TUBERCULOSIS

TUBERCULOSISTUBERCULOSIS

(An ancient persistent (An ancient persistent continuing human continuing human

companion)companion)

Dr. Awadh Al-AnaziDr. Awadh Al-Anazi

WHAT IS IT?WHAT IS IT?

Bacterial infectionBacterial infection

Caused by Caused by Mycobacterium Mycobacterium tuberculosis tuberculosis (also called (also called tubercle bacillustubercle bacillus)) Damages a person’s lungs or Damages a person’s lungs or

other parts of the body other parts of the body

Fatal if not treated properlyFatal if not treated properly

SYMPTOMSSYMPTOMS

Perpetual CoughPerpetual Cough FeverFever Weight lossWeight loss Night sweatsNight sweats Loss of appetiteLoss of appetite FatigueFatigue Swollen glands (lymph nodes)Swollen glands (lymph nodes) ChillsChills Pain while breathingPain while breathing

MICROBIOLOGYMICROBIOLOGY

Organism: Organism: – Mycobacterium tuberculosisMycobacterium tuberculosis– AerobicAerobic– Non-spore forming ,non-motileNon-spore forming ,non-motile– Rod..: 2—5 mm longRod..: 2—5 mm long– Resistant to disinfectantResistant to disinfectant– Once stained it resists decolorization with Once stained it resists decolorization with

acid and alcohol facultative intracellular acid and alcohol facultative intracellular organismorganism

Human is the main reservoir of M TBHuman is the main reservoir of M TB

EPIDEMIOLOGYEPIDEMIOLOGY

It is a world wide diseaseIt is a world wide disease Tb infects 1.7 billion with 3 million Tb infects 1.7 billion with 3 million

deaths/yrdeaths/yr UK: 1st half of 20UK: 1st half of 20thth century: a lot of century: a lot of

death secondary to TB epidemicdeath secondary to TB epidemic 90% of cases and 95% of death 90% of cases and 95% of death

occurred in developing countries.occurred in developing countries. No of cases in developed countries No of cases in developed countries

has declined because of: has declined because of:


Case finding and chemotherapyCase finding and chemotherapy Tuberculous infection: a state in Tuberculous infection: a state in

which the tubercle bacillus is which the tubercle bacillus is established in the body without established in the body without symptoms.symptoms.

Tuberculous disease: a state in Tuberculous disease: a state in which one or more organs of the which one or more organs of the body becomes diseased by the body becomes diseased by the disease.disease.

Improved nutritionImproved nutrition


What increases the spread of the What increases the spread of the disease: disease:

1) crowding living 1) crowding living

2) migration of people from 2) migration of people from endemic endemic area.area.

10% of infected people ---- active 10% of infected people ---- active diseasedisease

50%of active disease --- 50%of active disease --- contagiouscontagious


What increases the risk of What increases the risk of developing disease after TB developing disease after TB infection ?infection ?– Infecting doseInfecting dose– Host factorsHost factors

age: under 5 yrs age: under 5 yrs debilitating illness and poor nutritiondebilitating illness and poor nutrition alcoholismalcoholism gastrectomygastrectomy diabetes mellitusdiabetes mellitus

MODE OF SPREAD & MODE OF SPREAD & TRANSMISSIONTRANSMISSION

Inhalation of droplet nucleiInhalation of droplet nuclei Spreads through the air when Spreads through the air when

a person with active TB: a person with active TB: Coughs/ Speaks/ Laughs/ Sneezes/ Coughs/ Speaks/ Laughs/ Sneezes/

SingsSings Another person breathes in the Another person breathes in the

bacteria and becomes infectedbacteria and becomes infected

INSIDE THE BODYINSIDE THE BODY

Breathe in infected air and bacilli go to lungs Breathe in infected air and bacilli go to lungs through bronchiolesthrough bronchioles

Bacilli infect alveoliBacilli infect alveoli

Macrophages attack bacteria, but some Macrophages attack bacteria, but some survivesurvive

Infected macrophages separate and form Infected macrophages separate and form tuberclestubercles

Dead cells form granulomasDead cells form granulomas

INSIDE THE BODY (cont.)INSIDE THE BODY (cont.)

As a person breathes in infected air, the bacilli go the lungs As a person breathes in infected air, the bacilli go the lungs through the bronchioles. At the end of the bronchioles are alveoli, through the bronchioles. At the end of the bronchioles are alveoli, which are balloon-like sacs where blood takes oxygen from inhaled which are balloon-like sacs where blood takes oxygen from inhaled air and releases carbon dioxide into the air exhaled. air and releases carbon dioxide into the air exhaled.

TB bacilli infect the alveoli and the bodyπs immune system begins TB bacilli infect the alveoli and the bodyπs immune system begins to fight them. Macrophages — specialized white blood cells that to fight them. Macrophages — specialized white blood cells that ingest harmful organisms — begin to surround and "wall off" the ingest harmful organisms — begin to surround and "wall off" the tuberculosis bacteria in the lungs, much like a scab forming over a tuberculosis bacteria in the lungs, much like a scab forming over a wound. wound.

Then, special immune system cells surround and separate the Then, special immune system cells surround and separate the infected macrophages. The mass resulting from the separated infected macrophages. The mass resulting from the separated infected macrophages are hard, grayish nodules called tubercles.infected macrophages are hard, grayish nodules called tubercles.

INSIDE THE BODY (cont.)INSIDE THE BODY (cont.)

Active TB spreads through the lymphatic system to Active TB spreads through the lymphatic system to other parts of the body. In these other parts, the other parts of the body. In these other parts, the immune system kills bacilli, but immune cells and local immune system kills bacilli, but immune cells and local tissue die as well. The dead cells form masses called tissue die as well. The dead cells form masses called granulomas, where bacilli survive but don’t grow. granulomas, where bacilli survive but don’t grow.

As more lung tissue is destroyed and granulomas As more lung tissue is destroyed and granulomas expand, cavities develop in the lungs, which causes expand, cavities develop in the lungs, which causes more coughing and shortness of breathe. Granulomas more coughing and shortness of breathe. Granulomas can also eat away at blood vessels which causes can also eat away at blood vessels which causes bleeding in the lungs, and bloody sputum.bleeding in the lungs, and bloody sputum.

PATHOGENESISPATHOGENESIS

Droplet nuclie ---terminal air Droplet nuclie ---terminal air space ---space ---

Multiplication … initial focusMultiplication … initial focus– SubpleuralSubpleural– 75%single75%single

Migration through blood and Migration through blood and lymph node --- another focuslymph node --- another focus

Ingestion of the bacteria by the Ingestion of the bacteria by the macrophage --- slow multiplicationmacrophage --- slow multiplication

IMMUNOLOGICAL FEATUREIMMUNOLOGICAL FEATURE

TB require CMI for its controlTB require CMI for its control Ab response is rich but has no role Ab response is rich but has no role Multiplication proceeds for weeks Multiplication proceeds for weeks

both in:both in:– initial focusinitial focus– lymphohaematogenous metastatic focilymphohaematogenous metastatic foci

Until development of ... cell Until development of ... cell mediated immunitymediated immunity

CLINICAL FEATURESCLINICAL FEATURESACTIVE vs. LATENT INFECTIONACTIVE vs. LATENT INFECTION

Unhealthy personUnhealthy person

Bacilli overwhelm immune systemBacilli overwhelm immune system

Bacilli break out of tubercles in alveoli and Bacilli break out of tubercles in alveoli and spread through bloodstream spread through bloodstream

This is (active) TBThis is (active) TB

Healthy personHealthy person

Initial infection controlled by immune systemInitial infection controlled by immune system

Bacilli remain confined in tubercles for yearsBacilli remain confined in tubercles for years

This is(latent) TBThis is(latent) TB

MOST SUSCEPTIBLEMOST SUSCEPTIBLE

People at higher risk of TB infection People at higher risk of TB infection

Close contacts with people with infectious TBClose contacts with people with infectious TB

People born in areas where TB is commonPeople born in areas where TB is common

People with poor access to health carePeople with poor access to health care

People who inject illicit drugsPeople who inject illicit drugs

People who live or work in residential facilitiesPeople who live or work in residential facilities

Health care professionalsHealth care professionals

The elderlyThe elderly

MOST SUSCEPTIBLE (CONT.)MOST SUSCEPTIBLE (CONT.)

People at higher risk of active TB diseasePeople at higher risk of active TB disease

People with weak immune systems People with weak immune systems (especially those with HIV or AIDS) (especially those with HIV or AIDS)

People with diabetes or silicosisPeople with diabetes or silicosis

People infected within the last 2 yearsPeople infected within the last 2 years

People with chest x-rays that show previous TB People with chest x-rays that show previous TB diseasedisease

Illicit drug and alcohol abusersIllicit drug and alcohol abusers

CLINICAL FEATURESCLINICAL FEATURES

Pulmonary 80%Pulmonary 80% Extra pulmonary 20%Extra pulmonary 20% Pulmonary tuberculosisPulmonary tuberculosis Primary: the lung is the 1Primary: the lung is the 1stst organ organ

involved ... middle and lower lobe.involved ... middle and lower lobe. Health: asymptomatic Health: asymptomatic Heals spontaneouslyHeals spontaneously CXR normal.CXR normal.


MalnutritionMalnutrition HIVHIV Severe casesSevere cases

– primary lesion progress to clinical primary lesion progress to clinical illnessillness

– cavitating pneumoniacavitating pneumonia– lymphatic spread and lobar collapse lymphatic spread and lobar collapse

due to LNdue to LN 40% haematogenous 40% haematogenous

dissemination dissemination


In children In children Asymptomatic state may cause Asymptomatic state may cause

miliary tuberculosis and TB miliary tuberculosis and TB meningitis meningitis

Clinical featuresClinical features

Post primary (reactivation)Post primary (reactivation) Result from endogenous Result from endogenous

reactivation of latent infection reactivation of latent infection and manifest clinically : and manifest clinically : – fever and night sweatfever and night sweat– weight lossweight loss– cough… non-productive then cough… non-productive then

productiveproductive And may have haemoptysisAnd may have haemoptysis Signs: rales in chest examSigns: rales in chest exam

C .F cont.C .F cont.

Extra pulmonary Extra pulmonary – lymph node lymph node – pleural pleural – bone and jointbone and joint– meningesmeninges– peritoniumperitonium

C F.CONTC F.CONT

Tuberculous lymphadenitis … 25 Tuberculous lymphadenitis … 25 %%

The commonestThe commonest Localized painless swellingLocalized painless swelling Common sites: cervical & Common sites: cervical &

supraclavicularsupraclavicular Early: glands are discreteEarly: glands are discrete Late: glands are matted -/+ sinusLate: glands are matted -/+ sinus Dx: FNA 30% in biopsy for histo Dx: FNA 30% in biopsy for histo

and cultureand culture

C.F contC.F cont

Pleural TbPleural Tb Result form penetration by few Result form penetration by few

bacilli into the pleural space bacilli into the pleural space resulting into :resulting into :– pleural effusion and fever pleural effusion and fever – DX; aspirate --- exudate DX; aspirate --- exudate – AFB rarely seen AFB rarely seen – culture 30% positiveculture 30% positive– BX 80% granulomaBX 80% granuloma

C.F. contC.F. cont

Skeletal Tb Skeletal Tb Source: Source:

– reactivation of haematogenous focusreactivation of haematogenous focus– spread from an adjacent LN spread from an adjacent LN

Common sites: spine --- hips --- Common sites: spine --- hips --- kneesknees

Spinal Tb:Spinal Tb: Dorsal site is the commonest site Dorsal site is the commonest site

C.F.contC.F.cont

Involve two vertebral bodies and Involve two vertebral bodies and destroy the disc in between.destroy the disc in between.

Advance disease Advance disease Collapse fracture of the bodies ------Collapse fracture of the bodies ------ Kyphosis and gibbus deformityKyphosis and gibbus deformity Paravertebral abscess(cold abcess)Paravertebral abscess(cold abcess) Dx: ct scan and MRIDx: ct scan and MRI Biopsy: histopathBiopsy: histopath

C.F.contC.F.cont

Tuberculous meningitis Tuberculous meningitis Most often: children and may affect Most often: children and may affect

adultadult

Source: Source: – blood spread blood spread – rupture of a sub-ependymal tuberclerupture of a sub-ependymal tubercle

C.F.contC.F.cont

Symptoms: Symptoms: – fever fever – headache headache – neck rigidity neck rigidity

Disease typically evolve in 2 wks. Disease typically evolve in 2 wks. Dx; csf Dx; csf

TB AND AIDSTB AND AIDS

Person with active TB are more Person with active TB are more frequent to have HIV than general frequent to have HIV than general populationpopulation

AIDS in HAITIANS: almost all children AIDS in HAITIANS: almost all children are positive for PPD --- active TB in are positive for PPD --- active TB in

60%60% New York: 50% of active TB patients New York: 50% of active TB patients

are HIV+are HIV+

Tb&AidsTb&Aids

Africans: 60% of active TB Africans: 60% of active TB patients are HIV+patients are HIV+

TB can appear at any stage of HIV TB can appear at any stage of HIV infectioninfection

But presentation varies with the But presentation varies with the stage: stage:

Tb&AidsTb&Aids

Early:Early:– Typical pattern of upper lobe infiltrate -Typical pattern of upper lobe infiltrate -

+cavitation …+cavitation … Late: Late:

– diffuse infiltrate .. no cavitation .. LNdiffuse infiltrate .. no cavitation .. LN Sputum is less frequent to be + for Sputum is less frequent to be + for

AFB with HIV than without.AFB with HIV than without. Extra pulmonary is more common … Extra pulmonary is more common …

40%40%

Tb&AidsTb&Aids

Pulmonary TB and HIV --- Pulmonary TB and HIV --- diagnosis is difficultdiagnosis is difficult– sputum (-) in 40 %sputum (-) in 40 %– atypical CXRatypical CXR– negative PPDnegative PPD

DIAGNOSISDIAGNOSIS

For any respiratory symptoms:For any respiratory symptoms: Do chest x-ray … if abnormal ---Do chest x-ray … if abnormal ---

– Sputum for :Sputum for : Zn stain Zn stain culture ..definite diagnosisculture ..definite diagnosis

– Use lowenstein-jansen mediaUse lowenstein-jansen media slow growth … 3 - 6 wksslow growth … 3 - 6 wks Bactic liquid media ...Bactic liquid media ...

DIAGNOSISDIAGNOSIS

PPD … intradermally …PPD … intradermally … 5 unit in o.1 ml 5 unit in o.1 ml 10 mm: 90 % infected10 mm: 90 % infected More than 15 mm: 100% infectedMore than 15 mm: 100% infected BCG and positive PPD:BCG and positive PPD: Unless very recent: positive PPD Unless very recent: positive PPD

of more than 10mm should not be of more than 10mm should not be due to BCGdue to BCG

DIAGNOSISDIAGNOSIS

Skin test- Mantoux testSkin test- Mantoux test

PPD injected in forearm PPD injected in forearm and examined 2-3 days and examined 2-3 days later later

Red welt around injection Red welt around injection indicates infection indicates infection

Examine medical history, Examine medical history, x-rays, and sputum x-rays, and sputum

DIAGNOSISDIAGNOSIS

False negative resultFalse negative result 20 % of active disease20 % of active disease MalnutritionMalnutrition SarcoidSarcoid Viral infectionViral infection SteroidSteroid PPD: is of limited value because PPD: is of limited value because

of of Low sensitivity and specificityLow sensitivity and specificity

TREATMENTTREATMENT

Chemotherapy: cure Chemotherapy: cure Isonised Isonised RifampicinRifampicin PyrazinamidePyrazinamide Ethambutol/streotomycinEthambutol/streotomycin

– rapidly reduce the number of viable rapidly reduce the number of viable organismorganism

– kill the bacillikill the bacilli– slow rate of induction of drug resistanceslow rate of induction of drug resistance

Treatment contTreatment cont

Drug failureDrug failure– none compliancenone compliance– in appropriate drugin appropriate drug– drug resistance drug resistance

INFECTION CONTROLINFECTION CONTROL

Active pulmonary tuberculosis:Active pulmonary tuberculosis:– Isolation of the patient Isolation of the patient – Isolation room should be negative Isolation room should be negative

pressurepressure– Patient remain until 3 negative Patient remain until 3 negative

smears and there is clinical smears and there is clinical improvementimprovement

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TUBERCULOSIS