Robert Vincent, Read A.F., Essong J., Tchuinkam T., Mulder B., Verhave J.P., Carnevale Pierre. (1996). Effect of gametocyte sex ratio on infectivity of Plasmodium falciparum to Anopheles gambiae. Transactions of the Royal Society of Tropical Medecine and Hygiene, 90 (6), p. 621-624. ISSN 0035-9203.
Titre du document
Effect of gametocyte sex ratio on infectivity of Plasmodium falciparum to Anopheles gambiae
Année de publication
1996
Type de document
Article
Auteurs
Robert Vincent, Read A.F., Essong J., Tchuinkam T., Mulder B., Verhave J.P., Carnevale Pierre
Source
Transactions of the Royal Society of Tropical Medecine and Hygiene, 1996,
90 (6), p. 621-624 ISSN 0035-9203
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)
Plan de classement
Epidémiologie du paludisme [052ANOPAL03]
Descripteurs
PALUDISME ; VECTEUR ; INFESTATION ; AGENT PATHOGENE ; GAMETOGENESE ; CYCLE DE DEVELOPPEMENT ; SEX RATIO
