Inter-serotype reassortment among epizootic haemorrhagic disease viruses in the United States

First described in 1955 in New Jersey, epizootic haemorrhagic disease (EHD) causes a severe clinical disease in wild and domestic ruminants worldwide. Epizootic haemorrhagic disease outbreaks occur in deer populations each year from summer to late autumn. The etiological agent is EHD virus (EHDV) which is a double-stranded segmented icosahedral RNA virus. EHD virus utilizes point mutations and reassortment strategies to maintain viral fitness during infection. In 2018, EHDV serotype 2 was predominantly detected in deer in Illinois. Whole genome sequencing was conducted for two 2018 EHDV2 isolates (IL41747 and IL42218) and the sequence analyses indicated that IL42218 was a reassortant between different serotypes whereas IL41747 was a genetically stable strain. Our data suggest that multiple strains contribute to outbreaks each year.

Novel porcine reproductive and respiratory syndrome virus strains in the United States with deletions in untranslated regions

Porcine reproductive and respiratory syndrome (PRRS) still causes major problems for the swine industry worldwide. Here, we report the detection and genomic characterization of two novel PRRS virus (PRRSV) strains from the United States with deletions in untranslated regions (UTRs). The OH155-2015 strain has two single-nucleotide deletions in the 5' UTR, whereas the OH28372-2013 strain has a 13-nt deletion in the 3' UTR. In addition, OH155-2015 and OH28372-2013 have a unique deletion and mutations in the NSP2 and N gene, respectively. Our study highlights the importance of continued monitoring of PRRSV using whole-genome sequencing.

Diagnostics for Viral Pathogens in Veterinary Diagnostic Laboratories

Laboratory testing is one part of clinical diagnosis, and quick and reliable testing results provide important data to support treatment decision and develop control strategies. Clinical viral testing has been shifting from traditional virus isolation and electron microscopy to molecular polymerase chain reaction and point-of-care antigen tests. This shift in diagnostic methodology also means change from looking for infectious virions or viral particles to hunting viral antigens and genomes. With technological development, it is predicted that metagenomic sequencing will be commonly used in veterinary clinical diagnosis for unveiling the whole picture of microbes involved in diseases in the future.