Plasmodium vivax Relapse Rates Following Plasmodium falciparum Malaria Reflect Previous Transmission Intensity

J Infect Dis. 2019 Jun 5;220(1):100-104. doi: 10.1093/infdis/jiz052.

Abstract

From 2003 through 2009, 687 of 2885 patients (23.8%) treated for Plasmodium falciparum malaria in clinical studies in Myanmar or on the Thailand-Myanmar border had recurrent Plasmodium vivax malaria within 63 days, compared with 18 of 429 patients (4.2%) from 2010 onward (risk ratio [RR], 0.176; 95% confidence interval, .112-.278; P < .0001). Corresponding data from 42 days of follow-up revealed that 820 of 3883 patients (21.1%) had recurrent P. vivax malaria before 2010, compared with 22 of 886 (2.5%) from 2010 onward (RR, 0.117; 95% CI, .077-.177; P < .0001). This 6-fold reduction suggests a recent decline in P. vivax transmission intensity and, thus, a substantial reduction in the proportion of individuals harboring hypnozoites.

Keywords: P. falciparum; P. vivax; Malaria; relapse.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Child
  • Female
  • Humans
  • Malaria, Falciparum / epidemiology*
  • Malaria, Falciparum / parasitology
  • Malaria, Vivax / epidemiology*
  • Malaria, Vivax / parasitology
  • Male
  • Myanmar / epidemiology
  • Plasmodium falciparum / pathogenicity*
  • Plasmodium vivax / pathogenicity*
  • Recurrence
  • Thailand / epidemiology