TY - JOUR
T1 - Brugia malayi microfilariae (Nematoda: Filaridae) enhance the infectivity of Venezuelan equine encephalitis virus to Aedes mosquitoes (Diptera: Culicidae)
AU - Vaughan, Jefferson A.
AU - Trpis, Milan
AU - Turell, Michael J.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1999/11
Y1 - 1999/11
N2 - We examined the potentially conflicting effects that microfilarial (MF) enhancement of viral infectivity and MF-induced mortality in mosquitoes have on the vectorial capacity of Aedes aegypti (L.), Aedes triseriatus (Say), and Aedes taeniorhynchus (Wiedemann) for Venezuelan equine encephalitis virus (VEE) when mosquitoes feed on gerbils co-infected with Brugia malayi (Buckley). Groups of mosquitoes were fed on gerbils that were either dually infected (VEE plus B. malayi MF) or singly infected (VEE only). Mosquito mortality was recorded daily, and 5-8 d later, surviving mosquitoes were assayed for disseminated viral infection. The contrasting effects of MF enhancement and MF-induced mortality differed among mosquito species and were determined by the nature and consequences of MF penetration through the mosquito midgut, but not to differences in mosquito susceptibilities to parenterally introduced virus. In Ae. aegypti, MF-induced mortality was high and tended to eliminate any significant effect of MF enhancement. In Ae. triseriatus, MF-induced mortality was low, and feeding on dually infected hosts resulted in 9 times as many mosquitoes with disseminated viral infections as did feeding on singly-infected hosts. In Ae. taeniorhynchus, MF-induced mortality was extremely high, yet under our experimental conditions, feeding on a dually infected hosts resulted in nearly 30 times as many disseminated infections as did feeding on singly infected hosts. The final outcome on vectorial capacity depended on the specific combination of MF, virus, and mosquito species involved. Therefore, future efforts toward understanding MF enhancement should be directed toward mosquito-virus-parasite species combinations that occur together in nature.
AB - We examined the potentially conflicting effects that microfilarial (MF) enhancement of viral infectivity and MF-induced mortality in mosquitoes have on the vectorial capacity of Aedes aegypti (L.), Aedes triseriatus (Say), and Aedes taeniorhynchus (Wiedemann) for Venezuelan equine encephalitis virus (VEE) when mosquitoes feed on gerbils co-infected with Brugia malayi (Buckley). Groups of mosquitoes were fed on gerbils that were either dually infected (VEE plus B. malayi MF) or singly infected (VEE only). Mosquito mortality was recorded daily, and 5-8 d later, surviving mosquitoes were assayed for disseminated viral infection. The contrasting effects of MF enhancement and MF-induced mortality differed among mosquito species and were determined by the nature and consequences of MF penetration through the mosquito midgut, but not to differences in mosquito susceptibilities to parenterally introduced virus. In Ae. aegypti, MF-induced mortality was high and tended to eliminate any significant effect of MF enhancement. In Ae. triseriatus, MF-induced mortality was low, and feeding on dually infected hosts resulted in 9 times as many mosquitoes with disseminated viral infections as did feeding on singly-infected hosts. In Ae. taeniorhynchus, MF-induced mortality was extremely high, yet under our experimental conditions, feeding on a dually infected hosts resulted in nearly 30 times as many disseminated infections as did feeding on singly infected hosts. The final outcome on vectorial capacity depended on the specific combination of MF, virus, and mosquito species involved. Therefore, future efforts toward understanding MF enhancement should be directed toward mosquito-virus-parasite species combinations that occur together in nature.
KW - Aedes aegypti
KW - Aedes taeniorhynchus
KW - Aedes triseriatus
KW - Arbovirus
KW - Filaria
KW - Microfilarial enhancement of arboviral transmission
UR - http://www.scopus.com/inward/record.url?scp=0033220008&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033220008&partnerID=8YFLogxK
U2 - 10.1093/jmedent/36.6.758
DO - 10.1093/jmedent/36.6.758
M3 - Article
C2 - 10593077
AN - SCOPUS:0033220008
SN - 0022-2585
VL - 36
SP - 758
EP - 763
JO - Journal of medical entomology
JF - Journal of medical entomology
IS - 6
ER -