Tuberculosis

Question 1

Definition of Tuberculosis

Answer 1

communicable infectious disease caused by Mycobacterium tuberculosis which produces silent, latent infection or a progressive active disease, regarded as leading infectious killer disease

Question 2

Diagnosis of TB in children

Answer 2

• Tuberculin Skin Test (TST)
• Chest X-ray
• microscopy
• culture of sputum, fluid, and tissue samples

Question 3

Cause of TB

Answer 3

Mycobacterium tuberculosis bacilli

Question 4

Transmission:

Answer 4

Spread through micro-sized droplet nuclei during coughing and sneezing

Question 5

risk of infection with cavitary and laryngeal TB

Answer 5

• Cavitary pulmonary TB-Patients with cough can infect one person per month until treated
• Laryngeal TB-Even talking can spread M. tuberculosis, increasing transmission risk

Question 6

Immune System Role

Answer 6

Tasked with recognizing and suppressing M. tuberculosis

Question 7

Key Cell Types

Answer 7

Macrophages
CD4 T-Lymphocytes (Helper lymphocytes)
CD8 T-Lymphocytes (Cytotoxic/suppressor lymphocytes)

Question 8

Macrophages’ Function

Answer 8

• Present antigens
• activate interleukins
• secrete interferons
• and activate other macrophages to destroy M. tuberculosis.

Question 9

Cytotoxic T-Lymphocytes

Answer 9

Responsible for destroying cells harboring Mycobacterium

Question 10

Immuno-regulatory Role of T-Lymphocytes

Answer 10

T-Lymphocytes contribute to the host’s resistance to developing infection.

Question 11

HIV Impact

Answer 11

In HIV, destruction of CD4 T-Lymphocytes increases the risk of developing active TB disease

Question 12

Risk factors for TB


Answer 12

• Previous exposure to pulmonary TB case
• History of previous TB
• Immune status
• Close contacts to TB patients
• Race and ethnicity
• Age, gender, and occupation
• HIV status
• Location and place of birth
• Urban vs rural areas
• Underprivileged patients
• Recalcitrant patients
• History of working at mines
• History of diabetes, smoking, alcoholism, malnutrition
• Prolonged treatment with steroids

Question 13

Diagnosis of TB


Answer 13

• Sputum smear microscopy
• microbiology culture and sensitivity
• molecular assays like GeneXPert, chest X-ray
• clinical presentation evaluation

Question 14

M. tuberculosis


Answer 14

Bacilli causing TB, transmitted from person to person through microsize droplet nuclei dispersed through coughing and sneezing

Question 15

Risk factors for TB in children


Answer 15

• History of recent contact with TB case
• Age
• Time since exposure/infection
• Immune status

Question 16

Monitoring parameters for adverse drug reactions


Answer 16

• Adherence to therapy
• Adverse drug reactions specific for each medication
• Smear test q 1-2 weeks to be negative in ~ 2 weeks
• Sputum culture q 2-3 months to be negative at 2 months
• Liver function tests
• Serum creatinine
• Eye examinations

Question 17

Management of TB: 1st Line Medicine


Answer 17

• Isoniazid (H)
• Rifampicin (R)
• Pyrazinamide (Z)
• Ethambutol (E)
• Streptomycin (S)

Question 18

Risk factors for TB


Answer 18

• Prolonged treatment with steroids
• History of recent contact with TB case
• Age i.e. the very young < 3 years
• Time since exposure/infection (TB disease likely to develop within 1 year)
• Immune status – increased risk of TB disease if have HIV infection, malnutrition, immune suppressive therapy e.g. chemotherapy, corticosteroids

Question 19

Goal of management of TB


Answer 19

1. Prompt resolution of signs and symptoms of disease
2. Cure the patients (in a short period of time)
3. Restore quality of life
4. Prevent morbidity and mortality
5. Prevent relapse and development of drug resistance
6. Prevent TB transmission to others

Question 20

Prophylaxis for TB patients


Answer 20

Children: Isoniazid
HIV positive children and adults: Cotrimoxazole – daily dosing

Question 21

Fixed Combination First-line Anti-TB Agents in Paediatrics

Answer 21

Recommended regimen for TB
* New patients < 30 kg: 2HRZE/4HR
* New patients ≥ 30 kg: 2HRZE/4HRE
* Retreatment: 2HRZES/1HRZE/5HRE

Question 22

Non-Pharmacological management of TB

Answer 22

1. Prevention of spread of disease through isolation and infection control guidelines
2. Contact investigation/tracing
3. Replenishment to normal weight

Question 23

Clinical presetation

Answer 23

• Generalized symptoms:
  – Loss of appetite
  – Weight loss
  – Malaise
  – Fever ≥ 2 weeks
  – Night sweats
• As disease progresses:
  – Persistent cough – productive cough ≥ 2 weeks
  – Shortness of breath, chest pains or hemoptysis

Question 24

Physical exams and radiological findings consistent with TB

Answer 24

• Physical examination: lungs
• Abnormal with crepitations
• CXR – radiographic findings:
  – Patchy or nodular infiltrate in apical areas of upper
  lobe or superior segment of lower lobes
  – Cavitation ∓ fluid (as disease progresses)

Question 25

Clinical presentation: Paediatric

Answer 25

* Weight loss or failure to thrive * Enlargement of lymph nodes (> 1 x 1 cm) * Cough for ≥ 2 weeks * Fever for ≥ 2 weeks * Fatigue, reduced playfulness * Profuse night sweats ≥ 2 weeks * Physical examination – Cough, wheezing, respiratory distress – Haemoptysis – rare in children w/ PTB