Infectious Diseases
This domain mixes global core content with Egyptian epidemiology: brucellosis, typhoid, hepatitis C, tuberculosis, and antimicrobial stewardship. Questions usually present a syndrome and ask for the single best diagnostic step or empirical regimen.
Sepsis and empirical therapy
- Sepsis is life-threatening organ dysfunction from infection; the sepsis bundle is blood cultures before antibiotics, broad-spectrum antibiotics within one hour in septic shock, lactate measurement, and 30 mL/kg crystalloid for hypotension or lactate of 4 mmol/L or more.
- Escalate to norepinephrine for persistent hypotension with a mean arterial pressure target of 65 mmHg.
- Adjust antibiotics to local resistance patterns, renal function, and culture results; de-escalate when possible.
CNS, tuberculosis and zoonoses
- Bacterial meningitis cerebrospinal fluid: high neutrophils, protein above 1 g/L, glucose ratio below 0.4, high opening pressure. Give dexamethasone with or before the first antibiotic dose in pneumococcal disease.
- Tuberculous meningitis: lymphocytes, very high protein, low glucose; treat empirically when suspicion is high and use polymerase chain reaction or culture.
- Brucellosis: undulant fever, sweats, sacroiliitis, exposure to unpasteurised dairy or livestock; diagnose with blood culture or serology and treat with doxycycline plus rifampicin or an aminoglycoside for six weeks or more.
Viral and vector-borne disease
- Acute hepatitis C is usually asymptomatic; chronic infection is diagnosed by RNA polymerase chain reaction and treated with direct-acting antivirals after assessing fibrosis.
- Infective endocarditis: take three sets of blood cultures before antibiotics, and use echocardiography; surgical referral for large vegetations, heart failure, or uncontrolled infection.
- Falciparum malaria with any danger sign needs intravenous artesunate, not oral therapy.
Worked example
A 34-year-old farmer has three weeks of fever, drenching sweats, low back pain and a painful sacroiliac joint, with normal white count and mildly raised transaminases. Blood cultures are taken, and the history reveals raw milk intake. Serology for Brucella is positive, so treatment is doxycycline plus rifampicin for at least six weeks, with a warning about relapse and adherence.
Traps
Delaying antibiotics in septic shock to complete imaging; treating purulent sputum alone as bacterial pneumonia; missing tuberculosis because the chest radiograph is normal; and using oral therapy in severe malaria.