Uncomplicated falciparum malaria — DTM&H MCQ

Correct answer: B — Uncomplicated falciparum malaria

The correct answer is B, uncomplicated falciparum malaria. Per the UK malaria treatment guidelines, severe or complicated disease is defined by specific clinical or laboratory thresholds: impaired consciousness, inability to tolerate oral intake, renal impairment (creatinine above 265 umol/L), acidosis (pH below 7.3), hypoglycaemia, pulmonary oedema, significant bleeding, or parasitaemia above 2 percent. This patient is alert, tolerating oral fluids, has a normal creatinine, a normal lactate of 1.8 mmol/L and a parasitaemia of only 0.4 percent, so she meets none of the severity criteria despite confirmed P. falciparum infection. She therefore has uncomplicated falciparum malaria and is suitable for oral artemisinin combination therapy (artemether-lumefantrine) with outpatient or short admission follow-up rather than parenteral treatment. Why the other options are wrong: E. Severe falciparum malaria: requires at least one severity marker such as impaired consciousness, acidosis, renal failure, hypoglycaemia, pulmonary oedema or parasitaemia over 2 percent, none of which are present here. C. Babesiosis: caused by Babesia species transmitted by ticks, not typically acquired in Côte d'Ivoire, and the blood film here explicitly shows P. falciparum, not intraerythrocytic Babesia forms. D. Dengue with warning signs: dengue is diagnosed by NS1 antigen or serology and presents with warning signs such as abdominal pain, persistent vomiting or bleeding; the positive falciparum blood film makes malaria the unifying diagnosis, not dengue. A. Relapsing P. vivax malaria: relapse is a feature of P. vivax and P. ovale due to hepatic hypnozoites, not P. falciparum, which does not form hypnozoites and does not relapse. Key point: Falciparum malaria is classified as uncomplicated only when no severity criteria (impaired consciousness, oral intolerance, renal impairment, acidosis, hypoglycaemia, pulmonary oedema, bleeding, or parasitaemia over 2 percent) are met, regardless of species confirmation.

Reference: PHE Advisory Committee on Malaria Prevention, UK malaria treatment guidelines 2016, Journal of Infection 72(6):635-649 (Box 3: severity criteria for falciparum malaria; parasitaemia threshold >2% red cells parasitised) - https://www.journalofinfection.com/article/S0163-4453(16)00047-5/fulltext