TuberculosisDivya Mathew

Mr. X, 20 years old, presented to the medicine OPD with symptoms of fever for the last one month. He also complained of generalised tiredness and loss of appetite. He was surprised to note that in the last 1 month he had lost 5 kgs of weight. For the last 2 weeks he had also developed a productive cough that had not subsided despite antibiotics given to him by his treating physician.

On examination he was found to be afebrile, thinly built. General examination was otherwise unremarkable however auscultation of the chest revealed bronchial breath sounds in the right upper lobe.

Sputum AFB positive

Diagnosis???

Objectives Causative organismPathophysiologyPulmonary tuberculosisExtra pulmonary tuberculosisMDR, XDR TuberculosisDrugs first line, second line

Causative organismMycobacterium tuberculosisGenus mycobacteriumAcid fast bacillus mycolic acid resistant to gram staining Resists destaining by acid alcohol

Slow growth rate generation time of 20- 24 hours

Robert Koch discovered M.Tb in 1882

Estimated TB incidence rate, 2007:Source: WHO Geneva; WHO Report 2009: Global Tuberculosis Control; Surveillance, Planning and Financing

Pathophysiology Transmission airborne1-5 microns droplets

Pathogenesis MTB into lungs (or to cervical nodes or abdo. nodes)Replication of organismsPrimary complex (lung and mediastinal lymph nodes) Ghon complex

Mycobacteraemia with potential for seeding

Consequence of tuberculous infectionSymptomatic illness disease (minority)immunological control (majority) with Ghon focus on Xray.Infection is contained by granuloma but not eliminated

PathogenesisTuberculous disease is a consequence of:Primary infection e.g. in children

ReactivationnaturalAssociated with immunosupression

Re infection

Pulmonary tuberculosisLungs major site for primary infection and diseasePrimary tb-Fever Pleuritic chest pain- pleural effusionMyalgia, arthralgia, fatigue, weight loss

Reactivation- Fever, night sweatsAnorexiaCough productive or non productive

Apical posterior segment of upper lobe and superior segment of lower lobe.

Clinical manifestations

Clinical manifestationsPhysical examination:Thinly builtPallorLymphadenopathyBronchial breath sounds/ decreased breath sounds (pleural effusion)Fever +/-

Complications HemoptysisPneumothoraxExtensive pulmonary destruction

Miliary tuberculosisWide dissemination1-5 mm millet seed size of lesionsHematogenous spread

Multiorgan involvement Adrenal shock

Extra pulmonary tuberculosisSkin and soft tissueLymph nodesBones and jointsIntra abdominal structures includingPeritoneumKidneysAdrenalsLymph nodesCentral nervous systemTuberculomameningitis

tuberculous lymphadenitis

Potts spine

Renal tuberculosis

Tuberculomas

Skeletal tuberculosisTB involvement of the bonesand/orjoints10 to 35 percent of cases of extrapulmonary tuberculosis, 2 percent of TB cases overall

Potts spineTuberculous arthritis

Tuberculous spondylitis (Pott's disease) most common form of skeletal TBlower thoracic and upper lumbar regionInitially involving the anterior aspect of the intervertebral joint. Spreads behind the anterior ligament to involve the adjacent vertebral bodyEventually spreads into the intervertebral space

Avascular disc diesVertebral collapseGibbus deformityRisk of paraplegiaCold abscessSubacute course progressively worsening pain, muscle spasm, characteristic aldermans gait (short deliberate steps)

Arthritis Usually monoarticularTypically hip (most common) or kneeSwelling, pain, loss of joint function over weeks to months. Cold joint Constitutional symptoms not common.Synovial proliferation, joint effusion, erosion of cartilage and joint destruction.

diagnosis microscopy, culture of infected materialMedical treatment ATT duration uncertainIndications for surgery Spinal disease and advanced neurological deficitsWorsening neurological deficits while on ATTSpinal disease and kyphosis > 40 degrees at presentationChest wall cold abscess

Antituberculous agentsFirst line isoniazid, rifampicin, ethambutol, pyrazinamide

Drug resistant tuberculosisThe term "drug-resistant TB" refers to cases of TB caused by an isolate ofM. tuberculosisthat is resistant to one of the first-line anti-TB drugs:isoniazid,rifampin,pyrazinamide, ethambutol, or streptomycin.

The term "multidrug-resistant TB" (MDR-TB) refers to an isolate ofM. tuberculosisthat is resistant to at leastisoniazidandrifampinand possibly additional agents.

The term "extensively drug-resistant TB" (XDR-TB) refers to an isolate ofM. tuberculosisthat is resistant to at leastisoniazid,rifampin, and fluoroquinolones, as well as either aminoglycosides (amikacin,kanamycin) orcapreomycinor both

The term "totally drug-resistant TB" (TDR-TB) refers to an isolate ofM. tuberculosisresistant to all locally tested medications

Primary drug resistanceSecondary drug resistance

Summary Mycobacterium tuberculosisAirborne transmissionPrimary infection, latent disease, reactivation, reinfectionPulmonary, extraulmonary tuberculosisPotts spine/ tuberculous arthritis1st line and second line drugsDrug resistant tuberculosis

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