Robert Vincent auteur aut IRD Read A.F. auteur aut IRD Essong J. auteur aut IRD Tchuinkam T. auteur aut IRD Mulder B. auteur aut IRD Verhave J.P. auteur aut IRD Carnevale Pierre auteur aut IRD text journalArticle eng text/pdf reformatted digital access 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 produced the greatest infectivity ? (Résumé d'auteur) specialized PALUDISME VECTEUR INFESTATION AGENT PATHOGENE GAMETOGENESE CYCLE DE DEVELOPPEMENT SEX RATIO CAMEROUN YAOUNDE 052ANOPAL03 90 6 621-624 1996 0035-9203 https://www.documentation.ird.fr/hor/fdi:010008052 10.1016/S0035-9203(96)90408-3 0035-9203 [F B010008052] https://www.documentation.ird.fr/hor/fdi:010008052 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_45-46/010008052.pdf IRD - Base Horizon / Pleins textes 1997-01-22 2006-06-06 fdi:010008052 fre