Plasmodium vivax malaria relapses at a travel medicine centre in Rio de Janeiro, a non-endemic area in BrazilPosted: July 30, 2012
Twenty-one relapses (39.6%) of P.
vivax malaria were observed. The overall median time to relapse, obtained by the Kaplan-Meier method, was 108 days, and the survival analysis demonstrated an association between non-weight-adjusted primaquine dosing and the occurrence of relapse (p<0.03).
Primaquine total dose at 3.6mg/kg gave improved results in preventing relapses.
Conclusions: A known challenge to individual cure and environmental control of malaria is the possibility of an inappropriate, non-weight-based primaquine dosing, which should be considered a potential cause of P. vivax malaria relapse.
Indeed, the total dose of primaquine associated with non-occurrence of relapses was higher than recommended by Brazilian guidelines.