Infectious Diseases and Tuberculosis
Infectious disease questions test a structured approach: identify the syndrome, assess severity, choose empiric therapy based on likely pathogens and local resistance, then narrow therapy with culture results. Candidates must know the principles of antimicrobial stewardship, the difference between colonization and infection, and the red flags for sepsis. Tuberculosis requires specific knowledge: screening, diagnostic methods, the distinction between latent and active disease, and treatment principles including adherence and drug interactions. Understand the approach to fever of unknown origin and to needle-stick or exposure prophylaxis.
Traps: treating colonization (for example, asymptomatic bacteriuria) as infection; choosing broad-spectrum antibiotics before cultures are taken; missing tuberculosis because the chest radiograph is atypical; forgetting drug interactions in tuberculosis treatment.
Worked example: a patient with fever, cough, weight loss, and an abnormal chest radiograph. Sputum testing for tuberculosis is indicated, and isolation precautions begin before results return. Do not start empiric antibacterial therapy and discharge the patient without considering tuberculosis.
Rule of thumb: take cultures before antibiotics whenever feasible, and reassess therapy at 48-72 hours. De-escalation is as important as escalation.
Key concepts: syndrome-based empiric therapy, stewardship, sepsis recognition, latent versus active tuberculosis, and exposure prophylaxis.