Viral meningitis epidemics and a single, recent, recombinant and anthroponotic origin of swine vesicular disease virus.

BACKGROUND AND OBJECTIVES: Swine vesicular disease virus (SVDV) is a close relative of the human Enterovirus B serotype, coxsackievirus B5. As the etiological agent of a significant emergent veterinary disease, several studies have attempted to explain its origin. However, several key questions remain, including the full biological ancestry of the virus, and its geographical and temporal origin. METHODOLOGY: We sequenced near-complete genomes of 27 SVDV and 13 coxsackievirus B5 samples, all originally isolated between 1966 and 2006, and analysed these in conjunction with existing sequences and historical information. RESULTS: While analyses incorporating 24 additional near-complete SVDV genomic sequences indicate clear signs of within-SVDV recombination, all 51 SVDV isolates remain monophyletic. This supports a hypothesis of a single anthroponotic transfer origin. Analysis of individual coding and non-coding regions supports that SVDV has a recombinant origin between coxsackievirus B5 and another Enterovirus B serotype, most likely coxsackievirus A9. Extensive Bayesian sequence-based analysis of the time of the most recent common ancestor of all analysed sequences places this within a few years around 1961. Epidemiological evidence points to China as an origin, but there are no available samples to test this conclusively. CONCLUSIONS AND IMPLICATIONS: Historical investigation and the clinical aspects of the involved Enterovirus B serotypes, makes the current results consistent with a hypothesis stating that SVDV originated through co-infection, recombination, and a single anthroponotic event, during large viral meningitis epidemics around 1960/1961 involving the ancestral serotypes. The exact geographical origin of SVDV may remain untestable due to historical aspects.

Near-complete genome sequencing of swine vesicular disease virus using the Roche GS FLX sequencing platform.

Swine vesicular disease virus (SVDV) is an enterovirus that is both genetically and antigenically closely related to human coxsackievirus B5 within the Picornaviridae family. SVDV is the causative agent of a highly contagious (though rarely fatal) vesicular disease in pigs. We report a rapid method that is suitable for sequencing the complete protein-encoding sequences of SVDV isolates in which the RNA is relatively intact. The approach couples a single PCR amplification reaction, using only a single PCR primer set to amplify the near-complete SVDV genome, with deep-sequencing using a small fraction of the capacity of a Roche GS FLX sequencing platform. Sequences were initially verified through one of two criteria; either a match between a de novo assembly and a reference mapping, or a match between all of five different reference mappings performed against a fixed set of starting reference genomes with significant genetic distances within the same species of viruses. All reference mappings used an iterative method to avoid bias. Further verification was achieved through phylogenetic analysis against published SVDV genomes and additional Enterovirus B sequences. This approach allows high confidence in the obtained consensus sequences, as well as provides sufficiently high and evenly dispersed sequence coverage to allow future studies of intra-host variation.

Probable transmission of coxsackie B3 virus from human to chimpanzee, Denmark.

In 2010, a chimpanzee died at Copenhagen Zoo following an outbreak of respiratory disease among chimpanzees in the zoo. Identification of coxsackie B3 virus, a common human pathogen, as the causative agent, and its severe manifestation, raise questions about pathogenicity and transmissibility among humans and other primates.