Article
The Influence of Dengue Virus Serotype-2 Infection on Aedes aegypti (Diptera: Culicidae) Motivation and Avidity to Blood Feed
Registro en:
FREITAS, Rafael Maciel de; et al. The Influence of Dengue Virus Serotype-2 Infection on Aedes aegypti (Diptera: Culicidae) Motivation and Avidity to Blood Feed. Plos One, v.8, n.6, e65252, 5p, 2013.
1932-6203
10.1371/journal.pone.0065252
Autor
Freitas, Rafael Maciel de
Sylvestre, Gabriel
Gandini, Mariana
Koella, Jacob C.
Resumen
Background: Dengue virus (DENV) is transmitted by Aedes aegypti, a species that lives in close association with human
dwellings. The behavior of DENV-infected mosquitoes needs further investigation, especially regarding the potential
influence of DENV on mosquito biting motivation and avidity.
Methodology/Principal findings: We orally challenged 4–5 day-old Ae. aegypti females with a low passage DENV serotype -
2 (DENV-2) to test whether the virus influences motivation to feed (the likelihood that a mosquito obtains a blood-meal and
the size of its blood meal) and avidity (the likelihood to re-feed after an interrupted first blood-meal). To assay motivation,
we offered mosquitoes an anesthetized mouse for 2, 3, 4 or 5 minutes 7 or 14 days after the initial blood meals and
measured the time they started feeding. 60.5% of the unexposed mosquitoes fed on the mouse, but only 40.5% of the
positive ones did. Exposed but negative mosquitoes behaved similarly to unexposed ones (55.0% feeding). Thus DENV-2
infection decreased the mosquitoes’ motivation to feed. To assay avidity, we offered the same mosquitoes a mouse two
hours after the first round of feeding, and we measured the time at which they started probing. The exposed (positive or
negative) mosquitoes were more likely to re-feed than the unexposed ones and, in particular, the size of the previous bloodmeal
that kept mosquitoes from re-feeding was larger in the exposed than in the unexposed mosquitoes. Thus, DENV-2
infection increased mosquito avidity.
Conclusions/Significance: DENV-2 significantly decreased the mosquitoes’ motivation to feed, but increased their avidity
(even after taking account the amount of blood previously imbibed). As these are important components of transmission,
we expect that the changes of the blood-feeding behaviour impact the vectorial capacity Ae. aegypti for dengue.