Epidemic host community contribution to mosquito-borne disease transmission: Ross River virus

Abstract

Most vector-borne diseases infect multiple host species, but disentangling the relative importance of different host species to transmission can be complex. Here we study how host species' abundance and competence (duration and titre of parasitaemia) influence host importance during epidemic scenarios. We evaluate this theory using Ross River virus (RRV, family Togaviridae, genus Alphavirus), a multi-host mosquito-borne disease with significant human health impacts across Australia and Papua New Guinea. We used host contribution models to find the importance of key hosts (possums, wallabies, kangaroos, horses, humans) in typical mammal communities around five Australian epidemic centres. We found humans and possums contributed most to epidemic RRV transmission, owing to their high abundances, generally followed by macropods. This supports humans as spillover hosts, and that human-mosquito and possum-mosquito transmission is predominant during epidemics. Sensitivity analyses indicate these findings to be robust across epidemic centres. We emphasize the importance of considering abundance and competence in identifying key hosts (during epidemics in this case), and that competence alone is inadequate. Knowledge of host importance in disease transmission may help to equip health agencies to bring about greater effectiveness of disease mitigation strategies.

Modulation of Monocyte-Driven Myositis in Alphavirus Infection Reveals a Role for CX 3 CR1 + Macrophages in Tissue Repair

“…KEYWORDS inflammation, macrophages, microparticles, myositis, Ross River virus, tissue repair, viral infection A rthritogenic alphaviruses, including Ross River virus (RRV) and Chikungunya virus (CHIKV), are mosquito-borne viruses that cause severe inflammatory musculoskeletal illnesses (1). RRV is endemic in various regions of Australia, and its distribution is broadening (2,3), while CHIKV is distributed globally and causes recurrent pandemics involving millions of people (4)(5)(6). These alphavirus infections are associated with acute myositis and musculoskeletal tissue inflammation (e.g., joints, muscle, and bone) during systemic spread in the host, resulting in debilitating symptoms, including myalgia and arthralgia (7)(8)(9).…”

Spatial and temporal patterns of Ross River virus in South East Queensland, Australia: identification of hot spots at the rural-urban interface

“…Although male to female prevalence ratios have varied slightly in previous studies, no overall gender-related risk has been apparent (3,8). Clinical studies report that children show fewer symptoms than adults, presumably due to age-related differences in immune responses, while symptoms tend to persist longer in adults (8,11,41,42 (57,58).…”

Spatial and temporal patterns of Ross River virus in South East Queensland, Australia: identification of hot spots at the rural-urban interface

“…However, variations in weather patterns and vector-host ecology mean that climate-based predictions are only valid locally or, at best, regionally, rather than nationally (55,56). Hence, although suitable weather conditions are a requisite precursor to outbreaks, outbreak occurrence ultimately depends on availability of, and interactions between, sufficient competent vectors and susceptible hosts (57,58).…”