Coronaviruses can infect a variety of animals including poultry, livestock, and humans and are currently classified into three groups. The interspecies transmissions of coronaviruses between different hosts form a complex ecosystem of which little is known. The outbreak of severe acute respiratory syndrome (SARS) and the recent identification of new coronaviruses have highlighted the necessity for further investigation of coronavirus ecology, in particular the role of bats and other wild animals. In this study, we sampled bat populations in 15 provinces of China and reveal that approximately 6.5% of the bats, from diverse species distributed throughout the region, harbor coronaviruses. Full genomes of four coronavirues from bats were sequenced and analyzed. Phylogenetic analyses of the spike, envelope, membrane, and nucleoprotein structural proteins and the two conserved replicase domains, putative RNA-dependent RNA polymerase and RNA helicase, revealed that bat coronaviruses cluster in three different groups: group 1, another group that includes all SARS and SARS-like coronaviruses (putative group 4), and an independent bat coronavirus group (putative group 5). Further genetic analyses showed that different species of bats maintain coronaviruses from different groups and that a single bat species from different geographic locations supports similar coronaviruses. Thus, the findings of this study suggest that bats may play an integral role in the ecology and evolution of coronaviruses.

Since an outbreak of severe acute respiratory syndrome (SARS) was averted in 2004, many novel coronaviruses have been recognized from different species, including humans. Bats have provided the most diverse assemblages of coronaviruses, suggesting that they may be the natural reservoir. Continued virological surveillance has proven to be the best way to avert this infectious disease at the source. Here we provide the first description of a previously unidentified coronavirus lineage detected from wild Asian leopard cats (Prionailurus bengalensis) and Chinese ferret badgers (Melogale moschata) during virological surveillance in southern China. Partial genome analysis revealed a typical coronavirus genome but with a unique putative accessory gene organization. Phylogenetic analyses revealed that the envelope, membrane, and nucleoprotein structural proteins and the two conserved replicase domains, putative RNA-dependent RNA polymerase and RNA helicase, of these novel coronaviruses were most closely related to those of group 3 coronaviruses identified from birds, while the spike protein gene was most closely related to that of group 1 coronaviruses from mammals. However, these viruses always fell into an outgroup phylogenetic relationship with respect to other coronaviruses and had low amino acid similarity to all known coronavirus groups, indicating that they diverged early in the evolutionary history of coronaviruses. These results suggest that these viruses may represent a previously unrecognized evolutionary pathway, or possibly an unidentified coronavirus group. This study demonstrates the importance of systematic virological surveillance in market animals for understanding the evolution and emergence of viruses with infectious potential.Since the severe acute respiratory syndrome (SARS) outbreak in early 2003, many new viruses of the family Coronaviridae have been identified in diverse host species, including birds, humans, and other mammals (7, 12-14, 18, 25, 27, 28, 29). Of these hosts, bats have provided the highest genetic diversity of novel coronaviruses (CoVs) (23,29). Analyses of the genomic organization and phylogenetic relationships of CoVs from bats and other host species indicate that bats are the likely natural reservoirs for all known CoVs from other hosts (23,26). This research also suggests that CoVs resident in bats may be introduced into other animals and subsequently become established in these hosts.Interspecies transmission of CoV from its natural reservoir to another species might result in disease outbreaks in naive hosts. The emerging pathway of SARS CoV in humans and market civets is an example of this (4, 5). Accumulated information has demonstrated that many SARS-like CoVs are harbored in bat species (12,13,23). However, the cross homologies between civet and human SARS CoV and bat SARS-like CoVs are still relatively low (about 92%), even in the most conserved regions of the replicase gene (13). Phylogenetic analyses and divergence dates of these CoVs indicate that the likely interme...

A pattern of serious injection drug user (IDU) driven HIV epidemics in Asia, with emerging evidence of generalization through heterosexual transmission, indicates the need for interventions focusing on both drug- and sex-related risk reduction. In a cross-border HIV prevention project for IDUs in northern Vietnam and southern China, peer educators disseminated risk reduction information to IDUs in the community and provided 20,000-25,000 sterile needles/syringes and 4,000-6,000 condoms per month. Since implementation of these interventions, the frequency of both injecting and sexual risk behaviours fell significantly, HIV prevalence among IDUs declined or stabilized, and HIV incidence dropped. There is official support for harm reduction interventions in both countries but this appears precarious in view of persistently powerful political and financial support for a law enforcement approach. Moreover, the simultaneous pursuit of inconsistent policies can have negative effects on the implementation of interventions. A harmonized and consistent policy environment is needed. Most of the evidence for efficacy of community-based HIV prevention comes from the developed world, but well-designed evaluations of such interventions in Asia and elsewhere in the developing world would have a better chance to influence policy decisions there. A synergistic approach to research, policy development, and service delivery is best calculated to achieve positive results in the struggle against HIV/AIDS in developing countries.