Forskning ved Københavns Universitet - Københavns Universitet

Forside

The differing impact of chloroquine and pyrimethamine/sulfadoxine upon the infectivity of malaria species to the mosquito vector

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • Høgh, Birthe
  • A Gamage-Mendis
  • G A Butcher
  • R Thompson
  • K Begtrup
  • C Mendis
  • S M Enosse
  • M Dgedge
  • J Barreto
  • W Eling
  • R E Sinden

Using serum or infected blood from Danish volunteers and Plasmodium falciparum-infected Mozambican patients, respectively, the impact of curative doses of chloroquine and pyrimethamine/sulfadoxine upon infectivity of P. falciparum to Anopheles arabiensis and An. gambiae or of P. berghei to An. stephensi was studied. Both treatments cleared circulating P. falciparum gametocytes within 28 days. Before this clearance, chloroquine enhanced infectivity to An. arabiensis, whereas pyrimethamine/sulfadoxine decreased infectivity. Patients harboring chloroquine-resistant parasites as opposed to -sensitive ones were 4.4 times more likely to have gametocytes following treatment. In contrast, pyrimethamine/sulfadoxine-resistant parasites were 1.9 times less likely to produce gametocytes. In laboratory infections using replicated P. berghei or P. falciparum preparations, serum from chloroquine-treated, uninfected, nonimmune volunteers enhanced gametocyte infectivity with increasing efficiency for 21 days following treatment, whereas pyrimethamine/sulfadoxine significantly suppressed infectivity. The observed enhancement in infectivity induced by the use of chloroquine combined with increased gametocytemias in chloroquine-resistant strains may in part explain the rapid spread of chloroquine resistance in endemic populations.

OriginalsprogEngelsk
TidsskriftAmerican Journal of Tropical Medicine and Hygiene
Vol/bind58
Udgave nummer2
Sider (fra-til)176-82
Antal sider7
ISSN0002-9637
StatusUdgivet - feb. 1998

ID: 202981889