Experimental Infection of Culex (Culex) quinquefasciatus and Aedes (Stegomyia) aegypti with Wuchereria bancrofti

Abstract

A study was conducted to determine the susceptibility of local strains of Culex quinquefasciatus and Aedes aegypti to infection with the strain of Wuchereria bancrofti that occurs in Maceió. State of Alagoas, Brazil. Cx. quinquefasciatus blood fed simultaneously on the same microfilariae carrier ingested more blood and 2-3x more microfilariae than Ae. aegypti. Survival rates of both species of insects living for 21 days after blood feeding on microfilaraemic patients were not significantly different from the survival rates of mosquitoes that blood fed on amicrofilaraemic individuals. W. bancrofti parasites underwent normal development in Cx. quinquefasciatus, with third stage larvae first being recorded on the 11th day post infection, and their numbers increasing thereafter. Development of filariae in Ae. aegypti did not proceed beyond the first larval stage, and there was a progressively increasing number of non-viable larvae with the passage of time. It is concluded that Ae. aegypti is not involved in the transmission of W. bancrofti in Maceió.

Vector competence of Culex quinquefasciatus say from different regions of Brazil to Dirofilaria immitis

“…quinquefasciatus (Haiti and USA). Nevertheless, our values are similar to those observed by Calheiros et al (1998) who evaluated the experimental infection of a Brazilian strain of Cx. quinquefasciatus with W. bancrofti and reported 66% survival rate.…”

“…quinquefasciatus (Tables I, II). Calheiros et al (1998) infected Cx. quinquefasciatus with W. bancrofti and encountered three to 102 larvae (average 19.8 ± 19.5) in the midgut of 97% of mosquitoes dissected immediately after feeding on infected blood.…”

“…Moreover, there have been reports of vector competence differences between Cx. quinquefasciatus populations isolated from regions with various levels of prevalence of bancroftian filariasis (Janousek & Lowrie 1989, Brito et al 1997, Calheiros et al 1998. Could Cx.…”

Induction of actin gene expression in the mosquito midgut by blood ingestion correlates with striking changes of cell shape

“…Mosquitoes routinely ingest blood meals that exceed their own body weight (Calheiros et al, 1998). To accommodate this large volume of blood, the midgut inflates dramatically (Fig.…”

“…Ingestion of a blood meal also triggers a number of dramatic morphological and biochemical changes in the midgut epithelium. The volume of blood ingested by the mosquito is very large (2 to 3 ul; Calheiros et al,1998), in excess of its own body weight. Ingestion of a blood meal induces the secretion of the chitin-containing peritrophic matrix (PM), which is a thick acellular layer that completely surrounds the blood meal (Jacobs-Lorena and Oo, 1996;Tellam et al, 1999: Shao et al, 2001).…”