Tropical and monsoon fevers

In the monsoon, a febrile patient with thrombocytopenia, jaundice, AKI or ARDS could have malaria, dengue, leptospirosis, scrub typhus or enteric fever, alone or together. Send the core tests, then start empirical ceftriaxone plus doxycycline (or azithromycin), with artesunate if malaria is not yet excluded.

Any severity criterion with asexual parasites (P. falciparum, and also P. vivax or knowlesi) = severe malaria: IV artesunate 2.4 mg/kg at 0, 12, 24 h then daily, followed by a full oral ACT course, plus glucose monitoring, careful fluids, and organ support.

Plasma leakage peaks in the critical phase around defervescence (days 3-7). Guide crystalloid by haematocrit, capillary refill, lactate and urine output; step fluids down quickly; avoid prophylactic platelets; and recognise reabsorption-phase overload.

After flood or sewage exposure: fever, myalgia, conjunctival suffusion, then jaundice, non-oliguric hypokalaemic AKI, pulmonary haemorrhage and myocarditis. Give penicillin G or ceftriaxone early; dialyse early; lung-protective ventilation for pulmonary haemorrhage.

Orientia tsutsugamushi infection with fever, eschar and lymphadenopathy that can progress to ARDS, AKI, shock, myocarditis and meningoencephalitis. Severe disease: IV doxycycline plus azithromycin for 7 days (INTREST).

Complicated enteric fever (encephalopathy, shock, perforation, GI bleeding) needs IV ceftriaxone (or azithromycin combination), blood cultures before antibiotics, and early surgical review for perforation. Fluoroquinolone resistance is high in India.