Effects of Pathogen-Vector Interactions on the Transmission of Dengue Virus

From MicrobeWiki, the student-edited microbiology resource


Viral factors that affect DENV replication and transmission in the mosquito vector


Figure ?. a predicted RNA secondary structure of the 3’ NTR of a strain representing a less virulent American genotype strain, b a more virulent southeast Asian genotype [15]

The transmission of a particular strain of dengue from vector to host is determined by how infective the virus is in the vector, the level of viral replication in tissues of the vector, and how easily the virus can disseminate from the midgut to the salivary glands [4]. Infectivity, replication, and dissemination are affected by both the genotype of the infecting virus as well as a variety of mosquito host factors that modulate dengue virus infection.

More virulent strains have fast rates of viral replication as well as higher virus titers in both human host and vector host. It seems as though mutations within the E envelope glycoprotein responsible for virion binding to the host cell receptor increases the infectivity of a strain. Differences in the nontranslated regions of the genome (NTRs) also seem to affect virulence because possible changes in the time it takes to initiate translation because of changes in secondary structure as seen in figure (dengue virus structural… leitmeyer). No specific nucleotide or amino acid differences in either the coding or noncoding region have been correlated with attenuated disease in humans. It is only clear that there are differences at these sights between more virulent strains and less virulent strains.