Management of Uncomplicated Plasmodium vivax Malaria in a Pregnant Patient With G6PD Deficiency.

Plasmodium vivax is one of the most common forms of malaria worldwide, notable for its ability to relapse from a dormant liver stage. Radical cure of Plasmodium as well as with P. ovale requires the use of 8-aminoquinolines to clear both blood and liver parasites; however, they are contraindicated in glucose-6-phosphate dehydrogenase (G6PD) deficiency due to the risk of causing hemolysis and in pregnant individuals due to the unknown G6PD status of the fetus.  We present a case of a young pregnant woman with fever, nausea, and vomiting, who, upon blood peripheral smear and polymerase chain reaction (PCR) confirmation, was diagnosed with Plasmodium vivax. In this case, standard radical cure was not feasible during pregnancy, and a seven-day course of quinine and clindamycin was initiated for treatment of the acute blood-stage infection while G6PD results were awaited. Upon discharge, the patient was unable to obtain the medication and returned two months later with relapsing fevers, abdominal pain, and chills. Given presumed chloroquine-sensitive Plasmodium vivax, chloroquine remains the preferred agent for suppressive therapy during pregnancy. However, hydroxychloroquine was subsequently selected due to its more favorable side effect profile and improved tolerability for prolonged use. Both agents are considered safe in pregnancy. Before initiating treatment, G6PD screening is essential, as many antimalarial agents can precipitate hemolysis; quantitative testing is particularly important to distinguish deficiency from intermediate activity in heterozygous females. This case underscores the complexities of managing P. vivax infection in overlapping contraindications. It highlights the critical role of early and precise G6PD assessment, with quantitative assays in females being particularly essential, to inform safe administration of antimalarial therapy. These findings emphasize the necessity of individualized management strategies, especially for vulnerable migrant populations, and the importance of a structured follow-up plan to prevent relapse and ensure the delivery of definitive treatment.