Tuberculosis

1. Tuberculosis .

2. TUBERCULOSIS Tuberculosis is a chronic infectious and communicable granulomatous disease caused by the Mycobacterium tuberculosis. Tuberculosis most commonly affects the lungs (PTB) but can also affect any part of the body for example- the central nervous system, the lymphatic system, the circulatory system, the genitourinary system, bones, joints and even the skin.

3. Natural history of the tuberculosis • Causative agent-Mycobacterium tuberculosis (MTB), is a slow-growing aerobic bacterium that divides every 16 to 20 hours; this is extremely slow compared to other bacteria, which have division times measured in minutes. • Source of infection-human and bovine. The most common source of infection is human, whose sputum is positive for tubercle bacilli and who has either receive no treatment or not been treated fully. The bovine source of infection is usually infected milk. • Faeces,urine,pus,pleural and peritoneal fluids, gastric contents in extra pulmonary tuberculosis

4. Communicability: Patients are infective as long as they remain untreated, effective anti-microbial treatment reduces infectivity by 90% within 48 hours. Host factors: a) Age: Tuberculosis affects all ages. b) Sex: More common in males. Incubation period: weeks, months or even years

5. Transmission TB is spread by droplets expelled by people with the active disease of the lungs when they cough, sneeze, speak, kiss, spit The chain of transmission can be broken by isolating patients with active disease and starting effective anti-tuberculous therapy. ( transplancental, ingestion, inoculation,)

6. Risk factors Smoking more than 20 cigarettes a day also increases the risk of TB by two- to four-times. Immunocompromise patient for example, AIDS, those undergoing chemotherapy, The risk of TB increases with the frequency of contact with people who have the disease, with crowded or unsanitary living conditions and with poor nutrition. Others at risk include those from areas where TB is common, health care workers who serve high-risk clients, medically under served, low-income population, children exposed to adults in high-risk categories

7. Symptoms A productive, prolonged cough of more than three weeks duration, chest pain and coughing up blood. Systemic symptoms include fever, chills, night sweats, appetite loss, weight loss and anemia, easily fatigued. • Extra pulmonary forms are more common in immunosuppressed persons and in young children.

8. Diagnosis A medical history a chest X-ray A physical examination Sputum for AFB – 3 specimen (morning) Tuberculin skin test/Mantoux

9. chest X-ray shows consolidation/opacity, cavity , hilarlymphadenopathy.

10. Chest X-ray pleural effusion , pneumothorax

11. Mantoux test The Mantoux test is carried out by injecting intradermally on the flexor surface of the forearm 1 Tuberculin Unit of PPD in 0.1ml. The result of the test is read after 72 hours. Reaction exceeding 10 mm (induration )are considered positive. A positive reaction indicates that the person is infected with M. tuberculosis, it does not prove that the person is suffering from the disease.

13. Treatment • Anti-tuberculosis drugs: It should be highly effective, free from side effects, easy to administer, and reasonably cheap. The currently used drugs may be classified into two groups: bactericidal and bacteriostatic. • Bactericidal drugs • Rifampicin: 10 mg/kg body weight. Side effect-red urine, hepatitis • Isoniazide (INH): single daily dose of 5 mg/kg body weight . Side effect hepatis & peripheral neuropathy • Streptomycin: the daily dose is 15 gm in a single dose. Side effect - ototoxicity • Pyrazinamide: 25 mg/kg body Side effect - joint pains & hepatitis

14. Bacteriostatic drugs • Ethambutol: 15 mg/kg body weight in 2-3 doses per day. Its major side effect is optic neuritis. • Thioacetazone: the usual adult dose is 2 mg/kg body weight. Side effects include GI disturbance, blurring of vision, hemolytic anemia and urticaria.

15. TREATMENT First Line Drugs: • Rifampicin • Isoniazid • Ethambutol • Streptomycin • Pyrazinamide Second Line Treatment: • Ethionamide • Ciprofloxacin/Ofloxacin • Cycloserine • Kanamycin • Para-aminosalicylic acid.

16. DOTS (Directly observed treatment, short course chemotherapy) Patient swallows the medications under the watchful eye of a reliable person – doctors, nurse, health worker, community volunteer for the duration of 6-9 months. By this method 100% cure of the patients is expected, if the patient takes the drugs without fail. It is free of cost in all health facilities working for the National TB control program.

17. Two-phase chemotherapy First phase or initial phase: During this intensive phase, three or more drugs are combined to kill off as many bacilli as possible. The drug include INH, Rifampicin, pyrazinamide and streptomycin or ethambutol for a period of 2 months The second or continuation phase: aimed to kill the persisting bacilli, followed by 2 drugs in continuation phase, INH and rifampicin or thioacetazone, given daily for 6 months.

18. Treatment H – Isoniazide R – Rifampicin S – Streptomycin Z – Pyrazinamide E – Ethambutol T – Thiacetazone

19. Multi drug resistance • Isoniazid : REZ for 9 – 12 months • Rifampicin : HE for 18 months • If both HR : EZ +quinolone for 9 -12 months +inj. Streptomycin or amikacin for first 4 – 6 months

20. Complications • pleural Effusion • Pneumothorax • Empyema • Miliary TB • Lung Abscess

21. Prevention • A BCG vaccination: BCG is the only widely used live bacterial vaccine. It consists of living bacteria derived from an attenuated bovine strain of tubercle bacilli. • for protection of infants and young children from serious forms of tuberculosis, such as TB meningitis and miliary TB • for routine use at birth in countries with high TB prevalence • protection from serious form of TB doesn’t extend to adults • given immediately after birth under EPI • Dosage: 0.1 mg given intradermally