Early transmission of sensitive strain slows down emergence of drug resistance in Plasmodium vivax

The spread of drug resistance of Plasmodium falciparum and Plasmodium vivax parasites is a challenge towards malaria elimination. P. falciparum has shown an early and severe drug resistance in comparison to P. vivax in various countries. In fact, these Plasmodium species differ in their life cycle and treatment in various factors: development and duration of sexual parasite forms differ, symptoms severity are unequal, relapses present only in P. vivax cases, and the Artemisinin-based combination therapy (ACT) is only mandatory in all P. falciparum cases. We compared the spread of drug resistance for both species through two compartmental models using ordinary differential equations. The model structure describes how sensitive and resistant parasite strains infect a human population treated with antimalarials. We found that the early transmission before treatment and the low effectiveness of drug coverage support the prevalence of sensitive parasites delaying the emergence of resistant P. vivax . These results imply that earlier attention of symptomatic and reservoirs of P. vivax accelerates the spread of drug resistance as P. falciparum .