Korean J Parasitol.  2008 Jun;46(2):65-70. 10.3347/kjp.2008.46.2.65.

Gametocyte Clearance in Uncomplicated and Severe Plasmodium falciparum Malaria after Artesunate-Mefloquine Treatment in Thailand

• Tangpukdee N
• Krudsood S
• Srivilairit S
• Phophak N
• Chonsawat
• Yanpanich
• Kano S
• Wilairatana P

• KMID: 1089464
• DOI: http://doi.org/10.3347/kjp.2008.46.2.65

Abstract

Artemisinin-based combination therapy (ACT) is currently promoted as a strategy for treating both uncomplicated and severe falciparum malaria, targeting asexual blood-stage Plasmodium falciparum parasites. However, the effect of ACT on sexual-stage parasites remains controversial. To determine the clearance of sexual-stage P. falciparum parasites from 342 uncomplicated, and 217 severe, adult malaria cases, we reviewed and followed peripheral blood sexualstage parasites for 4 wk after starting ACT. All patients presented with both asexual and sexual stage parasites on admission, and were treated with artesunate-mefloquine as the standard regimen. The results showed that all patients were asymptomatic and negative for asexual forms before discharge from hospital. The percentages of uncomplicated malaria patients positive for gametocytes on days 3, 7, 14, 21, and 28 were 41.5, 13.1, 3.8, 2.0, and 2.0%, while the percentages of gametocyte positive severe malaria patients on days 3, 7, 14, 21, and 28 were 33.6, 8.2, 2.7, 0.9, and 0.9%, respectively. Although all patients were negative for asexual parasites by day 7 after completion of the artesunate-mefloquine course, gametocytemia persisted in some patients. Thus, a gametocytocidal drug, e.g., primaquine, may be useful in combination with an artesunate-mefloquine regimen to clear gametocytes, so blocking transmission more effectively than artesunate alone, in malaria transmission areas.

Keyword

Plasmodium falciparum; gametocyte clearance time; uncomplicated malaria; severe malaria; artemisinin-based combination therapy; Thailand

MeSH Terms

Adolescent
Adult
Animals
Antimalarials/*pharmacology/therapeutic use
Artemisinins/*pharmacology/therapeutic use
Drug Evaluation
Drug Therapy, Combination
Female
Follow-Up Studies
Germ Cells/*drug effects/growth & development
Humans
Malaria, Falciparum/*drug therapy/parasitology
Male
Mefloquine/*pharmacology/therapeutic use
Plasmodium falciparum/*drug effects/growth & development
Severity of Illness Index
Thailand
Treatment Outcome