1、 Tuberculosis in childrenYinghu Chenchildrens hospitalEmail:PediatricsEtiology:Tubercle bacillus Oder Actinomycetales Family mycobacteriaceae Genus Mycobacterium(M.)Species M.tuberculosis M.bovis Non-TB M.CharacteristicsvAcid-fastnessvSlow-growingvUnusual resistancevMulti-Drug Resistance strain(MDR)
2、Etiologyv Tubercle bacilli Mycobacterium tuberculosis,Mycobacterium bovis,v Non-spore forming,nonmotile,pleomorphic,obligate aerobes,weakly G+curved rods,2-4m longv Lipid-rich cell wallv Acid fast bacilliv Grow slowlyAcid fast stainGrow slowlyvThe generation time:12-24hrsvOn solid culture media:3-6w
3、,and susceptibility:another 4wvOn selective liquid media with radio labeled nutrients:1-3w,susceptibility:3-5dvNucleic acid amplification(NAA):several hoursSelective resistant109 drug-susceptible tubercle bacilliXXXXXXXXXXXXXXXNatural resistantXXXXXXXXXXXXXXXIsoniazidXXXXXXXXXXXXXXXXMultiplyNatural
4、resistantXXXXXXXXXXXXXXXXXXXXXXXXXXRifampinXMultiplyIsoniazid resistIsoniazid and Rifampin resist108EpidemiologyvSource of infectionvRoute of transmissionvHigh-risk populationSource of infection Open Pulmonary Tuberculosis withv acid-fast smear of sputum(+)v copious production of thin sputumv severe
5、 and forceful coughv extensive upper lobe infiltrate or cavity Young children with TB rarely infect others High-risk populationvEnvironmental factors:socioeconomic status overcrowding poor nutrition inadequate health carevGenetic background:twin racial difference HLA BW35Route of transmissionvBy res
6、piratory tract:airbone mucus droplet nuclei(10 m).contaminated dustvBy alimentary tract raw milk contaminated foodvBy others:(Placenta,skin)Transmission rarely occurs by direct contact with an infected discharge or contaminated fomite!TB-specific cellular immunitybut incomplete resistance Acquired i
7、mmunityInfection or not:Determining factors vVirulence of the TB strainvInoculationvThe hypersensitivity of the individual tissuesvNutritional or social statusvImmunologic statusvGenetic backgroundAcquired specific immunityImmunity:a double-edge swordTuberculin test：principle&method vBased on delaye
8、d type hypersensitivity(type IV)vTwo antigen preparations:Old tuberculin,OT Protein purified derivative,PPDvIntradermal injection of 0.1ml containing 5 tuberculin units of PPD(Mantoux test)Tuberculin skin test:result evaluationvThe amount of induration should be measured by a trained person 4872hour
9、s after administrationvIntensity:or:=20mm strong-positive +:blister,ulcer,lymphangitis,double rings What does it mean:Positive resultvPrevious infection with TBvPrevious vaccination with BCGvActive tuberculosis =15mm conversion occurring within 2 yearsWhat does it mean:Negative result vNot infected
10、with TBvFalse-negative:incubation period immunosuppression or immunodeficiency technical error or improper reagents Prevention of TBvAvoiding contact with those with open pulmonary tuberculosisvBCG(Bacillus Calmette-Guerin)vaccinationvChemoprophylaxisSpreading of M.tuberculosis Initial focus (local
11、infection at the portal of entry)Draining lymphatic vessles Regional lymph nodes Blood Other tissues of the body Primary Pulmonary TuberculosisPediatricsPrimary pulmonary tuberculosis:Clinical types Initial focusvPrimary complex lymphangitis Lymphadenitisv Bronchial lymph node tuberculosisPrimary pu
12、lmonary tuberculosis:Clinical manifestationvSurprisingly thin(subclinical)vInfants more likely to develop signs and symptomsvNonproductive cough and mild dyspnea as the most common symptomsPrimary pulmonary tuberculosis:Less common symptomsvSystemic complaints fever,night sweats,failure-to-thrive,an
13、orexia,etc.vBronchial irritation or obstruction localized wheezing DiagnosisvHistory vClinical manifestationvTuberculin testvX-RayvIsolation of M.tuberculosis vFiberoptic bronchoscopyPrognosisvImprove or dissolvev Completely resolutionv Indurationv Calcification v Local progress v Exacerbation absor
14、ption fibrosis calcificationImproveProgress expansion,PE EBTB +emphysema+atelectasisDeterioratebronchial primary caseous miliary metastasis cavity Pneumonia pneumoniaPrimary complexTB of Bronchial lymph nodeThe development of primary complexTuberculous meningitisPediatricsTuberculous meningitis:intr
15、oductionvMost common in children of 6mo4yrvUsually develops during the lymphohematogenous dissemination of the primary infectionvHigh mortality and high morbidityClinical manifestationvStage 1:Prodromal stagevStage 2:Transitional stage vStage 3:Terminal stage Stage 1:Prodromal stagevLasts 12wkvNonsp
16、ecific symptoms:character alteration,fever,headache,malaise,irritability,sleepyvFocal neurologic signs absent Stage 2:Transitional stagevIncreased intracranial pressure:headache,projectile vomiting,papilledemavMeningeal irritation:nuchal rigidity,Kernigs sign,Brudzinskis signvToxic appearance:fever,
17、anorexia,nauseavOthers:cranial nerve palsies,convulsionStage 3:Terminal stagev13wkvExacerbation of neurologic symptomsvVery thin with scaphoid abdomenvElectrolyte imbalance SIADH（syndrome of inappropriate antidiuretic hormone secretion）Cerebral salt losing syndromeDiagnosisvThe earlier,the better.vC
18、autiousnessvLumber tap and CSF examinationTypical CSF picturevPressurevAppearance ground-glassvCell counts 50500106/L,L.predominatesvProteinvGlucose 40mg/dl，or CSF/blood 1000 0200 v predominate L PMN LvProtein or-vGlucose -vChloride -vPathogensTreatmentvAntituberculosis therapy:vCorticosteroidsvSymp
19、tomatic managementvSupportive careCombination chemotherapy intensive treatment consolidation treatmentDirectly Observed Therapy Shortcouse(DOTS)Treatmentv Principle:early,dosage,combination,regular,whole course with intensification stage and continuative stage,adherence,directly observing therapy(DO
20、T)v Antibiotics(bactericidal and bacteristatic)v The backbone of antimicrobial:isoniazid,rifampin,pyrazinamidev Other drugs in special circumstances to prevent emergence of reisistance:ethambutol,ethionamide,streptomycin,and cycloserine v Drug resistanthttp:/whqlibdoc.who.int/publications/2010/97892
21、41547833_eng.pdfhttp:/whqlibdoc.who.int/publications/2010/9789241547833_eng.pdfHeal or not:determining factorsvPromptness and adequacy of therapyvAge and immunologic status vExistence of drug resistancePrognosisKeypoints(1)vPPD test:method&significancevPrimary complex:definition&outcomevSymptoms of tuberculous meningitis:prodromal&transitional stagevTypical CSF picture of tuberculous meningitis
