Short Course Radical Cure of P. Vivax Malaria in Nepal

Plasmodium vivax is associated with recurrent infections weeks or months following the acute infection due to reactivation of dormant liver stages. Recurrent infections can be associated with a febrile illness, cumulative risk of severe anaemia, direct and indirect mortality, and are the most important source of onward transmission of the parasite.

In co-endemic areas, there is a very high risk (up to 50%) of patients representing with P.vivax malaria following treatment of P falciparum. Hence, in co-endemic regions there is a strong rationale for eradicating P.vivax hypnozoites from the liver in patients presenting with uncomplicated P. falciparum infections.

The recently completed multicentre IMPROV study compared the efficacy of a 7 day PQ regimen (1.0mg/kg/day for 7 days) with a 14 day regimen (0.5mg/kg/day for 14 days). The 7 day PQ regimen was non-inferior to the 14 day regimen and 5 times more efficacious at reducing P.vivax recurrence than the control.

This study is designed as a multicentre randomized, open label trial to assess the safety and efficacy of a low dose short course PQ treatment (3.5mg/kg total dose given over 7 days) in G6PD normal patients with P.vivax and P falciparum to reduce the risk of subsequent P.vivax episodes.

Inclusion criteria

• P. falciparum and/or vivax infection
• Fever (axillary temperature ≥37.5⁰C) or history of fever in preceding 48 hours
• Age >1 years
• G6PD normal by Rapid Diagnostic Test (RDT) as per national guidelines
• Written informed consent
• Able to comply with all study procedures and timelines

Exclusion criteria

• General danger signs or symptoms of severe malaria
• Anaemia, defined as Hb <8g/dl
• Pregnant women as determined by Urine β-HCG pregnancy test
• Breast feeding women
• Known hypersensitivity to any of the drugs given
• Regular use of drugs with haemolytic potential
• Blood transfusion within the last 4 months