Influence of Hosts on the Ecology of Arboviral Transmission: Potential Mechanisms Influencing Dengue, Murray Valley Encephalitis, and Ross River Virus in Australia

Abstract

Ecological interactions are fundamental to the transmission of infectious disease. Arboviruses are particularly elegant examples, where rich arrays of mechanisms influence transmission between vectors and hosts. Research on host contributions to the ecology of arboviral diseases has been undertaken within multiple subdisciplines, but significant gaps in knowledge remain and multidisciplinary approaches are needed. Through our multidisciplinary review of the literature we have identified five broad areas where hosts may influence the ecology of arboviral transmission: host immunity; cross-protective immunity and antibody-dependent enhancement; host abundance; host diversity; and pathogen spillover and dispersal. Herein we discuss the known and theoretical roles of hosts within these topics and then apply this knowledge to three epidemiologically important mosquitoborne arboviruses that occur in Australia: dengue virus (DENV), Murray Valley encephalitis virus (MVEV), and Ross River virus (RRV). We argue that the underlying mechanisms by which hosts influence arboviral activity are numerous and attempts to delineate these mechanisms further are needed. Investigations that focus on hosts of vector-borne diseases are likely to be rewarding, particularly where the ecology of vectors is relatively well understood. From an applied perspective, enhanced knowledge of host influences upon vector-borne disease transmission is likely to enable better management of disease burden. Finally, we suggest a framework that may be useful to identify and determine host contributions to the ecology of arboviruses.

Rôle des oiseaux sauvages dans la transmission et la dispersion des virus de l’influenza aviaire : apport de l’éco-épidémiologie dans les écosystèmes afro-tropicaux

“…Dans les régions tropicales africaines, en l'absence d'information épidémiologique, il a fallu mettre en place un cadre de recherche combinant les sciences de l'épidémiologie et de l'écologie (Caron et al, 2009). Ces travaux ont donc porté sur l'étude des processus écologiques qui sous-tendent les dynamiques de transmission des pathogènes au sein des populations ou des communautés d'hôtes (Plowright et al, 2008 ;Carver et al, 2009). Cette approche s'est structurée afin de comprendre : -quels sont les mécanismes de perpétuation des VIA FP chez les hôtes de maintenance que constituent les oiseaux sauvages ; -quelle est la capacité de dispersion des VIA par les espèces migratrices ; -quels sont les processus de transmission de ces virus à l'interface entre les oiseaux sauvages et la volaille.…”

Viral Evolutionary Ecology: Conceptual Basis of a New Scientific Approach for Understanding Viral Emergence

“…There are several lines of evidence on the relationship between natural ecosystems intervention and re/emergence of diseases produced by bacteria, parasites and viruses [32][33][34][35][36][37]. Specifically, for understanding viral emergence it is important to understand the sylvatic cycle of viruses, the transition to human populations, the relationship between vectors, pathogens and reservoirs in wildlife ecosystems, the change in the distribution of vectors and reservoirs after natural habitat fragmentation, and how these conditions are generating potential new roles and ecological niches for species.…”

“…Viruses exist in a high variety of ecosystems, in which numerous elements are implied in their trafficking and disease dynamics [80]. An important group of viruses implied in emergent and re-emergent diseases belong to the families Togaviridae (genus Alphavirus), Flaviviridae (genus Flavivirus) and Bunyaviridae (genera Orthobunyavirus and Phlebovirus) [32,[35][36][37]. These viruses are transmitted by haematophagous arthropods, mainly mosquitoes (Diptera: Culicidae).…”

“…These viruses are transmitted by haematophagous arthropods, mainly mosquitoes (Diptera: Culicidae). The family Culicidae of insect vectors is often associated with sylvatic areas, historically modified by human activities like artificial landscapes (agriculture, livestock, mining, house building and urbanization) [32,[35][36][37].…”

A Multi-Year Study of Mosquito Feeding Patterns on Avian Hosts in a Southeastern Focus of Eastern Equine Encephalitis Virus

“…1 Recent research has emphasized that some bird species are overused relative to their local availability by vector mosquitoes as blood-meal sources [2][3][4][5][6][7] and that overuse of certain avian species could influence the transmission of pathogens. 8 For example, temporal and spatial patterns of American robin ( Turdus migratorius ) abundance have been associated with variability of the rate of human cases of West Nile virus (WNV) and prevalence of WNV in mosquito populations. 6,9 Such patterns have been attributed to a higher rate of feeding on American robins by foraging mosquitoes relative to other avian species, 10 which leads to a higher probability of infection of robins, potentially causing robins to function as a superspreader of the virus.…”