Diagnosis and Management of TB

John YatesConsultant Infectious Diseases

Diagnosis

• Generally sub-acute illness• Any persistent symptom may indicate active

tuberculosis• May be relatively mild• Any systemic symptoms – fever, weight loss,

night sweats, malaise, anorexia – increase suspicion

• Exposure history usually irrelevant if high risk ethnic background

Sites of infection• About 50/50 pulmonary/non-pulmonary• 24% extra-pulmonary LNs• 10% intra-throracic LNs• 10% pleural• 6% bone/joint ( 3% spine)• 5% GI• 3% CNS• 2% miliary• 1% GU• Others – skin, eye, breast,

Diagnosis- pulmonary

• Persistent cough +/- haemoptysis• Fever, weight loss, night sweats• Symptoms may be very mild• Usually stethoscope not useful• Breathlessness uncommon unless severe,

disseminated disease• May be asymptomatic• Main initial investigation – CXR• Referral to TB clinic

Diagnosis - pulmonary

• CXR• Sputum, if productive, x3 for smear and culture• Basic blood tests • HIV test• Mantoux/IGRA• CT to guide bronchoscopy/biopsy if unproductive• Broncho-alveolar lavage/induced sputum for

smear and culture• PCR for smear positive cases/difficult diagnoses

Early pulmonary disease

Patch of nodules

Early pulmonary disease

Late pulmonary disease

cavity

Lymphadenopathy

Asymmetrical hilar enlargement

Extra-pulmonary

• Cervical lymph nodes – mantoux +/- IGRA, biopsy for histology/culture

• Other sites imaging/biopsy• Multifarious presentations

• Main aid to diagnosis is suspicion• Don’t be put off by normal plain films of

chest/abdo/spine/bone

Extra-pulmonary

• Persistent symptoms > 2 weeks• +/- night sweats/weight loss/malaise• High risk ethnic backgrounds• Elevated ESR/CRP, normocytic anaemia, low

albumin

• Back pain, abdo pain, headache etc• Please refer to TB clinic

Diagnosis –extra pulmonary

• Immunological tests – negative in 10% active disease for mantoux

• Targeted imaging – but disease often multi-focal e.g. peritoneum, lymph nodes, spine, chest simultaneously

• Biopsy for histology, smear and culture

Abdominal TB

Ascites

Lymph node mass

Spinal TB

Increased soft tissue around L4/5

Management• Risk assessment for Multi-Drug Resistant -MDR TB – 1.5%

cases resistant to rifampicin and isoniazid• Smear positive cases sent for PCR for drug resistance • Isolation of smear positive cases for 2 weeks– usually at

home but in hospital if ill or unable due to shared accommodation/homelessness

• Initiate treatment – quadruple therapy –rifampicin/isoniazid/pyrazinamide, ethambutol or moxifloxacin

• Monitored treatment – TB nurses, clinic• Review with culture results• MDR cases referred to St George’s