Efficacy of Primaquine in Preventing Short- and Long-Latency Plasmodium vivax Relapses in Nepal. (18th March 2019)

• Record Type: Journal Article
• Authors: Rijal, Komal Raj; Adhikari, Bipin; Ghimire, Prakash; Banjara, Megha Raj; Das Thakur, Garib; Hanboonkunupakarn, Borimas; Imwong, Mallika; Chotivanich, Kesinee; Day, Nicholas P J; White, Nicholas J; Pukrittayakamee, Sasithon
• Is Part Of: Journal of infectious diseases. Volume 220:Number 3(2019)
• Page Start: 448
• Page End: 456
• Publication Date: 2019-03-18
• Subjects: Plasmodium vivax -- relapse -- chloroquine -- primaquine -- Nepal; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiz126
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: Background: Plasmodium vivax is the main cause of malaria in Nepal. Relapse patterns have not been characterized previously. Methods: Patients with P. vivax malaria were randomized to receive chloroquine (CQ; 25 mg base/kg given over 3 days) alone or together with primaquine (PQ; 0.25 mg base/kg/day for 14 days) and followed intensively for 1 month, then at 1- to 2-month intervals for 1 year. Parasite isolates were genotyped. Results: One hundred and one (49%) patients received CQ and 105 (51%) received CQ + PQ. In the CQ + PQ arm, there were 3 (4.1%) recurrences in the 73 patients who completed 1 year of follow-up compared with 22 of 78 (28.2%) in the CQ-only arm (risk ratio, 0.146 [95% confidence interval, .046–.467]; P < .0001). Microsatellite genotyping showed relatively high P. vivax genetic diversity (mean heterozygosity, 0.843 [range 0.570–0.989] with low multiplicity of infection (mean, 1.05) reflecting a low transmission preelimination setting. Of the 12 genetically homologous relapses, 5 (42%) occurred in a cluster after 9 months, indicating long latency. Conclusions: Although there may be emerging CQ resistance, the combination of CQ and the standard-dose 14-day PQ regimen is highly efficacious in providing radical cure of short- and long-latency P. vivax malaria in Nepal. Abstract : Chloroquine and a standard-dose 14-day primaquine regimen for Plasmodium vivax malaria treatment in Nepal proved to be well tolerated and highly effective in preventing both short- and long-latency relapses.