Tuberculosis

I- TB Primary infection:

– More frequent latent forms (normal clinical examination and radiological); isolated corner of the UDR to tuberculin.

– Three classic situations: erythema nodosum; typhobacillose Landouzy (FT simulates high plateau with fever, diarrhea and SPM); keratoconjunctivitis phlyctenular

– IDR: 10 IU (0.1 ml) of tuberculin intradermal injection. The turn is defined as a ≥ 5 mm induration in an unvaccinated;induration of more than 10 mm from an IDR performed within 2 years. A ≥ 10mm IDR sign a positive test.

– Anergy (TST): sarcoidosis, hematologic malignancy, acute viral diseases.

– False negatives (IDR): miliary, pleurisy.

– Sequels bronchectasiques (middle lobe syndrome or Brock) with hemoptysis.

– The risk of developing pulmonary tuberculosis is 10% and is highest in the 2 years following the IPO.

– Chest X-ray: ADP ipsilateral, latérotrachéale, international (trach) or bronchial hilar.

– BK search (especially cultural) positive in 25% of cases if normal radiography; positive in 50% of cases when abnormal radiography

– Treatment of patent PIT -> 2RHZ / 4RH; treatment of latent PIT -> isoniazid (INH) for 6 months.

II- common pulmonary tuberculosis:

– It is either reinfection endogenously (PIT untreated) or from reinfection (exogenous)

– In acute pulmonary resistance to antibiotics well conducted should suggest this diagnosis.

– Prevalence and the apex in the apical segment of the lower lobe (Fowler lobe)

– Collection: concerns the morning sputum 3 days in a row (or by gastric intubation). If bronchial secretions collected by endoscopy must be collected sputum (or gastric lavage) after 3 days of endoscopy.

– If culture, the average time to positivity is 21 to 28 days (doubling time = 20h). Negative if no culture after two months. The susceptibility testing is essential.

– Blood tests: no leukocytosis (see leukoneutropenia); ESR is often greatly increased (this is followed by element).

– Tuberculous Caves: these are cavities located within the parenchyma, resulting in the evacuation of the bronchi caseum softened. They may be the cause of hemoptysis, of Aspergillus transplants. Sequel -> stenosis of the bronchus drainage.

– The contagiousness of smear subjects usually disappears within 15 days to a month; the positivity of the cultures after 3 months should be investigated resistance of the bacillus or poor adherence to treatment.

– Radiation monitoring every 6 months for 2 years; then every 5 years

– Recurrence imposes the search for a new contamination

– Relapse is defined as the occurrence of a new TP after the end of treatment and within 3 years.

III- Miliary tuberculosis:

– Due to hematogenous spread BK; realizes the chest radiograph of micronodular images millet grains (sometimes blurring frosted glass)

– Functional signs: tachypnea, cough, nausea, diarrhea, abdominal pain misleading.

– Alteration of the general state subfebrile then at 39-40 ° C fever tray; the undissociated pulse. SPM can

– The IDR is often negative

– Cholestasis is almost constant

– Value of the liver or bone marrow biopsy

– Systematic Review: FO (tubers Bouchut), PL (lymphocytic meningitis), ECG and echocardiography (pericarditis);ECBU.

– Cold Miliaria afebrile old man

– Miliaria bronchogenic: larger nodules, systematic localization, radiological association with the cause (cave, ADP)

IV- Treatment:

PHARMACOLOGY – DOSAGE:

Isoniazid (INH):

* Complete Digestive absorption if taken on an empty stomach

* Crosses the placenta and excreted in milk

* Especially effective vis-à-vis the extracellular BK active multiplication (cave) and intracellular.

* Germ

* Hepatic metabolism; acetylation inactivates its action (fast and slow acetylators)

* Dosage: 5 mg / kg / day

* Avoid the combination with enzyme inducers (except rifampicin)

Rifampicin:

* Complete absorption if taken on an empty stomach

* It crosses the placenta and -> milk.

* Active liver metabolite on BK

* It is effective on all people of BK (bactericidal)

* Enzyme inducer: AVK; oral contraceptives; digitalis; corticoid

* Phenobarbital and other inducers increase its toxicity.

* Dosage: 10mg / kg / day

Pyrazinamide:

* Excellent Diffusion

* Powerful elective activity on intracellular BK

* Germ.

* Urinary Excretion

* Dosage: 30 mg / kg / day

Other:

Ethambutol:

* Germ

* Acts on the extracellular BK active multiplication (cave +++).

* Dosage: 20mg / kg / day; 1mg / d IM

* Elimination mainly by the kidney

Streptomycin:

* Bacteriostatic

* Active on extracellular BK

* Elimination active form in urine

* Dosage: 20 mg / kg / day

SIDE EFFECTS:

* Isoniazid -> hepatic cytolysis; peripheral neuropathy

* Rifampicin -> Hepatotoxicity; leukopenia; risk of failure of oral contraception

* Pyrazinamide -> Hepatotoxicity; hyperuricemia

* Ethambutol -> Optic neuritis

# Presentations:

– Rifinah®: 150 mg isoniazid and rifampicin 300 mg (weight> 50kg -> 2 cp / d)

– Pirilène®: 500 mg of pyrazinamide (weight> 50kg -> 4 cp / d)

Note: other anti-BK -> kanamycin, cycloserine, ethionamide. Pyrazinamide is against indicated during pregnancy.

# Balances:

– Pretreatment assessment: liver test; renal function; serum uric acid; ophthalmological examination (if ethambutol);audiogram if streptomycin

– Biological Monitoring: Liver function tests in the 10th, 20th and 30th days

– Review monthly ophthalmic if ethambutol treatment

– Efficiency: radiography (1 month, 2 months, 6 months, 12 and 24 months); BK every month until negative cultures

# Directions:

– Latent PIT -> secondary chemoprophylaxis (INH monotherapy for 6 months or RZ combination for 2 months)

– License PIT -> 2RHZ / 4RH

– Common Pulmonary tuberculosis -> 2ERHZ / 4RH

– Miliary tuberculosis -> 2ERHZ / 4RH

– Bone shape -> need for treatment for 12 months

– Corticosteroid therapy may be warranted in case of pericarditis or tuberculous meningitis

# Special cases:

– Hepatic impairment -> INH strict dose (+ B1B6 lives); rifampicin ½ dose (weekly transaminase); pyrazinamide against specified

– If transaminase elevation: no change if <6N; if> 6N: stop (Z) and decrease of ½ of INH and rifampicin at the same dose

– If severe hepatitis with signs of IHCaire -> stopping all hepatotoxic drugs and prudent reintroduction (rifampicin and INH) but against pyrazinamide said.

– Renal impairment: pyrazinamide is against indicated unless strictly necessary

– Pregnancy -> combination therapy with 3ERH / 6RH

– HIV -> 9 months of treatment

# Vaccination:

– BCG is a live vaccine (Mycobacterium bovis attenuated by iterative transplanting)

– An IDR 10 U should be done 4 to 6 months after vaccination; when the reaction is negative (<5mm), it checks for transient anergisante disease (influenza, measles …); there is no cause of error is repeated vaccination

– BCG gives a neighboring conversion of 90% and the duration of protection is of the order of 15; the coverage rate is 60%; it effectively prevents blood-borne releases (miliary) and to a lesser degree violations neuromeningeal.

# Primary chemoprophylaxis:

– Presumptive treatment before the TST fragile subjects (children under 5 not vaccinated with BCG; about HIV) in contact with an infectious case.

– INH for 3 months, extended for 3 additional months if the IDR is positive or by rifampicin-pyrazinamide combination.