Infectious diseases and tropical medicine for MRCPI Part 2

A 38-year-old man returns from two weeks in rural Nigeria with a 3-day history of fever, rigors and headache. He took no chemoprophylaxis. Blood film shows ring forms with a parasitaemia of 6%. He is confused and his lactate is 4.2 mmol/L. What is the most appropriate treatment?

1. Intravenous quinine and doxycycline Effective but second line. Quinine carries hypoglycaemia and cardiotoxicity risk and was shown inferior to artesunate for mortality.
2. Intravenous artesunate correct Correct. Confusion and a lactate above 4 with parasitaemia over 2% define severe falciparum malaria, and intravenous artesunate is superior to quinine on mortality. Treatment starts immediately, before species confirmation if necessary.
3. Chloroquine Wrong. Widespread chloroquine resistance in Plasmodium falciparum, particularly across West Africa, makes it unsafe.
4. Oral artemether–lumefantrine Wrong route for this severity. Oral artemisinin combination therapy is for uncomplicated malaria; a confused patient with lactic acidosis needs intravenous treatment and critical care input.
5. Primaquine Wrong for the acute illness. Primaquine clears dormant liver stages of vivax and ovale; falciparum has no hypnozoite stage, and G6PD testing is required first.

The point: Severe falciparum malaria: parasitaemia above 2%, impaired consciousness, acidosis, renal impairment, hypoglycaemia, ARDS. Intravenous artesunate, critical care, repeat films. Fever in a returning traveller is malaria until three films say otherwise.

Source: UK malaria treatment guidelines; HPSC Ireland malaria guidance Health Protection Surveillance Centre (Ireland) · tier 1, national regulator or guidance