Febrile Jaundice with Acute Kidney Injury in a Malaria-Endemic Area
A 34-year-old rice farmer is brought to a district hospital with 6 days of fever, yellow eyes, dark urine and reduced urine output for 12 hours. He waded through flooded fields after heavy rain and has seen rats around the grain store. Temperature is 38.9°C, blood pressure 96/60 mmHg, pulse 112/min. He is jaundiced and has conjunctival suffusion and tender calves. Haemoglobin is 9.8 g/dL, white cell count 11.2 × 10⁹/L, platelets 78 × 10⁹/L; creatinine 310 µmol/L, urea 18 mmol/L, bilirubin 140 µmol/L, ALT 95 U/L, AST 120 U/L. Malaria rapid test is negative. Urine dipstick shows protein 2+ and red cells 10/high-power field. There is no dialysis on site; the referral hospital is 4 hours away. Blood cultures and leptospira testing are available but results take 48–72 hours.
1. What is your differential diagnosis, and which features make you most concerned?
Read the worked answer
The leading diagnosis is leptospirosis: he has fever, jaundice, acute kidney injury, thrombocytopenia, conjunctival suffusion, calf tenderness and a clear exposure history of wading in floodwater with rats nearby. The combination of jaundice and renal impairment with mild transaminase elevation fits Weil's disease better than acute viral hepatitis, which usually causes much higher transaminases and does not typically cause severe renal failure.
The differential includes:
- Severe malaria: a negative rapid test does not exclude it, especially if the test was stored badly or the patient has partially treated infection; thick and thin films are needed.
- Dengue: can cause fever, thrombocytopenia and bleeding, but jaundice and acute kidney injury are less typical.
- Sepsis from another source: cholangitis, pyelonephritis or bacteraemia can cause jaundice and renal impairment.
- Yellow fever or other viral haemorrhagic fever: possible in a febrile jaundiced patient with flood exposure, though conjunctival suffusion and calf tenderness point more to leptospirosis.
- Hepatitis A or E with acute kidney injury: less likely but should be tested.
What concerns me most is the oliguria, hypotension and rising creatinine in a setting without dialysis. He is at risk of hyperkalaemia, pulmonary oedema and death within days.
2. What immediate investigations and empiric treatment would you start, and how would you justify them?
Read the worked answer
I would take blood cultures before antibiotics, then start empiric treatment without waiting for leptospira results. The justification is that delayed antibiotics in severe leptospirosis increase mortality, while the tests take 48–72 hours.
Investigations:
- repeat malaria thick and thin films, not just a rapid test;
- blood cultures, urine culture, leptospira IgM or PCR, dengue NS1 and hepatitis A/E serology if available;
- full blood count, renal function, electrolytes, bicarbonate, clotting profile and blood gas if available;
- urine output monitoring and daily weight.
Treatment:
- Ceftriaxone intravenously is a reasonable choice for severe leptospirosis and also covers many causes of sepsis. Doxycycline is an alternative but must be used cautiously with renal impairment and is less suitable if the patient is vomiting.
- Give cautious isotonic fluids for hypovolaemia, but avoid overloading the kidneys; reassess after small boluses.
- Treat hyperkalaemia if present, avoid nephrotoxic drugs and adjust drug doses for renal function.
- Give antipyretics and monitor for bleeding.
I would not give empirical antimalarials solely because of the fever unless films are positive or the clinical picture strongly suggests malaria; however, in a malaria-endemic area with delayed microscopy, this decision should be individualised.
3. How would you decide whether to transfer him, given the 4-hour journey and limited ambulance?
Read the worked answer
The decision should be based on whether he is likely to need dialysis or develop a complication that cannot be managed locally. Persistent oliguria, a rising creatinine, hyperkalaemia, acidosis, encephalopathy, pulmonary oedema or shock are indications to transfer earlier rather than later. Waiting until he is too unstable for the journey increases risk.
If he is stable and making urine after initial fluids, it may be reasonable to observe for a few hours while arranging transport and repeating creatinine and potassium. If there is no improvement or he becomes anuric, transfer should be prioritised. Before transfer:
- stabilise glucose, temperature and blood pressure;
- treat hyperkalaemia with calcium gluconate, insulin and dextrose if needed;
- send blood cultures and leptospira samples with him;
- give the first dose of ceftriaxone and a clear referral note with urine output and creatinine trend;
- ensure the ambulance has oxygen and a staff member who can manage fluids.
If transfer is impossible, document the discussion with the family, continue conservative management and arrange the fastest possible outreach or teleconsultation. The decision is not 'transfer because the diagnosis is leptospirosis'; it is 'transfer because he may need renal replacement therapy and we cannot provide it'.