儿科学教学课件：Tuberculosis in children

1、 Tuberculosis in children Pediatrics Etiology: Tubercle bacillus Oder Actinomycetales Family mycobacteriaceae Genus Mycobacterium(M.) Species M. tuberculosis M. bovis Non-TB M. Characteristics vAcid-fastness vSlow-growing vUnusual resistance vMulti-Drug Resistance strain(MDR) Etiology v Tubercle bac

2、illi Mycobacterium tuberculosis, Mycobacterium bovis, v Non-spore forming, nonmotile, pleomorphic, obligate aerobes, weakly G+ curved rods, 2-4m long v Lipid-rich cell wall v Acid fast bacilli v Grow slowly Acid fast stain Grow slowly vThe generation time: 12-24hrs vOn solid culture media: 3-6w, and

3、 susceptibility: another 4w vOn selective liquid media with radio labeled nutrients:1-3w, susceptibility: 3-5d vNucleic acid amplification (NAA): several hours Selective resistant 109 drug-susceptible tubercle bacilli XXXXXXXXXXXXXXX Natural resistant XXXXXXXXXXXXXXX Isoniazid X XXXXXXXXXXXXXXX Mult

4、iply Natural resistant XXXXXXXXXXXXX XXXXXXXXXXXXX Rifampin X Multiply Isoniazid resist Isoniazid and Rifampin resist 108 Epidemiology vSource of infection vRoute of transmission vHigh-risk population Source of infection Open Pulmonary Tuberculosis with v acid-fast smear of sputum(+) v copious produ

5、ction of thin sputum v severe and forceful cough v extensive upper lobe infiltrate or cavity Young children with TB rarely infect others High-risk population vEnvironmental factors: socioeconomic status overcrowding poor nutrition inadequate health care vGenetic background: twin racial difference HL

6、A BW35 Route of transmission vBy respiratory tract: airbone mucus droplet nuclei (10 m). contaminated dust vBy alimentary tract raw milk contaminated food vBy others: (Placenta,skin) Transmission rarely occurs by direct contact with an infected discharge or contaminated fomite! TB-specific cellular

7、immunity but incomplete resistance Acquired immunity Infection or not: Determining factors vVirulence of the TB strain vInoculation vThe hypersensitivity of the individual tissues vNutritional or social status vImmunologic status vGenetic background Acquired specific immunity Immunity : a double-edg

8、e sword Tuberculin test：principle & method vBased on delayed type hypersensitivity( type IV) vTwo antigen preparations: Old tuberculin, OT Protein purified derivative, PPD vIntradermal injection of 0.1ml containing 5 tuberculin units of PPD (Mantoux test) Tuberculin skin test: result evaluation vThe

9、 amount of induration should be measured by a trained person 4872hours after administration vIntensity: or : =20mm strong-positive + : blister,ulcer,lymphangitis,double rings What does it mean: Positive result vPrevious infection with TB vPrevious vaccination with BCG vActive tuberculosis = 15mm con

10、version occurring within 2 years What does it mean: Negative result vNot infected with TB vFalse-negative : incubation period immunosuppression or immunodeficiency technical error or improper reagents Prevention of TB vAvoiding contact with those with open pulmonary tuberculosis vBCG (Bacillus Calme

11、tte-Guerin) vaccination vChemoprophylaxis Spreading of M.tuberculosis Initial focus (local infection at the portal of entry) Draining lymphatic vessles Regional lymph nodes Blood Other tissues of the body Primary Pulmonary Tuberculosis Pediatrics Primary pulmonary tuberculosis: Clinical types Initia

12、l focus vPrimary complex lymphangitis Lymphadenitis v Bronchial lymph node tuberculosis Primary pulmonary tuberculosis: Clinical manifestation vSurprisingly thin (subclinical) vInfants more likely to develop signs and symptoms vNonproductive cough and mild dyspnea as the most common symptoms Primary

13、 pulmonary tuberculosis: Less common symptoms vSystemic complaints fever, night sweats, failure-to-thrive, anorexia, etc. vBronchial irritation or obstruction localized wheezing Diagnosis vHistory vClinical manifestation vTuberculin test vX-Ray vIsolation of M. tuberculosis vFiberoptic bronchoscopy

14、Prognosis vImprove or dissolve v Completely resolution v Induration v Calcification v Local progress v Exacerbation absorption fibrosis calcification Improve Progress expansion, PE EBTB +emphysema +atelectasis Deteriorate bronchial primary caseous miliary metastasis cavity Pneumonia pneumonia Primar

15、y complex TB of Bronchial lymph node The development of primary complex Tuberculous meningitis Pediatrics Tuberculous meningitis: introduction vMost common in children of 6mo4yr vUsually develops during the lymphohematogenous dissemination of the primary infection vHigh mortality and high morbidity

16、Clinical manifestation vStage 1: Prodromal stage vStage 2: Transitional stage vStage 3: Terminal stage Stage 1: Prodromal stage vLasts 12wk vNonspecific symptoms: character alteration, fever, headache, malaise, irritability, sleepy vFocal neurologic signs absent Stage 2: Transitional stage vIncrease

17、d intracranial pressure: headache, projectile vomiting, papilledema vMeningeal irritation: nuchal rigidity, Kernigs sign, Brudzinskis sign vToxic appearance: fever, anorexia, nausea vOthers: cranial nerve palsies, convulsion Stage 3: Terminal stage v13wk vExacerbation of neurologic symptoms vVery th

18、in with scaphoid abdomen vElectrolyte imbalance SIADH （syndrome of inappropriate antidiuretic hormone secretion） Cerebral salt losing syndrome Diagnosis vThe earlier, the better. vCautiousness vLumber tap and CSF examination Typical CSF picture vPressure vAppearance ground-glass vCell counts 5050010

19、6/L, L. predominates vProtein vGlucose 40mg/dl，or CSF/blood 1000 0200 v predominate L PMN L vProtein or - vGlucose - vChloride - vPathogens Treatment vAntituberculosis therapy: vCorticosteroids vSymptomatic management vSupportive care Combination chemotherapy intensive treatment consolidation treatment Directly Observed Therapy Shortcouse(DOTS) Treatment v Principle: early, dosage, combination, regular, whole course with intensification stage and continuative stage, adherence, directly observing therapy (DOT) v Antibiotics (bactericidal and bacteristatic) v The backbone o