Plasmodium gallinaceum: comparative infection rates in Aedes aegypti and Anopheles quadrimaculatus.

Autor(es): Beasley S J

Resumo: The relative susceptibility of Aedes aegypti and Anopheles quadrimaculatus to Plasmodium gallinaceum infection was determined in experiments in which paired groups of the two species were fed on chicks with different levels of infection. Mosquito infections were described by the geometric mean of oocyst numbers in infected individuals and the percentage infection in a sample. These parameters were positively related in both species. When the geometric mean of oocyst numbers exceeded 40, A. aegypti manifested total susceptibility; infection incidence in A. quadrimaculatus was always lower than in a comparable group of A. aegypti and a portion of the anopheline population appeared refractory to infection. The changes in incidence, intensity and range of infection in mosquito samples fed at intervals during the course of patent chick infection are described. A. aegypti always had the higher incidence of infection and, in samples fed when gametocyte numbers were low, the infected culicines also had the greater range and intensity of infection. In samples fed at, or near, the peak of gametocytaemia, however, the range and mean of oocyst numbers in infected A. quadrimaculatus equaled or exceeded those in A. aegypti. Gametocyte infectivity declined for both species as gametocyte numbers increased in a developing chick infection and, for A. aegypti only, increased as gametocyte numbers declined in infections progressing to recovery. Transfer of a volume of heavily infected blood, by intravenous injection, to an uninfected chick immediately restored gametocyte infectivity for both species of mosquito. Increase and decrease in infectivity were both more markedly evidenced by changes in the level of A. aegypti infection.

Palavras-Chave: Plasmodium gallinaceum; Aedes aegypti; Anopheles quadrimaculatus; Malaria; Oocysts; Susceptibility; Gametocytes; Infectivity; Host-parasite relationsLife history; Mosquitoes; Protozoa

Imprenta: Experimental Parasitology, v. 32, n. 1, p. 11-20, 1972

Identificador do objeto digital: 10.1016/0014-4894(72)90004-5

Descritores: Aedes aegypti - Pathogenesis

Data de publicação: 1972