A 28-year-old woman from rural Odisha presents to the Primary Health Centre with fever, chills, and sweating for 3 days. Thick and thin blood smears are positive for Plasmodium vivax. She is not pregnant and has no contraindications to antimalarials. What is the most appropriate next step in management?

Explanation

## Management of Plasmodium vivax Malaria **Key Point:** P. vivax requires both schizonticide (to kill erythrocytic parasites) and hypnozoiticide (to prevent relapse from liver stages). ### Standard Treatment Regimen | Drug | Dose | Duration | Purpose | |------|------|----------|----------| | Chloroquine | 600 mg base stat, then 300 mg at 6, 24, 48 hrs | 3 days | Schizonticide (erythrocytic) | | Primaquine | 0.75 mg/kg/day (or 15 mg base daily) | 14 days | Hypnozoiticide (exoerythrocytic) | **High-Yield:** The standard first-line regimen for uncomplicated P. vivax in non-pregnant, non-G6PD-deficient individuals is chloroquine + primaquine. This patient has no contraindications mentioned, so treatment can begin immediately without delay. ### Why Primaquine is Essential 1. P. vivax forms dormant hypnozoites in the liver 2. Without primaquine, relapses occur in 40–50% of untreated patients 3. Primaquine is the only drug that eliminates hypnozoites 4. It must be given AFTER or concurrently with chloroquine to prevent severe haemolysis **Clinical Pearl:** In uncomplicated malaria from a non-endemic area, outpatient management with oral chloroquine + primaquine is standard. Referral to tertiary centre is reserved for severe malaria (cerebral, renal, pulmonary, shock, severe anaemia). **Warning:** G6PD testing is NOT mandatory before starting primaquine in all patients — it is recommended in populations with high G6PD prevalence (African, Mediterranean, Asian descent) or in patients with history of haemolysis. Since no such history is mentioned, treatment can proceed. However, counselling about risk of haemolysis should be done.