Chemotherapeutic Strategies for Reducing Transmission of Plasmodium vivax Malaria - Advances in Parasitology - page 269

CHAPTER FIVE

Chemotherapeutic Strategies
for Reducing Transmission of
Plasmodium vivax Malaria

Nicholas M. Douglas * , † , ‡ , 1 , George K. John * , Lorenz von Seidlein † ,
Nicholas M. Anstey † , ‡ , Ric N. Price * , † , ‡
*Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford,
Oxford, UK
† Global Health Division, Menzies School of Health Research and Charles Darwin University,
Darwin, Australia
‡ Department of Infectious Diseases, Division of Medicine, Royal Darwin Hospital, Darwin, Australia
1 Corresponding author: Email: [e-mail]

Contents
1. Introduction 272

2. Transmissionof P. vivax 273

3. Reducing P. vivax TransmissionbyTreatingSymptomaticDisease 278

3.1. EradicatingBlood-StageParasites 279

3.2. Post-treatmentProphylaxis 281

3.3. EradicatingHypnozoites 282

4. Reducing P. vivax TransmissionUsingMassDrugAdministration 286

5. Conclusions 291

Abstract
Effective use of anti-malarial drugs is key to reducing the transmission potential of
Plasmodium vivax . In patients presenting with symptomatic disease, treatment with
potent and relatively slowly eliminated blood schizontocidal regimens administered
concurrently with a supervised course of 7 mg/kg primaquine over 7-14 days has
potential to exert the greatest transmission-blocking benefit. Given the spread of
chloroquine-resistant P. vivax strains,theartemisinincombinationtherapiesdihydroar-
temisinin + piperaquineandartesunate + mefloquinearecurrentlythemostassured
means of preventing P. vivax recrudescence. Preliminary evidence suggests that, like
chloroquine,thesecombinationspotentiatethehypnozoitocidaleffectofprimaquine,
butfurthersupportiveevidenceisrequired.Inviewofthehighrateof P. vivax relapse
followingfalciparuminfectionsinco-endemicregions,thereisastrongargumentfor
broadeningcurrentradicalcurepolicytoincludetheadministrationofhypnozoitocidal
dosesofprimaquinetopatientswith Plasmodium falciparum malaria.Themostimpor-
tant reservoir for P. vivax transmission is likely to be very low-density, asymptomatic