Effects of Chikungunya virus titers in blood meals on virus infection, dissemination, and transmission in Asian tiger mosquito: Aedes albopictus (Diptera: Culicidae)

Abstract

Chikungunya virus (CHIKV) is an important mosquito-borne virus and transmission cycle of this virus
involves mosquito vectors and infected vertebrate hosts. However, the study about vector competence for CHIKV in
Thailand is limited. This study was conducted to examine the effects of CHIKV titers in blood meals on vector
competence of Aedes albopictus (Diptera: Culicidae). Five groups of Ae. albopictus were allowed to feed on different levels
of CHIKV in the blood meals which were 102, 103, 104, 105, and 106 CID50/ml of CHIKV. Body, legs and wings, and
saliva samples from blood-fed mosquitoes were assayed for the presence of CHIKV by using immunocytochemistry
staining on day 14 post blood feeding. Percent virus infection, dissemination, and transmission is defined as percent of
blood-fed mosquitoes with virus in their bodies, legs and wings, and saliva, respectively. The percent infections were
83.3, 90, 100, 100, and 100%, the percent disseminations were 70.8, 86.7, 100, 90, and 98%, and the percent transmissions
were 41.6, 70, 100, 90, and 82.4% after having been fed on 102, 103, 104, 105, and 106 CID50/ml of CHIKV, respectively.
However, there was no significant difference of the percent transmission after having been fed on 104 and 105 CID50/ml
of CHIKV. This study suggested that Ae. albopictus are susceptible for CHIKV infection and efficient vectors for CHIKV
transmission, and CHIKV titers in blood meals have effects on virus infection, dissemination, and transmission in Ae.
albopictus or vector competence of this mosquito.