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#155 #Cours #Facultaires #Médecine #Pneumologie #Tuberculose

Etape 1 : Contamination du sujet par transmission aérienne à partir d’une personne présentant une tuberculose bacillifère :

  • La contamination est due à l’inhalation d’« aérosols » de gouttelettes infectantes (contenant du BK) émises lors de la toux. Les gouttelettes, et donc quelques bacilles, atteignent les territoires alvéolaires (c’est le «foyer primaire»), entrainant la primo-infection tuberculeuse (PIT)
  • Le risque de contamination à l’origine d’une PIT est ainsi proportionnel à l’intensité de la toux, la contagiosité du cas (BAAR à l’examen direct, cavernes) et à la durée d’exposition

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Etape 2 : Le sujet développe une PIT le plus souvent asymptomatique responsable d’une infection tuberculeuse latente (ITL)

  • Au niveau du « foyer primaire » : les bacilles sont phagocytés par les macrophages alvéolaires, et se multiplient dans les macrophages
  • Les bacilles gagnent le ganglion hilaire satellite du foyer primaire
  • Dans les semaines suivant la PIT, une réponse immune à médiation cellulaire se développe au niveau du foyer primaire et des foyers secondaires.
    • Permettant le plus souvent de limiter la multiplication du BK
    • Responsable au niveau du foyer primaire et des foyers secondaires d’un afflux de cellules monocytaires d’allure épithélioïde avec au centre une nécrose dite « caséeuse », ces lésions sont appelées granulomes giganto-cellulaires avec nécrose caséeuse et contiennent quelques bacilles quiescents

  • L’ITL est par définition une PIT asymptomatique.

  • Parfois la PIT est « patente ».
    Elle s’accompagne d’une altération de l'état général (AEG), d’un érythème noueux, d’une kérato-conjonctivite phlycténulaire, d’adénopathies cervicales.
    La radiographie du thorax peut alors montrer des adénopathies médiastinales avec ou sans lésion parenchymateuse correspondant au foyer primaire (chancre d’inoculation)

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Etape 3 : développement de la TM

  • A n’importe quel moment, pendant l’ITL ou après l’ITL, la multiplication des bacilles quiescents peut survenir à le patient devient symptomatique
    10% des patients qui font une PIT développent une TM le plus souvent au cours des 2 premières années suivant la contamination

  • Le développement d’une TM est favorisé par :
    • l’immunodépression (infection VIH +++, tumeurs et hémopathies, traitements immunosuppresseursou anti-TNF)
    • les âges extrêmes
    • le diabète, l’insuffisance rénale, la malnutrition, l’alcoolisme/tabagisme
    • la précarité, la toxicomanie

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Tuberculose pulmonaire commune = la forme la plus « CLASSIQUE » de TM

Physiopathologie : lésions formées à partir de(s) foyer(s) secondaire(s) et/ou primaire(s) avec fonte du caséum et formation d’une caverne fistulisée dans l’arbre bronchique

  • Dissémination bronchogène au reste du poumon

Présentation clinique :

  • Pas de symptôme spécifique
  • Évolution sur plusieurs semaines à plusieurs mois, avec début insidieux
  • Signes généraux :
    • AEG : asthénie, anorexie, amaigrissement
    • Fébricule à prédominance nocturne
    • Sueurs nocturnes
  • Signes fonctionnels
    • Toux chronique ± expectorations
    • Hémoptysie : du simple crachat hémoptoïque à l’hémoptysie grave
    • Dyspnée, généralement tardive
  • Signes physiques :
    • Généralement absents
    • Possible syndrome pleural (en cas de pleurésie tuberculeuse associée)

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Les circonstances :

  • Toujours penser à la tuberculose devant :
    • Des signes cliniques évoluant depuis plusieurs semaines à plusieurs mois
    • Des infiltrats, nodules, et/ou cavernes au niveau des lobes supérieurs
    • Un contexte évocateur :
      • notion d’un contage
      • contexte socio-économique
      • immigration
      • vie en communauté
      • immunosuppression et infection VIH…

    • La tuberculose est la grande trompeuse : elle peut simuler de multiples pathologies pulmonaires
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Prélèvements

Les prélèvements respiratoires sont systématiques.
Toujours MULTIPLES et répétés.

  • Tuberculose pulmonaire
    • Si le patient crache :
      • Recherche de BAAR dans l’expectoration ; attention +++ : sur un ECBC "standard", on ne fait pas de recherche de BAAR !

    • Si le patient ne crache pas :
      • Tubage gastrique le matin à jeun avant tout lever
        • Durant la nuit, les sécrétions sont avalées, les BAAR résistent à l’acidité de l’estomac car ils sont acido-résistants
        • Le prélèvement doit donc être réalisé avant la vidange gastrique, le matin à jeun avant le lever
    • En cas d’échec (3 prélèvements négatifs à l'examen direct) ou en cas de suspicion de miliaire tuberculeuse :
      • Fibroscopie bronchique avec aspiration, dans un territoire atteint d’après l’imagerie.

  • Miliaire tuberculeuse :
    • Nécessité en plus des prélèvements respiratoires, d’hémocultures sur milieu spécifique des mycobactéries, d’ECBU adressé en mycobactériologie et éventuellement d’une myéloculture en cas de leuco-neutropénie.

  • Tuberculose extra-pulmonaire :
    • Ganglionnaire : ponction ou biopsie-exérèse d’une adénopathie accessible
    • Neuro-méningée : ponction lombaire
    • Génito-urinaire : prélèvements des urines 3 jours de suite

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Bactériologie

1 ère étape : examen direct

  • Recherche de BAAR par la coloration de Ziehl Nielsen (en quelques heures).
    • Cette recherche n’est positive que pour des concentrations bacillaires supérieures à 10^3 bacilles/ml.
      La négativité de l’examen direct n’élimine pas le diagnostic.

2 ème étape : culture sur milieux enrichis

  • Sur milieu solide (milieu de Löwenstein-Jensen, 3 à 4 semaines)
  • Sur milieu liquide 10 à 15 jours environ (mais doit être ensuite reconfirmé par un examen direct)
    • En parallèle des 2 étapes précédentes :
      • Tout examen direct ou culture positif doit être complété dans les 72h par la réalisation d’un test génotypique pour :
        • Confirmer qu’il s’agit d’une mycobactérie du complexe tuberculosis (pathogène certain)
        • Rechercher la présence d’une mutation sur les gènes qui codent pour la résistance aux antituberculeux

3ème étape : antibiogramme (obligatoire)

  • Consiste à mettre en culture les bacilles isolés, sur des milieux contenant différentes concentrations d’antibiotiques (méthode de référence)
  • Systématique
  • Si argument pour une résistance : souche transmise au Centre national de Référence des mycobactéries pour tester les antibiotiques de seconde ligne

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Isoniazide, abréviation INH

  • Effets secondaires :
    • Troubles digestifs (nausées)
    • Hépatite (de la simple élévation des transaminases à l’hépatite médicamenteuse sévère pouvant nécessiter l’arrêt du traitement)
      • Surveillance des transaminases
    • Polynévrites sensitivo-motrices en cas de carence en vitamine B6

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Rifampicine, abréviation RMP

  • Puissant inducteur enzymatique : attention aux interactions médicamenteuses, en particulier avec les anticoagulants oraux (surveillance INR), la pilule oestro-progestative (changer de mode de contraception), certains antirétroviraux (inhibiteurs de protéases), les corticoïdes, les digitaliques, …

  • Effets secondaires :
    • Réactions immuno-allergiques
    • Attention : coloration en orange des larmes, du sperme, des urines… (prévenir le patient : il ne s'agit pas d'un effet secondaire mais d'un phénomène normal)

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Pyrazinamide, abréviation PZA

  • Contre-indiqué en cas d’insuffisance hépatocellulaire et d’insuffisance rénale
  • Effets secondaires :
    • Cytolyse hépatique (plus tardif que l’INH, -> surveillance transaminases)
    • Hyperuricémie (généralement asymptomatique)

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Streptomycine et amikacine (aminosides)

  • Voie intraveineuse ou intramusculaire
  • La dose cumulée ne doit pas dépasser 120 g.
  • Plutôt utilisée en 2 ème intention
  • Toxicité rénale et auditive

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Principes :

  • Temps de doublement long (20H), -> prise unique quotidienne
  • Bacilles persistants dans les foyers tuberculeux -> traitement prolongé
  • Absorption RMP diminuée par repas -> à jeun (30 min -1h avant repas ou 2 h après)
  • Poly-antibiothérapie obligatoire :
    • Car risque d’émergence de mutants résistants en cas de « monothérapie »
    • Car nécessité d’assurer une action sur les 3 populations de BK
    • L’observance est capitale pour limiter le risque de rechute et le développement de souches résistantes.

  • Rôle fondamental des Centres de Lutte Anti-Tuberculeuse (CLAT) dans la prise en charge, en plus de l’enquête autour du cas index.

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Associations classiques

Schéma classique :

  • Quadrithérapie par INH+RMP+EMB+PZA pendant 2 mois n suivie par une bithérapie INH+RMP pendant 4 mois

Schéma alternatif (moins utilisé, mais qui peut être proposé en cas de contre-indication au PZA) :

  • Trithérapie par INH+RMP+ EMB pendant 3 mois n suivie d’une bithérapie par INH+RMP pendant 6 mois


Adapté aux résultats de l'antibiogramme dès réception (présence ou non de résistances avérées).



La durée de traitement recommandée, avec le schéma classique, est de 6 mois pour toutes les formes de tuberculose multi-sensible. Seule la tuberculose neuro-méningée doit être traitée de manière plus prolongée (9-12 mois).

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Examens ou actes à effectuer avant l'instauration d'un traitement antituberculeux.

  • Créatininémie, estimation du débit de filtration glomérulaire (DFG)
  • Uricémie
  • Transaminases
  • Hémogramme

  • Sérologie de dépistage VIH, à proposer systématiquement
  • Antigène HBs, Ac anti HBs et Ac anti HBc et anti VHC à proposer systématiquement

  • Examen ophtalmologique avec vision des couleurs et champ visuel : lors de la mise en route du traitement par EMB (mais peut être réalisé en différé car la mise en route du ttt est une urgence)

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Surveillance : efficacité, tolérance, observance

  • Clinique (J15, M1, M2, M4, M6, M9, M12), radiologique (M1, M2, M6, M12, M18 et 2 ans après la fin de traitement selon OMS) et bactériologique (J15, M1 (jusqu’à négativation), M2, M6)

  • Biologique : bilan hépatique hebdomadaire le premier mois, puis rythme de surveillance, dépendant du terrain
    • Sensibiliser les patients aux signes fonctionnels d’insuffisance hépatocellulaire
    • En cas de transaminases élevées mais < 3N :
      • Surveillance rapprochée jusqu’à normalisation
    • En cas de transaminases élevées entre 3 et 6N:
      • Arrêt du PZA et poursuite d’une trithérapie INH+RMP+EMB (3 mois la trithérapie + 6 mois de bithérapie)
    • En cas de transaminases élevées supérieures à 6N :
      • Arrêt INH et PZA, possible essai de réintroductio de l’INH à demi dose avec réalisation de dosages sériques après normalisation des paramètres biologiques
      • Si signe de gravité ou cytolyse majeure arrêt de tous les antituberculeux, déclaration pharmaco-vigilance, avis spécialisé pour ajout d’antituberculeux de 2ème ligne

  • Ophtalmologique: si traitement prolongé par EMB

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Isolement respiratoire pendant la période de contagiosité

  • Durée de l’isolement respiratoire :
    • Quand un patient est contagieux au moment du diagnostic d’une tuberculose, il est en général déjà contagieux depuis 3 mois et a donc potentiellement déjà contaminé son entourage proche
    • On considère en général qu’après 15 jours de traitement plein, on peut lever l’isolement respiratoire
    • La durée d'isolement respiratoire peut être prolongée, notamment en cas de tuberculose pulmonaire initialement très bacillifère, ou si présence d’enfants ou de personnes âgées au domicile

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Aucun de ces tests ne distingue ITL de TM.

  • Un examen clinique et une radiographie thoracique élimineront la TM.

  • Intradermoréaction à la tuberculine (IDR) encore appelée réaction cutanée tuberculinique (RCT)
    • Mise en évidence d’une réaction cutanée après injection locale d’antigènes mycobactériens, témoin de l’acquisition d’une immunité à médiation cellulaire
    • Non spécifique de M. tuberculosis, réaction également avec les antigènes de M. bovis (donc avec le BCG) et avec les antigènes de certaines mycobactéries atypiques
    • Peut être négative (= anergie tuberculinique) notamment en cas d’immunodépression
    • Modalités de réalisation :
      • Injection en intradermiqu de 0,1 ml de tuberculine (Tubertest ® )

    • Modalités de lecture :
      • 72 heures après
      • Mesure de l’induration autour du point de ponction
      • Ne pas prendre en compte les dimensions de la réaction érythémateuse

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Interprétation de l’IDR à la tuberculine:

  • En fonction des antécédents (tuberculose, PIT, immunodépression, pathologie grave évolutive…), et de son statut vaccinal (BCG et résultats d’anciennes IDR)
  • Interprétation difficile dans les 10 ans qui suivent la vaccination par le BCG

  • IDR négative = diamètre < 5 mm
  • IDR positive = diamètre ≥ 5 mm
  • Suspicion d’ITL
    • Lorsque le diamètre est supérieur à 10 mm en l’absence de vaccination antérieure par le BCG
    • Lorsque le diamètre de l’induration a augmenté de plus de 10 mm entre deux IDR à 3 mois d’intervalle (= virage tuberculinique)

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Les tests IGRA sont désormais pris en charge par l’Assurance Maladie pour :

  • Enfants migrants de moins de 15 ans provenant d’une zone de forte endémie tuberculeuse
  • Patients infectés par le VIH (dépistage systématique inclus dans le bilan initial d’un patient VIH)
  • Avant la mise en route d’un traitement par anti-TNF
  • Dans un contexte de prise en charge pluridisciplinaire, aide au diagnostic de tuberculose paucibacillaire en cas de diagnostic difficile chez l’enfant ou de tuberculose extra-pulmonaire.

La discussion clinico-biologique est indispensable chez les enfants de moins de 5 ans.

D’autres indications sont médicalement justifiées, mais ne sont pas prises en charge par l’Assurance Maladie :

  • Personnel professionnellement exposé:
    • à l’embauche
    • enquête autour d’un cas d’un adulte de plus de 15 ans (on peut donc utiliser soit un test IGRA soit l'IDR dans cette situation)
    • Le résultat des tests IGRA est disponible dans les jours qui suivent le prélèvement.
    • Le test peut être rendu indéterminé, positif ou négatif. En pratique, ces tests ne sont pas utilisés pour diagnostiquer une tuberculose active mais, tout comme l'IDR uniquement pour diagnostiquer une ITL

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Chimioprophylaxie secondaire (chez les patients les plus à risque de passer d’une ITL à une TM):

  • ITL chez les sujets de moins de 15 ans
  • ITL chez les sujets ≥15 ans
    • En cas de facteur de risque d’évolution rapide vers la TM.
      • Immunodépression

    • TL récente (< 2 ans), en pratique il s’agit des ITL dépistées lors de l’enquête autour d’un cas

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Modalités de la chimioprophylaxie :

  • INH en monothérapie pendant 6 mois (5 mg/kg/j)
  • INH 4 à 5 mg/kg/j + RMP 10 mg/kg/j pendant 3 à 4 mois
  • Mêmes précautions et surveillance que lors du traitement d’une TM
  • Ne pas oublier la déclaration obligatoire de toute ITL d’un enfant de moins de 15 ans

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Indications :

  • N’est plus obligatoire pour les enfants et les adolescents
  • Demeure obligatoire dans la loi malgré des recommandations contraires du Haut Comité de la Santé Publique pour les professionnels et étudiants des carrières sanitaires et sociales
  • Fortement recommandée pour enfants âgés de moins de 15 ans (dès 1 mois) qui présentent un facteur de risque lié à leur environnement ou leurs proches/ entourage :
    • Vivant en Guyane ou à Mayotte
    • En lien étroit avec une zone de forte endémie
      • Nés dans un pays de forte endémie
      • Ayant au moins un des parents originaires d’un de ces pays
      • Devant y séjourner de façon prolongée
    • Antécédents familiaux de tuberculose ou vivant dans des conditions sociales très défavorisées

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Contre-indications à la vaccination BCG :

  • Infection VIH : enfant infecté par le VIH ou né d’une mère infectée par le VIH
  • Déficits immunitaires congénitaux ou acquis
  • Traitements immunosuppresseurs
  • Dermatoses étendues évolutives

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Grossesse

  • INH : pas de tératogénicité pour INH, RMP et EMB
  • INH : supplémenter la mère en vitamine B6.
  • RMP : Risque d’hémorragie maternelle et néonatale précoce en cas de prescription au dernier trimestre, justifiant la prescription de vitamine K1.
  • PZA : pas de tératogénicité connue, mais toujours déconseillé en France en 2017, contrairement à la plupart des pays du monde.

Allaitement non conseillé.

En pratique :

  • Trithérapie INH+RMP+EMB en France

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VIH :

  • Risque de développer une tuberculose : multiplié par 7 chez le patient VIH+
  • La tuberculose classe le patient VIH en stade SIDA
  • Selon le nombre de lymphocytes CD4+ :
    • Plus de 350 CD4/mm 3 : symptômes classiques de tuberculose pulmonaire

    • < 200 CD4/mm 3 :
      • Haut risque de passage d’une ITL à une TM
      • Pas d’immunité cellulaire = pas de processus granulomateux
      • Souvent seule la fièvre est présente.
      • Y PENSER ++
      • Atteintes extra-respiratoires à rechercher systématiquement
      • Radiographie: peut être quasi normale

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Tuberculose MDR (multi drug resistant) :

  • Souche résistante à l’INH et à la RMP
  • Représente environ 2% des cas de tuberculoses en France (une centaine de cas par an)
  • Son traitement repose sur les associations d’antituberculeux de 2 ème ligne (fluoroquinolones, aminosides, etc…) et d’une prise en charge spécialisée

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La notification anonyme s'effectue auprès de l’ARS :

  • Sur formulaire type (cf annexe 1), anonyme
  • Puis l’information est relayée vers l’InVS (Santé Publique France), dans un but épidémiologique
  • Cas à déclarer
    • TM confirmée ou suspectée
      • Dans le but d’identifier les sujets contaminés
      • À partir du moment où un traitement a été débuté, même sans preuve bactériologique

    • ITL chez un enfant de moins de 15 ans
      • Dans le but d’identifier le sujet contaminant

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Les parents sont informés des éventuels signes de toxicité devant faire consulter en urgence : douleurs abdominales, vomissements, ictère. L'apparition de ces signes impose l'arrêt du trai- tement et la réalisation urgente d'un dosage de transaminases. L'ITL chez l'enfant < 15 ans est une maladie à déclaration obligatoire à l'ARS
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Tuberculose-maladie La fréquence du suivi clinique et radiologique doit être adaptée au tableau initial. Il peut être bimensuel initialement lorsque le risque de compression bronchique est important. Du fait de l'adjonction du pyrazinamide, la surveillance biologique des transaminases toutes les 2 semaines est impérative
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#155 #Cours #Facultaires #Médecine #Pédiatrie #Tuberculose
L'éviction de collectivité est obligatoire jusqu'à présentation d'un certificat médical de non- contagiosité.
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#IGRA #Tuberculose #U2D
The antigens, testing methods, and interpretation criteria differ among IGRA assays. Some NTM that infect humans (including M. marinum, M. szulgai, M. flavescens, and M. kansasii) contain gene sequences that encode for antigens used in IGRAs (early secreted antigenic target 6 [ESAT-6] or culture filtrate protein 10 [CFP-10]). Infection with these NTM has been shown to produce positive results in IGRAs using these antigens (as with the TST)
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most infections with environmental NTM, which can cause false-positive TSTs [6]. In addition, limited data suggest that IGRA results are not affected by intravesical BCG for bladder cancer [7]. <span>The antigens, testing methods, and interpretation criteria differ among IGRA assays. Some NTM that infect humans (including M. marinum, M. szulgai, M. flavescens, and M. kansasii) contain gene sequences that encode for antigens used in IGRAs (early secreted antigenic target 6 [ESAT-6] or culture filtrate protein 10 [CFP-10]). Infection with these NTM has been shown to produce positive results in IGRAs using these antigens (as with the TST) [8-10]. A large number of studies have evaluated IGRAs, and these have been summarized in systematic reviews and guidelines [2,4,11-22]. Assay antigens — A positive IGRA test may detect




#IGRA #Tuberculose #U2D
A newer assay, the QuantiFERON-TB Gold Plus (QFT-Plus), became available in the United States in July 2018 [23]. The QFT-Plus assay has two TB antigen tubes, unlike the older QFT-Gold assay (which has a single TB antigen tube). Both tubes contain peptide antigens ESAT-6 and CFP-10 (not TB7.7). The first tube contains peptides ESAT-6 and CFP-10 that are designed to elicit cellular responses from CD4+ T helper lymphocytes; the second tube contains ESAT-6 and CFP-10 and an additional set of "short" peptides, presumed derived from segments of ESAT-6 and CFP-10. These short peptides are targeted to induce cellular responses from CD8+ cytotoxic T lymphocytes. A positive result from either tube is interpreted as a positive test
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ive for M. tuberculosis infection if the interferon-gamma response to TB antigens is above the test cut-off (after subtracting the background interferon-gamma response in the negative control). <span>A newer assay, the QuantiFERON-TB Gold Plus (QFT-Plus), became available in the United States in July 2018 [23]. The QFT-Plus assay has two TB antigen tubes, unlike the older QFT-Gold assay (which has a single TB antigen tube). Both tubes contain peptide antigens ESAT-6 and CFP-10 (not TB7.7). The first tube contains peptides ESAT-6 and CFP-10 that are designed to elicit cellular responses from CD4+ T helper lymphocytes; the second tube contains ESAT-6 and CFP-10 and an additional set of "short" peptides, presumed derived from segments of ESAT-6 and CFP-10. These short peptides are targeted to induce cellular responses from CD8+ cytotoxic T lymphocytes. A positive result from either tube is interpreted as a positive test. ●The T-SPOT.TB is an enzyme-linked immunospot (ELISPOT) assay performed on separated and counted peripheral blood mononuclear cells (PBMCs), which include circulating monocytes and lym




#IGRA #Tuberculose #U2D
Since there is no way to establish TB infection with certainty in individuals who do not have TB disease, sensitivity for these tests has been defined by testing patients with culture-confirmed TB. The sensitivity for T-SPOT.TB appears to be higher than for QFT-GIT or TST (approximately 90, 80, and 80 percent, respectively) [13]. The higher sensitivity of T-SPOT.TB may be useful for evaluating individuals with immunosuppressive conditions. Specificity of the new QFT-Plus test, using short peptides, is not clear.
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s. Sensitivity and specificity — IGRAs have specificity >95 percent for diagnosis of TB infection, since they are not affected by BCG vaccination or most nontuberculous mycobacteria [12,13]. <span>Since there is no way to establish TB infection with certainty in individuals who do not have TB disease, sensitivity for these tests has been defined by testing patients with culture-confirmed TB. The sensitivity for T-SPOT.TB appears to be higher than for QFT-GIT or TST (approximately 90, 80, and 80 percent, respectively) [13]. The higher sensitivity of T-SPOT.TB may be useful for evaluating individuals with immunosuppressive conditions. Specificity of the new QFT-Plus test, using short peptides, is not clear. IGRA sensitivity is diminished by HIV infection [18]. Lower CD4 counts have been associated with higher rates of indeterminate IGRA results; this is especially the case with QFT-GIT [18




#IGRA #Tuberculose #U2D
IGRA sensitivity is diminished by HIV infection [18]. Lower CD4 counts have been associated with higher rates of indeterminate IGRA results; this is especially the case with QFT-GIT [18]. T-SPOT appears to be less affected by immunosuppression than QFT-GIT, likely because the procedure requires that an adequate number of peripheral blood mononuclear cells are placed in each test well (even if the overall peripheral blood lymphocyte count is low) and the test does not correct for absolute T lymphocyte number [18]
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) [13]. The higher sensitivity of T-SPOT.TB may be useful for evaluating individuals with immunosuppressive conditions. Specificity of the new QFT-Plus test, using short peptides, is not clear. <span>IGRA sensitivity is diminished by HIV infection [18]. Lower CD4 counts have been associated with higher rates of indeterminate IGRA results; this is especially the case with QFT-GIT [18]. T-SPOT appears to be less affected by immunosuppression than QFT-GIT, likely because the procedure requires that an adequate number of peripheral blood mononuclear cells are placed in each test well (even if the overall peripheral blood lymphocyte count is low) and the test does not correct for absolute T lymphocyte number [18]. It is uncertain whether the new QFT-Plus test is more sensitive than the QFT-GIT. For the diagnosis of active TB, IGRA sensitivity and specificity are poor, particularly in high TB inc




#IGRA #Tuberculose #U2D
Sensitivity is reduced because of the temporary anergy of the acute illness. Therefore, IGRAs should not be used for diagnosis of active TB
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ce settings [3,4]. Specificity is poor because these populations will have high prevalence of LTBI and the immune-based tests cannot distinguish between active disease and latent infection [4]. <span>Sensitivity is reduced because of the temporary anergy of the acute illness. Therefore, IGRAs should not be used for diagnosis of active TB. TST specificity may be reduced both by prior BCG vaccination and prior infection with nontuberculous mycobacteria, and depends on the cut-point for defining a positive test. The effect




#IGRA #Tuberculose #U2D
Negative IGRA — Among patients with a negative IGRA, LTBI is less likely than in those with a positive IGRA. However, false-negative results can occur because of immunosuppression (eg, HIV or active TB, anergy, treatment with biologic agents), faded immune memory, and technical-operational variability.
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reference range reported for that result and the clinical context in which the test was applied. Borderline or indeterminate results indicate uncertain likelihood of M. tuberculosis infection. <span>Negative IGRA — Among patients with a negative IGRA, LTBI is less likely than in those with a positive IGRA. However, false-negative results can occur because of immunosuppression (eg, HIV or active TB, anergy, treatment with biologic agents), faded immune memory, and technical-operational variability. Treatment for LTBI despite a negative IGRA may be considered on an individual basis. (See "Treatment of latent tuberculosis infection in HIV-uninfected nonpregnant adults" and "Treatmen




#IGRA #Tuberculose #U2D
Positive IGRA — Patients with a positive IGRA (in absence findings suggestive of active TB disease) should be considered for treatment of LTBI. The decision for treatment of LTBI is based on the likelihood of developing active TB if not treated balanced against the risk of adverse events if treated
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ividual basis. (See "Treatment of latent tuberculosis infection in HIV-uninfected nonpregnant adults" and "Treatment of latent tuberculosis infection in nonpregnant adults with HIV infection".) <span>Positive IGRA — Patients with a positive IGRA (in absence findings suggestive of active TB disease) should be considered for treatment of LTBI. The decision for treatment of LTBI is based on the likelihood of developing active TB if not treated balanced against the risk of adverse events if treated. (See "Treatment of latent tuberculosis infection in HIV-uninfected nonpregnant adults" and "Treatment of latent tuberculosis infection in nonpregnant adults with HIV infection" and "Tu




#IGRA #Tuberculose #U2D

● For the T-SPOT.TB assay:

Invalid – The result is reported as invalid when there is a detectable reaction in the negative control or an insufficient reaction in the positive control. An invalid result can indicate a problem with laboratory processing or a patient condition.

Borderline – Results where the higher of the spot counts is such that the (antigen plate minus Nil) spot count is five, six, or seven spots should be considered Borderline

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there is a strong response to the negative control (indicating a high level of spontaneous secretion of interferon-gamma in the absence of antigen), or a weak response to the positive control. <span>●For the T-SPOT.TB assay: •Invalid – The result is reported as invalid when there is a detectable reaction in the negative control or an insufficient reaction in the positive control. An invalid result can indicate a problem with laboratory processing or a patient condition. •Borderline – Results where the higher of the spot counts is such that the (antigen plate minus Nil) spot count is five, six, or seven spots should be considered Borderline. Repeat testing — Patients with uninterpretable IGRA results require repeat testing with IGRA (algorithm 1). If the patient has an illness associated with immune suppression, the T-SPOT




#IGRA #Tuberculose #U2D
Interpretation of serial IGRA tests is challenging due to unexpectedly high rates of conversions and reversions in low- and high-incidence settings [17,28-32]
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icity (depending on the BCG vaccination status) [27]. (See "Approach to diagnosis of latent tuberculosis infection (tuberculosis screening) in adults", section on 'Guidelines vary by country'.) <span>Interpretation of serial IGRA tests is challenging due to unexpectedly high rates of conversions and reversions in low- and high-incidence settings [17,28-32]. A number of studies have raised concerns regarding the optimal approach to interpretation of serial IGRA results, especially since most HCWs in the United States (and other low-inciden




#IGRA #Tuberculose #U2D
Use of simplistic definitions for conversions (ie, change from negative to positive result) may result in higher conversion rates than expected based on the known epidemiologic profile of a given population. IGRA reversions are more likely to occur among those with interferon-gamma values just above the diagnostic threshold and in those with a discordant profile (TST negative but IGRA positive) [2,14,17,28-31]
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IGRAs for serial testing is complicated by lack of data on optimal cutoffs and uncertainty regarding the optimal approach to interpretation of conversions and reversions [2,14,17,28-31,34,38]. <span>Use of simplistic definitions for conversions (ie, change from negative to positive result) may result in higher conversion rates than expected based on the known epidemiologic profile of a given population. IGRA reversions are more likely to occur among those with interferon-gamma values just above the diagnostic threshold and in those with a discordant profile (TST negative but IGRA positive) [2,14,17,28-31]. Therefore, for individuals with IGRA results that are close to threshold cutoff (eg, individuals with results of 0.35 to 1.0 international units/mL), repeat testing is suggested, altho




#IGRA #Tuberculose #U2D
Variability in response of a given individual observed on different samples collected on different days – Among 48 HCWs who underwent monthly testing with QuantiFERON-TB Gold for one year, conversions or reversions were observed in 52 percent of participants [47].
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[45]. ●Test reproducibility in different laboratories – Results have varied considerably when two samples taken from the same person on the same day are tested in different laboratories [46]. ●<span>Variability in response of a given individual observed on different samples collected on different days – Among 48 HCWs who underwent monthly testing with QuantiFERON-TB Gold for one year, conversions or reversions were observed in 52 percent of participants [47]. These issues with reproducibility have led to suggestions that a borderline range for IGRA interpretation be established for quantitative reporting of results, rather than reporting qua




#IGRA #Tuberculose #U2D
IGRAs may not be used for detection of latent tuberculosis in patients with leprosy, since the early secreted antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) antigens are cross reactive between Mycobacterium leprae and M. tuberculosis
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indeterminate results due to low mitogen response), and it is important to run both positive and negative controls with each assay. Areas for additional research have been identified [2,12,49]. <span>IGRAs may not be used for detection of latent tuberculosis in patients with leprosy, since the early secreted antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) antigens are cross reactive between Mycobacterium leprae and M. tuberculosis [50]. Uninterpretable results — Issues related to uninterpretable results are discussed above. (See 'Uninterpretable results' above.) Uninterpretable results may be due to immune suppre




#IGRA #Tuberculose #U2D
Window period — Data on time frame for IGRA conversion are limited; available evidence suggests that most IGRA conversions occur within four to seven weeks after TB exposure. However, in some cases, conversion may be delayed longer than three months; agreement between TST and IGRA show better concordance after this window period [53,54].
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clinician cannot rely on IGRA for clinical decision making, except to assume that the patient is probably anergic [52]. Other tests, risk factors, and clinical information must be used instead. <span>Window period — Data on time frame for IGRA conversion are limited; available evidence suggests that most IGRA conversions occur within four to seven weeks after TB exposure. However, in some cases, conversion may be delayed longer than three months; agreement between TST and IGRA show better concordance after this window period [53,54]. These are important considerations for using IGRA to screen contacts of a TB patient. If IGRAs are used in contact investigations, a single IGRA should be performed at the end of the wi




#IGRA #Tuberculose #U2D
Monitoring therapeutic response — IGRAs should not be used to monitor response to therapy, given potential problems with reproducibility, conversions, and reversions [55-57]. Although some data suggest that a large percentage of active TB patients become IGRA negative by the end of TB therapy, other studies do not support this; some data suggest that TB patients can remain IGRA positive even years after TB treatment
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reen contacts of a TB patient. If IGRAs are used in contact investigations, a single IGRA should be performed at the end of the window period (six- to eight-weeks after last known TB exposure). <span>Monitoring therapeutic response — IGRAs should not be used to monitor response to therapy, given potential problems with reproducibility, conversions, and reversions [55-57]. Although some data suggest that a large percentage of active TB patients become IGRA negative by the end of TB therapy, other studies do not support this; some data suggest that TB patients can remain IGRA positive even years after TB treatment. One study noted that changes in IGRA results were not associated with smear and culture conversion to negative results, reinforcing the lack of utility for active TB treatment monitori




#155 #Anatomopathologie #Cours #Facultaires #Médecine #Tuberculose

Définition d'inflammation granulomateuse

Il ne faut pas confondre un « granulome inflammatoire » et une « inflammation granulomateuse ».

  • Le « granulome inflammatoire » est un ensemble d'éléments cellulaires inflammatoires, associant des leucocytes et des macrophages, visible sur un prélèvement tissulaire, sans architecture particulière.

  • L'« inflammation granulomateuse » est une dénomination plus restrictive d'une lésion limitée, d'aspect nodulaire. Elle est majoritairement constituée de cellules mononucléées histiocytaires (macrophages, cellules épithélioïdes et/ou cellules géantes multinucléées) et de lymphocytes, avec participation de fibroblastes. Cette lésion correspond au granulome épithélioïde et gigantocellulaire. C'est la traduction morphologique visible d'une réaction immunitaire à médiation cellulaire de type Th1

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#155 #Anatomopathologie #Cours #Facultaires #Médecine #Tuberculose
Ces macrophages infectés sécrètent des médiateurs solubles permettant le recrutement d'autres populations cellulaires, telles que les neutrophiles, les cellules dendritiques (DC). Les DC sont des cellules présentatrices de l'antigène capables de migrer vers les organes lymphoïdes secondaires afin de recruter les lymphocytes T. De retour sur le site d'infection, les différent es populations cellulaires vont s'organiser afin de former un granulome nécessaire au confinement de l'infection
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#155 #Anatomopathologie #Cours #Facultaires #Médecine #Tuberculose

Les différentes étapes de cette réaction (fig. 20.1) :

  • La cellule présentatrice d'antigène sécrète de l'IL-12 induisant une différenciation de type Th1 au niveau des lymphocytes T, pour ensuite leur présenter l'antigène
  • Les lymphocytes Th1, en reconnaissant l'antigène, sécrètent de l'IL-2 et de l'interféron γ (IFN-γ)
  • L'IFN-γ active les macrophages provoquant une augmentation de leur bactéricidie et une sécrétion de TNF-α
  • Le TNF-α recrute de nombreux autres macrophages qui vont changer de morphologie (transformation en cellules épithélioïdes et formation de cellules géantes multinucléées) et former ainsi le granulome épithélioïde et gigantocellulaire

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#155 #Anatomopathologie #Cours #Facultaires #Médecine #Tuberculose

  • L'IFN-γ et le TNF-α sont les médiateurs essentiels de cette réaction immunitaire.

  • Toute réaction immunitaire Th1, quelle qu'en soit la cause, se traduira par la présence de granulomes épithélioïdes.

  • Ce mécanisme explique le principe des tests de type QuantiFERON ® pour le diagnostic de tuberculose, qui repose sur la mise en évidence d'une sécrétion d'IFN-γ par les lymphocytes du patient en présence d'antigènes spécifiques de M. tuberculosis, ainsi que le risque de développement d'une tuberculose maladie chez des patients avec infection latente traités par anti-TNF-α.

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#155 #Anatomopathologie #Cours #Facultaires #Médecine #Tuberculose
La pathogénicité des mycobactéries n'est pas liée à la sécrétion de toxines ou d'enzymes. Elle dépend de leur capacité à résister au pouvoir bactéricide des macrophages et donc de la rapidité de la mise en place d'une réponse immunitaire cellulaire T-dépendante.
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#155 #Anatomopathologie #Cours #Facultaires #Médecine #Tuberculose
Une bactérie Ziehl positive est un BAAR, et cette propriété est commune à toutes les mycobactéries
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#155 #Anatomopathologie #Cours #Facultaires #Médecine #Tuberculose
L'immunité à médiation cellulaire (type Th1) se développe en deux à trois semaines et induit la formation de granulomes épithélioïdes ± gigantocellulaires avec possibilité de nécrose caséeuse centrale au niveau du foyer pulmonaire primaire et du ganglion, permettant le plus souvent de limiter la multiplication du BK. Les éléments du « complexe primaire », foyer granulomateux pulmonaire initial associé à une adénopathie satellite de drainage, ne sont presque jamais biopsiés.
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#155 #Anatomopathologie #Cours #Facultaires #Médecine #Tuberculose
En cas de biopsie, il faut envoyer un fragment en anatomie pathologique pour recherche, sur les prélèvements fixés en formol et inclus en paraffine, de granulomes épithélioïdes et gigantocellulaires avec nécrose caséeuse centrale et coloration de Ziehl pour mise en évidence des bacilles. Cette coloration doit être faite dès lors que le diagnostic de tuberculose est suspecté (fig. 20.4), mais c'est une coloration peu performante et sa négativité n'élimine pas le diagnostic +++ (les bacilles sont très peu nombreux dans les lésions granulomateuses et dans la nécrose caséeuse)
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#155 #Anatomopathologie #Cours #Facultaires #Médecine #Tuberculose
N.B. : les ganglions doivent faire l'objet d'une biopsie-exérèse (risque de fistulisation après ponction). Les prélèvements tissulaires sont toujours à partager entre la bactériologie et l'anatomie pathologique
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Flashcard 4872279821580

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#DataScience
Question
The 3 Vs of Big Data.
Answer
Volume: Enormous amount of data generated from various sources.
Velocity: Large amount of data streaming in at great speeds, which requires quick data processing.
Variety: Different formats of data: Structured, Semi-structured, and Unstructured

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Flashcard 4872281656588

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#DataScience
Question
What is the sequential flow of Data Analytics?
Answer
Data acquisition, wrangling, exploration, modeling, and visualization

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Flashcard 4872283491596

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#DataScience
Question
Data Wrangling includes: (processes) ..
Answer
data cleansing, data manipulation, data aggregation, data split, and reshaping of data.

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Flashcard 4872285326604

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#DataScience #statistics
Question
Measurement of Central Tendency
Answer

Mean, Median, Mode.

Mean ~ average.
Mean is the point which indicates how centralized the data points are.
Suitable for symmetric distributions.

Median is the exact middle value.
Suitable for skewed distributions and for catching outliers in the dataset.

Mode is the most common value in the data (frequency).


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Flashcard 4872287161612

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#DataScience #statistics
Question
What is IQR.
Answer
Inter-quartile range is the distance between the 75th and 25th percentile. It’s essentially the middle 50% of the data.

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Flashcard 4872288996620

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#DataScience #statistics
Question
What is the Exploratory Data Analysis (EDA) technique?
Answer
Analysis of data using quantitative techniques
Analysis of data using graphical techniques
Suggests models that best fit the data

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Flashcard 4872290831628

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#DataScience #statistics
Question
three phases to hypothesis building
Answer

model building, model evaluation, and model deployment.

Phase 1: Model Building
• Identify best input variables
• Evaluate the model’s capacity to forecast with these variables


Phase 2: Model Evaluation
• Train and test the model for accuracy
• Optimize model accuracy, performance, and comparisons with other models


Phase 3: Model Deployment
• Use the model for prediction
• Use the model to compare actual outcome with expectations


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Flashcard 4872292666636

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#DataScience #statistics
Question
Null Hypothesis
Answer

There is no difference between the means of S1 and S2.

Opposite of the alternative hypothesis.


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Flashcard 4872294501644

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#DataScience #statistics
Question
Alternative Hypothesis?
Answer
Proposed model outcome is accurate and matches the data.
There is a difference between the means of S1 and S2.

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Flashcard 4872296336652

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#DataScience #statistics
Question
Forms of Data analysis presentation: (Communication)
Answer
• Visual graphs
• Plotting maps
• Reports
• Whitepaper reports
• PowerPoint presentations

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Flashcard 4872298171660

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#DataScience #statistics
Question
Benefits of data visualization:
Answer
• Simplifies quantitative information through visuals
• Shows the relationship between data points and variables
• Identifies patterns
• Establishes trends

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Flashcard 4872300006668

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#DataScience #statistics
Question
types of numerical data:
Answer
Discrete Data – Distinct or counted values
Example: Number of employees in a company or number of students in a class
Continuous Data – Values within a range that can be measured
Example: Height can be measured in feet or inches and weight can be measured in pounds or kilograms

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Flashcard 4872301841676

Tags
#DataScience #statistics
Question
two types of categorical data:
Answer
Cluster or group – Grouped values
Example: Students can be divided into different groups based on height – Tall, Medium, and Short
Ordinal data – Grouped values as per ranks
Example: A ranking system; a five-point scale with ranks like “Agree,” “Strongly agree,” and “Disagree”

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Flashcard 4872308657420

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#DataScience #statistics
Question
Which plotting technique is used for continuous data?
Answer
Line chart, Histogram

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Flashcard 4872311541004

Tags
#DataScience #python
Question
Which Python library is the main machine learning library?
Answer
Scikit-learn

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Flashcard 4872313376012

Tags
#DataScience #statistics
Question
Which measure of central tendency is used to catch outliers in the data?
Answer
Median

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Flashcard 4872315211020

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#DataScience
Question
In hypothesis testing, the proposed model is built on which dataset:
Answer
the training dataset.

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Flashcard 4872319667468

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#DataScience #python
Question
Beautiful soup library is used for _____.
Answer
web scraping

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Flashcard 4872323599628

Tags
#DataScience #statistics
Question
two major categories of statistics:
Answer
Descriptive analytics and inferential analytics

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Flashcard 4872325958924

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#DataScience #statistics
Question
Descriptive analysis ...
Answer

the main characteristics of the data.

eg. Max, min, mean, median, mode, iqr.


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Flashcard 4872330415372

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#DataScience #statistics
Question
Inferential analytics..
Answer

uses the probability theory to arrive at a conclusion.

Example:

Categorize height as “Tall,” “Medium,” and “Short”
Take a sample to study from the population.

z-test or t test?


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Flashcard 4872332250380

Tags
#DataScience #statistics
Question
Population and Sample
Answer
A sample is:
• The part/piece drawn from the population
• The subset of the population
• A random selection to represent the characteristics of the population
Representative analysis of the entire population (normal distribution, of a certain size, eg 30)

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Flashcard 4872335396108

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#DataScience #statistics
Question
Range of the data refers to
Answer
minimum and maximum values.

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Flashcard 4872338017548

Tags
#DataScience #statistics
Question
Frequency indicates
Answer
the number of occurrences of a data value.

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Flashcard 4872341687564

Tags
#DataScience #statistics
Question
Central tendency indicates data accumulation .. eg.
Answer
toward the middle of the distribution (normal) or toward the end (left or right skewed)

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Flashcard 4872345881868

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#DataScience #statistics
Question
A percentile (or a centile) indicates the value
Answer

below which a given percentage of observations fall.

Eg 25th percentile, is 25% and below.


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Flashcard 4872349027596

Tags
#DataScience #statistics
Question
Histogram characteristics
Answer
“bin” the range of values.
Bins are consecutive, non-overlapping intervals of a variable.
Bins are of equal size.
The bars represent the bins.
The height of the bar represents the frequency of the values in the bin.
It helps assess the probability distribution of a variable.

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Flashcard 4872351911180

Tags
#DataScience #statistics
Question
Bell Curve – Normal Distribution
Answer
Symmetric around the mean,
Symmetric on both sides of the center,
Having equal mean, median, and mode values,
Denser in the center and less dense in the tails or sides,
Defined by mean and standard deviation.
Known as the “Gaussian” curve.

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Flashcard 4872354794764

Tags
#DataScience #statistics
Question
Bell curve is divided into three parts
Answer
Peak = Within one standard deviation from the mean. (Top, highest point)
Flanks = Between one and two standard deviations from the mean.
Tail = Beyond two standard deviations from the mean.

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Flashcard 4872357678348

Tags
#DataScience #statistics
Question
Bell Curve – Left Skewed
Answer
The data is left skewed. (ascends gradually)
Mean < Median < Mode
The distribution is negatively skewed.
Left tail contains large distributions. (most of the values on the right)

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Flashcard 4872361086220

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#DataScience #statistics
Question
Bell Curve – Right Skewed
Answer

The data is right skewed. (descends gradually)
The distribution is positively skewed.
Mean > Median > Mode
Right tail contains large distributions.

(most of the data on the left)


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Flashcard 4872362659084

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#DataScience #statistics
Question
Kurtosis describes..
Answer

the shape of a probability distribution.

Platykurtic is negative kurtosis. (flatter curve). (worst kind)
Mesokurtic represents a normal distribution curve.
Leptokurtic is positive kurtosis. (Very narrow sharp curve)


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Flashcard 4872364494092

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#DataScience
Question
Hypothesis Testing – Error Types
Answer

The null hypothesis corresponds to the position of the defendant: just as he is presumed to be innocent until proven guilty, so is the null hypothesis presumed to be true until the data provide convincing evidence against it.

Type I Error (α)
• Rejects the null hypothesis when it is true
• The probability of making Type I error is represented by α

(also known as a "false positive")

In terms of the courtroom example, a type I error corresponds to convicting an innocent defendant.

Type II Error (β)
• Fails to Reject the null hypothesis when it false
• The probability of making Type II error is represented by β

(also known as a "false negative" )

The alternative hypothesis corresponds to the position against the defendant.
In terms of the courtroom example, a type II error corresponds to acquitting a criminal.


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Flashcard 4872366853388

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#DataScience
Question
Reject the null hypothesis if p-value ? α
Answer
Reject the null hypothesis if p-value < α

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Flashcard 4872386252044

Tags
#DataScience #statistics
Question
Chi-Square Test
Answer

Test of Association:
To determine whether one variable is associated with a different variable.

Test of Independence:
To determine whether the observed value of one variable depends on the observed value of a different variable.

Test is usually applied when there are two categorical variables from a single population.


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Flashcard 4872390446348

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#DataScience #statistics
Question
In Chi-Square test, there is no association of variables if:
Answer
Observed Frequency = Expected Frequency

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Flashcard 4872393067788

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#DataScience #statistics
Question
A Correlation matrix is
Answer

a square matrix that compares a large number of variables.

Correlation coefficient measures the extent to which two variables tend to change together.
The coefficient describes both the strength and direction of the relationship.


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Flashcard 4872398048524

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#DataScience #statistics
Question
Pearson product moment correlation. It evaluates the ___ relationship between two __ variables.
Answer
linear relationship between two continuous variables.

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Flashcard 4872401194252

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#DataScience #statistics
Question
Spearman rank order correlation. It evaluates the __ relationship between two __ or __ variables.
Answer
It evaluates the monotonic relationship between two continuous or ordinal
variables.

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Flashcard 4872407223564

Tags
#DataScience #statistics
Question
Identify the parameters that characterize a bell curve.
Answer
Bell Curve is completely characterized by mean and standard deviation.

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Flashcard 4872409582860

Tags
#DataScience #statistics
Question
Standard deviation is the _____of variance.
Answer
square root of variance.

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Flashcard 4872412990732

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#DataScience #python
Question
Python - set variable to boolean or null
Answer

x = None

x = True

x = False


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Flashcard 4872416136460

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#python
Question

A tuple is:

  1. ? dimensional
  2. mutable/immutable
  3. ordered/unordered sequence of items
  4. single/mixed data types
Answer

A tuple is:

  1. 1 dimensional
  2. immutable
  3. ordered
  4. mixed data types

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Flashcard 4872419544332

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#python
Question

A List is a :

  1. ? dimensional
  2. mutable/immutable
  3. ordered/unordered sequence of items
  4. single/mixed data types
Answer

A List is a :

  1. 1 dimensional
  2. mutable
  3. ordered
  4. mixed data types

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Flashcard 4872424262924

Tags
#python
Question

Modifying a list.

  1. Modify a list: Add new items
  2. Modify a list: Remove items
  3. Access and remove list data using
  4. Modify a list: Insert a new item at a certain index
Answer
  1. Modify a list: Add new items
    someList.append('Add')
  2. Modify a list: Remove items
    someList.remove('remove')
  3. Access and remove list data using
    someList.pop(2)
    #shows the thing that was removed
  4. Modify a list: Insert a new item at a certain index
    someList.insert(index,value)

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Flashcard 4872429767948

Tags
#python
Question

Accessing Tuples/Lists

  1. Access with positive index
  2. Access with negative index
  3. Count starts with the first index , but stops before the second index.
  4. Even for negative indices, the count stops before the second index
Answer

Accessing Tuples/Lists

  1. Access with positive index: someList[1]
  2. Access with negative index: someList[-1] from the end
  3. Count starts with the first index , but stops before the second index. : someList[1]:4 for items 1 to 3
  4. Even for negative indices, the count stops before the second index: someList[1:-1] for items 1 to before the last?

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Flashcard 4872434748684

Tags
#python
Question
Dictionaries store a mapping between a
Answer
Dictionaries store a mapping between a set of keys and a set of values.

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Flashcard 4872436845836

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#python
Question
Python Dictionary synyax
Create a dictionary:
View entire dictionary:
View only keys:
View only values:
Answer
Python Dictionary synyax
Create a dictionary: someDic = {'someKey1':1 , 'someKey2':[1:5], 'someKey3':'some value 3'}
View entire dictionary:someDic
View only keys:someDic.keys()
View only values: someDic.values()

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Flashcard 4872438680844

Tags
#python
Question
Python Dictionary - Access and Modify dict Elements
Access with key:
Modify dictionary, update:
Modify dictionary, delete:
Answer
Python Dictionary - Access and Modify dict Elements
Access with key: someDic['someKey1']
Modify dictionary, update: someDic({'someKey':'some updated value'})
Modify dictionary, delete: del someDic['someKey']

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Flashcard 4872440515852

Tags
#python
Question
#python. A set is an ordered/unordered collection of __ elements.
Answer
A set is an unordered collection of unique elements.

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Flashcard 4872442350860

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#python
Question
#python. Set syntax
Create sets:
OR – Union set operation:
AND – Intersection set operation:
View the output of the NOT operation:
Answer
#python. Set syntax
Create sets: set1 = set(['value1','value2','value3'])
OR – Union set operation: set 1| set2
AND – Intersection set operation: set1 & set2
View the output of the NOT operation: ?

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Flashcard 4872444972300

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#python
Question
#python. Basic Operator: “in” Uses?
Answer
#python. Basic Operator: “in”
value in list/tuple/set? : 'Nick' in studentList
character in string: 'n' in someString

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Flashcard 4872725204236

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#python
Question
#python. Basic Operator: “+”
Answer
#python. Basic Operator: “+”
The “plus” operator produces a new tuple, list, or string whose value is the concatenation of its arguments.

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Flashcard 4872727825676

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#python
Question
#python. Basic Operator: “*”
Answer
#python. Basic Operator: “*”
The “multiplication” operator produces a new tuple, list, or string that “repeats” the original content.

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Flashcard 4872729660684

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#python
Question
#python. Use __ to create a function and assign it a name.
Answer

#python. Use def to create a function and assign it a name.

def functionName(args):
xxx

note: indentation is important.


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Electric circuit theory and electromagnetic theory are the two funda- mental theories upon which all branches of electrical engineering are built
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Flashcard 4881206086924

Question
Electric circuit theory and [...] are the two funda- mental theories upon which all branches of electrical engineering are built
Answer
electromagnetic theory

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Electric circuit theory and electromagnetic theory are the two funda- mental theories upon which all branches of electrical engineering are built

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Flashcard 4881207659788

Question
Electric [...] and electromagnetic theory are the two funda- mental theories upon which all branches of electrical engineering are built
Answer
circuit theory

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Electric circuit theory and electromagnetic theory are the two funda- mental theories upon which all branches of electrical engineering are built

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