Fig 1.
JEV transmission cycle and potential inhibition through the introduction of Wolbachia-infected Cx. tritaeniorhynchus mosquitoes.
(A) The enzootic sylvatic cycle is maintained by reservoir bird hosts (cattle egrets and pond herons) in close association with Cx. tritaeniorhynchus mosquitoes in rice fields. JEV is amplified in pigs, and zoonotic infection occurs as a result of spillover events, but human-to-human transmission is not known to occur at significant levels. (B) The JEV transmission cycle could be interrupted at various points using a Wolbachia-based biocontrol strategy in which JEV-refractory mosquitoes are unable to maintain the enzootic transmission cycles or transmit the virus to humans.
Fig 2.
JEV genotypes, the geographical range of Cx. tritaeniorhynchus and secondary vectors.
(A) The five recognized genotypes of JEV (I–V) are shown in regions where the genotype (G) has been confirmed to be responsible for JE epidemics. (B) The areas in which the principal mosquito vector, Cx. tritaeniorhynchus, has been documented highlight the wide geographical range of this species of mosquito. (C) The distribution of some of the secondary vector species is shown within the JEV transmission zone.
Table 1.
Current and potential strategies for controlling Japanese encephalitis and the problems associated with each control method.
Fig 3.
Wolbachia phenotypic effects for mosquito biocontrol.
(A) Pathogen inhibition of DENV in Ae. aegypti by transinfected Drosophila Wolbachia strains significantly decreases the DENV infection levels in mosquitoes 14 days after an infectious blood meal. (B) Maternal transmission of Wolbachia from female mosquitoes to progeny is close to 100% for transinfected Drosophila strains in mosquitoes. (C) Wolbachia-induced reproductive phenotype cytoplasmic incompatibility in mosquitoes allowing rapid invasion of uninfected mosquito populations. (D) Fitness costs (e.g., fecundity) of transinfected Drosophila Wolbachia strains to Ae. aegypti, which impact the ability of some strains to invade mosquito populations. (A) and (D) are adapted from [50].
Table 2.
List of mosquito vector species infected with native or transinfected Wolbachia strains and their relative inhibitory effect on vector competence of arboviruses.