Project description:Zika virus (ZIKV) and chikungunya virus (CHIKV) are currently circulating in overlapping areas in the American continents and may both be transmitted by Aedes spp. mosquitoes. The first documented case, to the authors' knowledge, of sequential CHIKV and ZIKV infections diagnosed in a nonendemic area in a returning traveler is reported. The implications for heightened clinical surveillance for these infections and specific patient recommendations are emphasized.
Project description:Dengue virus type 2 was isolated from a tourist who returned from Borneo to Australia. Phylogenetic analysis identified this virus as highly divergent and occupying a basal phylogenetic position relative to all known human and sylvatic dengue virus type 2 strains and the most divergent lineage not assigned to a new serotype.
Project description:Human monocyte-derived macrophage cells were infected with Chikungunya virus (CHIKV) to identify and quantify intracellular transcriptional changes that contribute to the host response to infection with CHIKV. RNA was collected from these cells at 8 and 24 hours post-infection (hpi) and were compared to mock-infected cells. The RNAseq data was then analyzed to determine the genes, functions, and signaling pathways that were significantly affected in an effort to predict existing drugs that could be repurposed as potential therapeutics for CHIKV.
Project description:BackgroundAustralia is theoretically at risk of epidemic chikungunya virus (CHIKV) activity as the principal vectors are present on the mainland Aedes aegypti) and some islands of the Torres Strait (Ae. aegypti and Ae. albopictus). Both vectors are highly invasive and adapted to urban environments with a capacity to expand their distributions into south-east Queensland and other states in Australia. We sought to estimate the epidemic potential of CHIKV, which is not currently endemic in Australia, by considering exclusively transmission by the established vector in Australia, Ae. aegypti, due to the historical relevance and anthropophilic nature of the vector.Methodology/principal findingsWe estimated the historical (1995-2019) epidemic potential of CHIKV in eleven Australian locations, including the Torres Strait, using a basic reproduction number equation. We found that the main urban centres of Northern Australia could sustain an epidemic of CHIKV. We then estimated future trends in epidemic potential for the main centres for the years 2020 to 2029. We also conducted uncertainty and sensitivity analyses on the variables comprising the basic reproduction number and found high sensitivity to mosquito population size, human population size, impact of vector control and human infectious period.Conclusions/significanceBy estimating the epidemic potential for CHIKV transmission on mainland Australia and the Torres Strait, we identified key areas of focus for controlling vector populations and reducing human exposure. As the epidemic potential of the virus is estimated to rise towards 2029, a greater focus on control and prevention measures should be implemented in at-risk locations.
Project description:A woman who recently traveled to Thailand came to a local emergency department with a fever and papular rash. She was tested for measles, malaria, and dengue. Positive finding for IgM antibody against dengue and a failure to seroconvert for IgG against dengue for multiple blood samples suggested an alternate flavivirus etiology. Amplification of a conserved region of the non-structural protein 5 gene of the genus Flavivirus yielded a polymerase chain reaction product with a matching sequence of 99% identity with Zika virus. A urine sample and a nasopharygeal swab specimen obtained for the measles investigation were also positive for this virus by reverse transcription polymerase chain reaction. Subsequently, the urine sample yielded a Zika virus isolate in cell culture. This case report describes a number of novel clinical and laboratory findings, the first documentation of this virus in Canada, and the second documentation from this region in Thailand.
Project description:A kinetic analysis of host proteome modifications in the brain of CHIKV-infected mice sampled before and after the onset of clinical symptoms was performed. The combination of 2D-DIGE and iTRAQ proteomic approaches, followed by mass spectrometry protein identification, revealed 177 significantly differentially expressed proteins. This kinetic analysis was characterized by a dramatic down-regulation of proteins prior the appearance of the clinical symptoms followed by an increase expression of a large part of these proteins in the acute phase of symptoms. Bioinformatic analysis of the protein dataset allowed to identify major biological processes altered during the time course of CHIKV infection such as integrin signaling and cytoskeleton dynamics, endosome machinery and receptor recycling related to virus transport and synapse function, regulation of gene expression, and ubiquitin-proteasome pathway. This work gives new information on putative mechanisms that could be associated with severe neurological CHIKV infection-mediated disease. It also describes possible markers or targets that can be used to develop diagnostic and/or antiviral tools.