Geography but not alternative host species explain the spread of raccoon rabies virus in Vermont

In North America, the raccoon-associated variant of rabies virus (RRV) is of special concern, given its relatively rapid spread throughout the eastern USA and its potential public health impact due to high raccoon host densities in urban areas. Northward expansion of this epizootic included an outbreak in the Canadian province of Quebec in 2006–2009 due to trans-border spread from the State of Vermont. To inform a more proactive approach to future control efforts, this study uses phylogenetic analyses to explore the role of geography and alternative carnivore hosts in the dynamics of RRV spread within Vermont. Specifically, we sought to examine whether striped skunks, a species frequently infected by RRV, could be part of the maintenance host community. Whole genome sequencing of 160 RRV samples from Vermont and neighbouring US states were used for fine-scale phylogeographic analyses. Results, together with the complete surveillance record of raccoon rabies since its entry into Vermont in 1994, document incursions by two distinct viral lineages and identify topographical features of the landscape which have significantly influenced viral spread, resulting in a complex distribution pattern of viral variants throughout the state. Results of phylogenetic cluster analysis and discrete state reconstruction contained some evidence of skunk-to-skunk and skunk-to-raccoon transmission but overall failed to support a role for skunks as alternative maintenance hosts

Improving adherence to medication in stroke survivors (IAMSS): a randomised controlled trial: study protocol

Background: Adherence to therapies is a primary determinant of treatment success, yet the World Health Organisation estimate that only 50% of patients who suffer from chronic diseases adhere to treatment recommendations. In a previous project, we found that 30% of stroke patients reported sub-optimal medication adherence, and this was associated with younger age, greater cognitive impairment, lower perceptions of medication benefits and higher specific concerns about medication. We now wish to pilot a brief intervention aimed at (a) helping patients establish a better medication-taking routine, and (b) eliciting and modifying any erroneous beliefs regarding their medication and their stroke. Methods/Design: Thirty patients will be allocated to a brief intervention (2 sessions) and 30 to treatment as usual. The primary outcome will be adherence measured over 3 months using Medication Event Monitoring System (MEMS) pill containers which electronically record openings. Secondary outcomes will include self reported adherence and blood pressure. Discussion: This study shall also assess uptake/attrition, feasibility, ease of understanding and acceptability of this complex intervention. Trial Registration: Current Controlled Trials ISRCTN3827495

Genome-wide diversity and phylogeography of Mycobacterium avium subsp. paratuberculosis in Canadian dairy cattle

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative bacterium of Johne’s disease (JD) in ruminants. The control of JD in the dairy industry is challenging, but can be improved with a better understanding of the diversity and distribution of MAP subtypes. Previously established molecular typing techniques used to differentiate MAP have not been sufficiently discriminatory and/or reliable to accurately assess the population structure. In this study, the genetic diversity of 182 MAP isolates representing all Canadian provinces was compared to the known global diversity, using single nucleotide polymorphisms identified through whole genome sequencing. MAP isolates from Canada represented a subset of the known global diversity, as there were global isolates intermingled with Canadian isolates, as well as multiple global subtypes that were not found in Canada. One Type III and six “Bison type” isolates were found in Canada as well as one Type II subtype that represented 86% of all Canadian isolates. Rarefaction estimated larger subtype richness in Québec than in other Canadian provinces using a strict definition of MAP subtypes and lower subtype richness in the Atlantic region using a relaxed definition. Significant phylogeographic clustering was observed at the inter-provincial but not at the intra-provincial level, although most major clades were found in all provinces. The large number of shared subtypes among provinces suggests that cattle movement is a major driver of MAP transmission at the herd level, which is further supported by the lack of spatial clustering on an intra-provincial scale

The impact of sheep breed on the risk of classical scrapie

The risk of classical scrapie in sheep is associated with polymorphisms in the prion protein (PrP) gene. In recent years, large-scale selective breeding programmes for sheep at lower risk of disease have been undertaken across the European Union. We analysed large-scale datasets on scrapie and sheep demography to investigate additional effects of sheep breed on scrapie risk. There was evidence for variation between certain breeds in the scrapie risk of some PrP genotypes, which could be caused by innate breed differences or distinct scrapie strains circulating within them. While the PrP genotypes of cases are generally consistent across breeds, some exceptions provide evidence that scrapie strain may influence affected PrP genotypes to a greater extent than innate breed differences. There was a significant association between the breed-level incidence of scrapie and the frequency of susceptible PrP genotypes in breeds. Our results lend support to selective breeding programmes which aim to reduce the frequency of high-risk PrP genotypes with measures not varying by sheep breed

What has molecular epidemiology ever done for wildlife disease research? Past contributions and future directions

The increasing availability of novel molecular techniques has transformed the study of human health and disease epidemiology. However, uptake of such approaches has been more conservative in the field of wildlife disease epidemiology. We consider the reasons for this and discuss current and potential applications of molecular techniques in a variety of relevant areas within the field of wildlife disease research. These include conducting wildlife disease surveillance, identifying sources of pathogen emergence, uncovering host-pathogen dynamics and managing current outbreaks, including the development and monitoring of wildlife vaccines. We highlight key examples of applications of molecular epidemiological approaches to wildlife disease scenarios and draw parallels from human disease research to suggest potential future directions. The potential value of next generation sequencing technologies to the field of wildlife disease research is discussed, and initial applications are highlighted, balanced against consideration of the challenges involved. Using a wide range of examples drawn from research into human, livestock and wildlife diseases, we demonstrate the value of using molecular epidemiological approaches at all scales of wildlife disease research, from pathogen strains circulating at a global scale to intra-individual host-pathogen dynamics. The potential future contribution of these technologies to the field of wildlife disease epidemiology is substantial. In particular, they are likely to play an increasingly important role in helping us to address a principal challenge in the management of wildlife diseases which is how to tease apart the transmission dynamics of complex multi-host systems in order to develop effective and sustainable interventions