Parvovirus infections have been well known for around 100 years in domestic carnivores. However, the use of molecular assays and metagenomic approaches for virus discovery and characterization has led to the detection of novel parvovirus species and/or variants in dog. Although some evidence suggests that these emerging canine parvoviruses may act as primary causative agents or as synergistic pathogens in the diseases of domestic carnivores, several aspects regarding epidemiology and virus-host interaction remain to be elucidated.

Alphaherpesviruses cause genital lesions and reproductive failure in both humans and animals. Their control is mainly based on prevention by hygienic prophylactic measures, due to the ab-sence of vaccines and limitations of antiviral drug therapy. Ozone is an oxidating gas showing a strong microbicidal activity on bacteria, fungi, viruses, and protozoa. The present study assessed the in vitro virucidal and antiviral activity of ozone against Caprine herpesvirus type 1. Virucidal activity of a gaseous mixture containing O3 at 20 and 50 μg /mL was assessed against the virus for different contact times (30 s, 60s, 90s, 120s, 180s and 300s). Antiviral activity of a gaseous mix-ture containing O3 at 20 and 50 μg /mL was evaluated against the virus to for 30s and 60s. Ozone displayed significant virucidal activity when used at all the tested concentrations whilst signifi-cant antiviral activity was observed using ozone at 50 μg/ml. The gaseous mixture, tested in the present study, showed virucidal and antiviral activity against CpHV-1 with a dose- and a time-contact -dependent fashion. Ozone therapy could be evaluated in vivo for the treatment of CpHV-1-induced genital lesions in goats, through topical applications.

Norovirus (NoV) is recognised as a major cause of epidemic and sporadic acute gastroenteritis (AGE) in all age groups. Information on the genetic diversity of the NoVs circulating in the 1980s and 1990s, before the development and adoption of dedicated molecular assays, is limited compared to the last decades. In the period 1986-2020, uninterrupted viral surveillance was conducted in symptomatic children hospitalized for AGE in Palermo, Italy, providing a unique time capsule for exploring the epidemiological and evolutionary dynamics of enteric viruses. In this 35-year long time span NoVs of genogroup II (GII) were detected in 15.6% of AGE requiring hospitalization, whilst GI NoVs in 1.4%. Overall, the predominant NoV capsid (Cap) genotype was GII.4 (60.8%), with temporal replacement of the GII.4 Cap variants and associated polymerase (Pol) types. The chronology of emergence and circulation of the different GII.4 variants were consistent with the data available in literature. Also, for GII.3 and GII.2 NoVs the circulation of different lineages/strains, differing in either the Cap or Pol genes or in both, was observed. This long-term study revealed the ability of NoVs to modify continuously and rapidly their genomic makeup and highlights the importance of surveillance activities for vaccine design.

Feline calicivirus (FCV) causes upper respiratory tract disease (URTD) and sporadic outbreaks of virulent systemic disease (FCV-VSD). The basis for the increased pathogenicity of FCV-VSD viruses is incompletely understood, and antivirals for FCV have yet to be developed. We investigated the clinicoepidemiology and viral features of three FCV-VSD outbreaks in Australia and evaluated the in vitro efficacy of nitazoxanide (NTZ), 2’-C-methylcytidine (2CMC) and NITD-008 against FCV-VSD viruses. Overall mortality among 23 cases of FCV-VSD was 39%. Metagenomic sequencing identified five genetically distinct FCV lineages within the three outbreaks, all seemingly evolving in situ in Australia. Notably, no mutations that clearly distinguished FCV-URTD from FCV-VSD phenotypes were identified. One FCV-URTD strain likely originated from a recombination event. Analysis of seven amino acid residues from the hypervariable E region of the capsid in the cultured viruses provided no support for the contention that properties of these residues can reliably differentiate between the two pathotypes. On plaque reduction assays, dose-response inhibition of FCV-VSD was obtained with all antivirals at low micromolar concentrations; NTZ EC50, 0.4-0.6 µM, TI 21; 2CMC EC50, 2.7-5.3 µM, TI >18; NITD-008, 0.5 to 0.9 µM, TI >111. Investigation of these antivirals for treatment of FCV-VSD is warranted.