Antirelapse Efficacy of Various Primaquine Regimens for Plasmodium vivax.

D D Rajgor,M S Parulekar,N A Kshirsagar,N J Gogtay,V S Kadam,M M Kocharekar,S S Dalvi,A B Vaidya

doi:10.1155/2014/347018

D D Rajgor, M S Parulekar + Show 6 more

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https://doi.org/10.1155/2014/347018

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Abstract

Background. Efficacy of standard dose of primaquine (PQ) as antirelapse for P. vivax has decreased. We aimed to assess efficacy of different PQ regimens. Methods. It was an open label, randomized, controlled, parallel group, assessor blind study comparing antirelapse efficacy of 3 PQ regimens (B = 15 mg/day × 14 days, C = 30 mg/day × 7 days, and D = 30 mg/day × 14 days) with no PQ group (A) in P. vivax patients. Paired primary and recurrence samples were subjected to 3 methods: (i) month of recurrence and genotyping, (ii) by PCR-RFLP, and (iii) PCR sequencing, to differentiate relapse and reinfection. The rates of recurrence relapse and reinfection were compared. Methods were compared for concordance between them. Results. The recurrence rate was 16.39%, 8.07%, 10.07%, and 6.62% in groups A, B, C, and D, respectively (P = 0.004). The relapse rate was 6.89%, 1.55%, 4%, and 3.85% as per the month of recurrence; 8.2%, 2%, 4.58%, and 3.68% (P = 0.007) as per PCR-RFLP; and 2.73%, 1.47%, 1.55%, and 1.53% as per PCR sequencing for groups A, B, C, and D, respectively. The concordance between methods was low, 45%. Conclusion. The higher recurrence rate in no PQ as compared to PQ groups documents PQ antirelapse activity. Regimens tested were safe. However, probable resistance to PQ warrants continuous monitoring and low concordance and limitations in the methods warrant caution in interpreting.

Highlights

Malaria continues to be a major global health problem exposing over 2000 million of the world’s population to varying degrees of malaria risk
Of the four parasite species, P. falciparum, P. vivax, P. malariae, and P. ovale that cause malaria, P. falciparum and P. vivax are the two major parasite species seen in the country, India
The focus of research in malaria has centered around P. falciparum because of the development of resistance by this species to the standard antimalarial drugs and the mortality associated with the species

Summary

Introduction

Malaria continues to be a major global health problem exposing over 2000 million of the world’s population to varying degrees of malaria risk. In the city of Mumbai, P. vivax accounts for 80% of the total malaria cases [2]. Despite this burden, P. vivax species remains less well studied. It was an open label, randomized, controlled, parallel group, assessor blind study comparing antirelapse efficacy of 3 PQ regimens (B = 15 mg/day × 14 days, C = 30 mg/day × 7 days, and D = 30 mg/day × 14 days) with no PQ group (A) in P. vivax patients. The relapse rate was 6.89%, 1.55%, 4%, and 3.85% as per the month of recurrence; 8.2%, 2%, 4.58%, and 3.68% (P = 0.007) as per PCR-RFLP; and 2.73%, 1.47%, 1.55%, and 1.53% as per PCR sequencing for groups A, B, C, and D, respectively. Probable resistance to PQ warrants continuous monitoring and low concordance and limitations in the methods warrant caution in interpreting

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