Effect of gametocyte sex ratio on infectivity of Plasmodium falciparum to Anopheles gambiae

V. Robert, A. F. Read, J. Essong, T. Tchuinkam, B. Mulder, J. P. Verhave, P. Carnevale

Research output: Contribution to journalArticlepeer-review

92 Scopus citations

Abstract

Insectary-reared Anopheles gambiae were experimentally fed with the blood of 90 naturally infected human volunteers carrying gametocytes of Plasmodium falciparum. At least one mosquito was successfully infected in 74% of experiments. The probability that a gametocyte carrier was infective, the probability that a mosquito became infected, and the number of oocysts harboured were related to gametocyte density. The mean proportion of male gametocytes was 0.217 (i.e., 3.6 females for every male). Sex ratios differed significantly between gametocyte carriers. Variation in sex ratio was not related to the probability that a gametocyte carrier was infective. Among infective people whose sex ratio estimates were based on a reasonable number of gametocytes, sex ratio significantly predicted the proportion of infected mosquitoes and mean oocyst load, with infectivity rising as the proportion of male gametocytes increased towards 50%. There was no indication that infectivity reached a peak at some intermediate sex ratio, as would be expected if random mating of gametes was the primary determinant of fertilization success. These results raise 2 interesting questions: why should higher sex ratios be more infective, and why is the observed population sex ratio lower than that: which produces the greatest infectivity?.

Original languageEnglish (US)
Pages (from-to)621-624
Number of pages4
JournalTransactions of the Royal Society of Tropical Medicine and Hygiene
Volume90
Issue number6
DOIs
StatePublished - 1996

All Science Journal Classification (ASJC) codes

  • Parasitology
  • Public Health, Environmental and Occupational Health
  • Infectious Diseases

Fingerprint Dive into the research topics of 'Effect of gametocyte sex ratio on infectivity of Plasmodium falciparum to Anopheles gambiae'. Together they form a unique fingerprint.

Cite this