Course 04: Respiratory Medicine and Infectious Disease
Lesson 7 of 14. Explore the diagnostic and management frameworks, work through the case, and finish the linked 10-question practice set. Urgent presentations require an emergency-care pathway and review of local professional scope.
Active TB suspicion and immediate actions
- Persistent cough, hemoptysis, weight loss, night sweats, fever, high-risk exposure or abnormal upper-lobe imaging raises concern for pulmonary TB.
- When infectious pulmonary TB is suspected, use appropriate airborne infection precautions and prompt public health/infectious disease assessment; routine surgical masks alone are not adequate for staff protection.
- Collect appropriate sputum specimens for AFB smear, culture and nucleic-acid amplification in accordance with local TB services.
Interpretation and latent infection
- IGRA and TST indicate immunologic sensitization but cannot distinguish active TB disease from latent infection; evaluate symptoms and radiography before latent-TB treatment.
- A negative smear or one negative NAAT does not invariably exclude TB; integrate clinical probability, imaging and culture.
- Risk of progression is higher with HIV, immunosuppression, recent exposure and certain comorbidities; screen before immunosuppressive therapy.
Treatment coordination and infection control
- Active TB requires multi-drug specialist-directed therapy, resistance testing, adherence support and public-health coordination.
- Review potential hepatotoxicity, drug-drug interactions including rifamycins, pregnancy and ongoing laboratory monitoring.
- Follow local protocols for contact investigation, reportability and de-isolation; do not declare an infectious patient noninfectious from an isolated test.
NTM and related differentials
- NTM may cause nodular/bronchiectatic or cavitary lung disease; isolation of NTM in one sample alone does not prove disease requiring treatment.
- Differentiate TB, NTM, fungal lung disease and malignancy according to clinical history, imaging and microbiology.
- Use culturally sensitive, confidential communication; avoid stigma when discussing migration, exposure, housing or treatment adherence.
Applied clinical case
A 41-year-old with 6 weeks of cough, weight loss and night sweats has an apical cavitary lesion and recent close TB contact.
Show model clinical reasoning and disposition
Suspect infectious active pulmonary TB. Arrange airborne precautions, specialist-directed sputum evaluation and public health notification according to local law; do not treat it as latent TB on the basis of a screening test.
Clinical self-check
- Can IGRA tell active from latent TB?
- What makes culture necessary?
- Who coordinates contact tracing?
Current guidance and further learning
- Canadian Tuberculosis Standards, eighth edition (external)
- Canadian Thoracic Society guideline library (external)