Effectiveness of Artemether/Lumefantrine for the Treatment of Uncomplicated Plasmodium vivax and P. falciparum Malaria in Young Children in Papua New Guinea

Background. Artemisinin combination therapy is recommended as treatment for uncomplicated Plasmodium falciparum (Pf) malaria, whereas chloroquine is still widely used for non-Pf infections. A common treatment for both vivax and falciparum malaria would be welcome. Methods. A longitudinal prospective effectiveness study of 1682 children aged 3-27 months in outpatient clinics in Papua New Guinea. The main outcome was clinical treatment failure rate following treatment with artemether/lumefantrine (AL). Results. Among 5670 febrile episodes, 1682 (28%) had positive rapid diagnostic test (RDT) results and were treated with AL. A total of 1261 (22%) had an infection confirmed by blood slide examination. Of these, 594 Pv and 332 Pf clinical malaria cases were included in the primary effectiveness analysis. Clinical treatment failure rates at 7, 28, and 42 days were 0.2%, 2.2%, and 12.0%, respectively, for Pv and 0.3%, 1.2%, and 3.6%, respectively, for Pf. A single malaria-unrelated death occurred within 42 days following treatment with AL, in a child who was aparasitemic by blood slide at reattendance. Conclusions. AL provides a rapid clinical response against both Pf and Pv malaria, but is associated with a high rate of Pv recurrent clinical episodes between days 28 and 42. In order to prevent relapsing infections from long-lasting hypnozoites, AL should ideally be complemented with a course of primaquine. In the absence of better treatment and diagnostic options, the use of AL in young children in routine practice is an acceptable, interim option in coendemic areas where Pv is resistant to chloroquine and specific treatment for Pv hypnozoites not feasible.