No abstract

Reported for the first time in 1955 in Malaysia, Tembusu virus (TMUV) remained, for a long time, in the shadow of flaviviruses with human health importance such as dengue virus or Japanese encephalitis virus. However, since 2010 and the first large epidemic in duck farms in China, the threat of its emergence on a large scale in Asia or even its spillover into the human population is becoming more and more significant. This review aims to report current knowledge on TMUV from viral particle organization to the development of specific vaccines and therapeutics, with a particular focus on host–virus interactions.

The expression of the Siglec family of molecules by hematopoietic cells from uninfected and SIV infected disease susceptible rhesus macaques (RM) and SIV infected disease resistant sooty mangabeys (SM) and for comparison humans was carried out. The predominant cell lineage in all 3 species expressing Siglec's was monocytes. The major finding by both a cross sectional and a prospective SIV infection study showed that whereas monocytes from RM show marked increase in each Siglec constitutively expressed, monocytes from SM showed marked decreases in Siglec-1 expression. While monocytes from all 3 species constitutively expressed Siglec-3, human monocytes in addition expressed Siglec-5 and 9 and to a lower density 7, monocytes from RM expressed Siglec-7 and those from SM expressed Siglec-1. Monocytes from all 3 species however expressed mRNA for Siglec's-1, 5, 7 and 9. The reasons for the failure to detect these molecules at the protein level and the mechanisms for such distinct effects of SIV infection on Siglec expression are discussed.

Among emerging zoonotic pathogens, mosquito-borne viruses (MBVs) circulate between vertebrate animals and mosquitoes and represent a serious threat to humans via spillover from enzootic cycles to the human community. Active surveillance of MBVs in their vectors is therefore essential to better understand and prevent spillover and emergence, especially at the human–animal interface. In this study, we assessed the presence of MBVs using molecular and phylogenetic methods in mosquitoes collected along an ecological gradient ranging from rural urbanized areas to highland forest areas in northern Thailand. We have detected the presence of insect specific flaviviruses in our samples, and the presence of the emerging zoonotic Tembusu virus (TMUV). Reported for the first time in 1955 in Malaysia, TMUV remained for a long time in the shadow of other flaviviruses such as dengue virus or the Japanese encephalitis virus. In this study, we identified two new TMUV strains belonging to cluster 3, which seems to be endemic in rural areas of Thailand and highlighted the genetic specificities of this Thai cluster. Our results show the active circulation of this emerging flavivirus in Thailand and the need for continuous investigation on this poorly known but threatening virus in Asia.