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Lyme disease is the most prevalent vector-borne disease in north temperate areas worldwide, with the majority of cases reported in the northeastern United States. The transmission cycle involves ticks, deer, small mammalian hosts such as mice, and numerous other species. Levi et al. (2012) suggested that Canis latrans (Coyote) abundance and Vulpes vulpes (Red Fox) scarcity are strong predictors of Lyme disease cases in eastern North America, with Odocoileus virginianus (White-tailed Deer) abundance being less important. This suggestion was based on correlations of disease dynamics with human harvests of canids, as it has been suggested that Red Foxes occur at a lower abundance because of Coyote predation. Because Red Foxes are more effective predators of small mammals, the authors of that work contend that the lower Red Fox abundance results in an increase in the incidence of Lyme disease. This paper re-examines the evidence used by Levi at al. (2012) to reach their conclusions. We address the following points: 1) Levi et al. did not provide data on rodent populations or Lyme disease incidence; 2) Coyotes eat rodents, so a Coyote-induced reduction of Red Fox populations might not result in increased rodent populations; 3) Coyote harvests are poor indicators of Coyote abundance; 4) both Red Fox numbers and rodent numbers fluctuate dramatically due to factors such as disease and weather; 5) some of the data used by Levi et al. (2012) were from regions with western Coyotes, while other data were from areas with hybrid eastern Coyotes, thus confounding the situation; and 6) Levi et al. did not consider important alternative hypotheses, such as habitat fragmentation and climate change. Additionally, the historical dynamics of the Lyme disease system are unknown given that Canis lupus lycaon (= Canis lycaon) (Eastern Wolf) and Urocyon cinereoargenteus (Gray Foxes) originally lived in most of the northeast, while Red Foxes and Coyotes were historically absent from most of the area. We suggest proceeding with caution before concluding that the presence of Coyotes (or the reduction of Red Foxes) is the primary cause of increased incidence of Lyme disease cases in the eastern United States. [ABSTRACT FROM AUTHOR]

Abstract: The entire genome of a mid-Atlantic raccoon strain rabies virus (RRV) isolated in Canada was sequenced; this is the second North American wildlife rabies virus isolate to be fully characterized. The overall organization and length of the genome was similar to that of other lyssaviruses. The nucleotide sequence identity of the raccoon strain ranged between 32.7% and 85.0% when compared to other lyssaviruses, while the deduced amino acid sequence identity ranged between 22.9% and 94.2% with the nucleoprotein and polymerase being the most conserved. Notable features of RRV include the phosphoprotein''s four amino acid extension compared to most other rabies viruses, and a nucleotide substitution immediately prior to the normal start codon that results in an additional methionine at the beginning of the L protein. This is the first report of the RRV L gene sequence and its 2128 amino acid product. Rates of non-synonymous and synonymous nucleotide changes within the lyssavirus L gene identified the conserved blocks II, III and IV as being most constrained. Analysis of L gene codon substitution patterns favoured models that supported positive selection, but only one site, corresponding to Leu62 of the RRV L protein, was identified as being under weak positive selection. [Copyright &y& Elsevier]

Abstract: Landscape barriers influence movement patterns of animals, which in turn, affect spatio-temporal spread of infectious wildlife disease. We compare genetic data from computer simulations to those acquired from field samples to measure the effect of a landscape barrier on raccoon (Procyon lotor) movement, enabling risk assessment of raccoon rabies disease spread across the Niagara River from New York State into Ontario, an area currently uninfected by rabies. An individual-based spatially explicit model is used to simulate the expansion of a raccoon population to cross the Niagara River, for different permeabilities of the river to raccoon crossings. Since the model records individual raccoon genetics, the genetic population structure of neutral mitochondrial DNA haplotypes are characterised in the expanding population, every 25 years, using a genetic distance measure, ϕ ST, Mantel tests and a gene diversity measure. The river barrier effect is assessed by comparing genetic measures computed from model outputs to those calculated from 166 raccoons recently sampled from the same landscape. The “best fit” between modelled scenarios and field data indicate the river prevents 50% of attempts to cross the river. Founder effects dominated the colonizing genetic population structure, and, as the river barrier effect increased, its genetic diversity decreased. Using gene flow to calibrate the effect of the river as a barrier to movement provides an estimate of the effect of a river in reducing the likelihood of cross-river infection. Including individual genetic markers in simulation modelling benefits investigations of disease spread and control. [Copyright &y& Elsevier]