A relapsed case of imported tertian malaria after a standard course of hydroxychloroquine and primaquine therapy

Abstract

Resistance of Plasmodium species to antimalarial agents has become increasingly challenging to the management and prevention of malaria. We experienced an imported case of tertian malaria due to Plasmodium vivax relapsed after a seemingly successful treatment with conventional course of hydroxychloroquine and primaquine. A 35-year-old man developed fever three days after return from India and mainland China. After his illness was diagnosed as tertian malaria, he was managed with hydroxychloroquine and then primaquine (primaquine base 15 mg/day for 14 days). Thereafter peripheral blood smears showed no malarial parasites, and there was no relapse of symptom until the 55th post-treatment day, however, six months after the above treatment tertian malaria relapsed. He was managed with the same medications again and malaria did not relapse for 10 months.

Clinical Characteristics of Vivax Malaria and Analysis of Recurred Patients

“…In our study, the rate of recurrence was 3.2%. Possible causes of recurrent episodes include resistance to chloroquine, recrudescence, resistance to primaquine, inadequate primaquine dose, low compliance with medication, and reinfection [14]. In the Republic of Korea, it is extremely difficult to make a distinction between recrudescence, relapse, and reinfection, since reinfection is always possible during malaria season.…”

“…In general, recrudescence, caused by failing to block the intra-erythrocyte life cycle of P. vivax , occurs within 4-5 weeks of treatment whereas relapse caused by extra-erythrocyte life cycle takes longer to occur than recrudescence [9]. If recurrence occurs after a period of 2-3 months, it is more likely to be related to primaquine administration rather than chloroquine resistance [14]. In this study, one patient after 32 days, 4 patients within 3 months, and 6 patients after 3 months of treatment respectively experienced recurrences, and all of those episodes were detected during malaria season, between May and October.…”

Chemoprophylaxis and the epidemiological characteristics of re-emergent P. vivax malaria in the Republic of Korea

“…[20][21][22][23][24] In this study, late primary attacks occurred in individuals who had received primaquine prophyt t laxis regularly, and it is thus possible that factors such as inadequate primaquine dosage and absorption are associated with P. vivax malaria. However, only 0.4% of those receiving the standard prophylactic dose of primaquine were rettreated for relapse, suggesting that primaquine effectively reduces the incit t dence of late primary attacks.…”

A trial for a DNA diagnosis of Plasmodium vivax malaria recently reemerging in the Republic of Korea using microtiter plate hybridization assay.

“…17 Genetic variations of Korean P. vivax have been strongly suggested because of its peculiar and atypical clinical manifestations (e.g., exceptionally long incubation periods, 3,21,22 atypical fever cycles, 3,23 and higher frequency of relapses. 3,[21][22][23][24] ). When human experimental infections were performed with the North Korean strain of P. vivax, 21 the incubation period was about one month in 25% of the patients and ranged between 5 and 13 months in the remaining 75% of the patients.…”