MANIFESTATIONS of primary pulm tb

Answer 17

Nonproductive cough and mild dyspnea are the most common symptom

Question 18

pathophysiology of the clinical manifestations

Answer 18

As delayed-type hypersensitivity develops, the hilar lymph nodes continue to
enlarge in some children, especially infants, compressing the regional bronchus
and causing obstruction.

Question 19

clinical manifestation of PROGRESSIVE PRIMARY PULMONARY DISEASE

Answer 19

(High fever, severe cough with sputum
production, weight loss, and night sweat )

• A rare but serious complication of tuberculosis in a child occurs when the
  primary focus enlarges steadily and develops a large caseous center
• Liquefaction can cause formation of a primary cavity associated with large
  numbers of tubercle bacilli.

Question 20

REACTIVATION TUBERCULOSIS types based in site

Answer 20

pulmonary
non pulmonary

Question 21

REACTIVATION TUBERCULOSIS clinical mani

Answer 21

fever, anorexia,
malaise, weight loss, night sweats, productive cough, hemoptysis, and chest pain

Question 22

PULMONARY TUBERCULOSIS define and symptoms

Answer 22

o Persistent cough for two or more weeks, (cough of any duration for HIV positives)
o Fever for more than 2 weeks
o Night sweats
o Unexplained weight loss

to any bacteriologically confirmed or clinically diagnosed case of TB
involving the lung parenchyma or the tracheobronchial tree.