320.2 🩺 國考版

320.2.1 高頻考點

320.2.1.1 Diagnosis

  • AFB smear (Ziehl-Neelsen / auramine)
  • Culture (gold standard, 2-6 wk)
  • Xpert MTB/RIF NAAT (rapid + RIF resistance)
  • IGRA preferred for LTBI in BCG-vaccinated

320.2.1.2 Standard Treatment (DS-TB)

  • Intensive: RIPE × 2 months
  • Continuation: RI × 4 months
  • Total: 6 months
  • Extend to 9 months if cavitary + culture-positive at 2 mo

320.2.1.3 Drug Toxicities

  • R: orange fluids, hepatotoxicity, CYP induction
  • I: hepatotoxicity, peripheral neuropathy (B6), lupus
  • P: hepatotoxicity, hyperuricemia
  • E: optic neuritis (color vision check)
  • S: ototoxicity, nephrotoxicity

320.2.1.4 LTBI Regimens

  • 3HP (rifapentine + INH weekly × 12 wk) — preferred
  • 4R (rifampin × 4 mo) — INH intolerance
  • 3HR
  • 9H (older)

320.2.1.5 LTBI Indications

  • HIV
  • Recent contact
  • TNF-α inhibitor planned
  • Organ transplant
  • Risk factors

320.2.1.6 MDR-TB

  • Resistant to INH + RIF
  • BPaL (Bedaquiline + Pretomanid + Linezolid) × 6 months (Nix-TB 2020, ZeNix 2022)
  • BPaLM adds moxifloxacin (TB-PRACTECAL 2022)
  • WHO 2022 endorsement

320.2.1.7 Extrapulmonary TB

  • Lymphadenitis (scrofula)
  • Pleural (TB pleurisy, ADA > 40)
  • Meningitis (12 months + steroids)
  • Pericarditis (steroids)
  • Miliary (disseminated)
  • Pott’s disease (spine)
  • Genitourinary

320.2.1.8 HIV Co-Infection

  • ART + TB simultaneously
  • Within 2 weeks if low CD4
  • Rifabutin if drug interactions
  • IRIS in 10-30%; continue ART + steroids

320.2.1.9 TB + Pregnancy

  • Treat (untreated worse)
  • INH + RIF + EMB safe
  • Pyrazinamide avoid (debated)
  • Streptomycin contraindicated
  • Add pyridoxine

320.2.1.10 Key Trials

  • Nix-TB (2020): BPaL for MDR/XDR-TB
  • ZeNix (2022): optimized BPaL
  • TB-PRACTECAL (2022): BPaLM for MDR-TB

320.2.2 易混淆比范

Stage Symptoms TST/IGRA CXR Treatment
Exposed No Negative Normal Observe
LTBI No Positive Normal 3HP / 4R / 9H
Active TB Yes Positive Abnormal RIPE/RI

320.2.3 Special Topics

320.2.3.1 IRIS in HIV + TB

  • 10-30% of HIV-TB on ART
  • Worsening 4-8 weeks after ART start
  • Paradoxical (worsening of known) vs unmasking (new findings)
  • Continue ART + TB therapy
  • Steroids for severe

320.2.3.2 TB Pleural Effusion

  • ADA > 40 IU/L (high sensitivity)
  • Lymphocytic exudate
  • Pleural biopsy: granulomas
  • Treatment: standard 6-month
  • 65% recurrence in 5 years if untreated

320.2.3.3 TB Meningitis

  • High mortality (50%+)
  • Adjunctive corticosteroids (dexamethasone) ↓ mortality (BMT 2004)
  • 12 months treatment minimum
  • LP: lymphocytic + low glucose + high protein

320.2.3.4 Tuberculoma

  • Mass-like granuloma
  • Brain or lung
  • Standard TB regimen

320.2.3.5 TB Reactivation Risk Factors

  • HIV: 5-15% per year
  • TNF-α inhibitor: 5-10x
  • Renal failure: 25x
  • DM: 3-4x
  • Silicosis: 5x
  • Smoking: 2-3x