Investigation of the presence of canine adenovirus (CAdV) in owned dogs in Northern Italy.

The use of a modified live canine adenovirus (CAdV) vaccine has greatly reduced the incidence of infectious canine hepatitis (ICH) in dogs. Nevertheless, cases of CAdV type 1 and 2 (CAdV-1 and CAdV-2) infection have been recently reported posing questions about the epidemiological situation of CAdV in dogs. In order to assess the presence of CAdV, samples from 51 dogs presented at a Veterinary Teaching Hospital in Bologna, Italy, for reasons unrelated with CAdV infection, were tested with a polymerase chain reaction (PCR) assay for CAdV. Thirty dogs (58.8%) were PCR positive for CAdV-2 infection and four of them (7.8%) were positive for CAdV-1. Sequence analysis performed on the obtained PCR products suggests that a genetically stable CAdV-1 strain and different CAdV-2 strains circulate in the canine population examined and that coinfections are relatively frequent.

Reversion to virulence of a subtype B avian metapneumovirus vaccine: is it time for regulators to require availability of vaccine progenitors?

Empirically derived live avian metapneumovirus (AMPV) vaccines developed during the late 80s and early 90s have generally performed well in controlling turkey rhinotracheitis. Nonetheless, unstable attenuation was previously demonstrated in an AMPV subtype A vaccine. Until now this had not been investigated in subtype B vaccines due to lack of any similar availability of a vaccine progenitor or its sequence. The publication of the full genome sequence for the VCO3 vaccine progenitor facilitated a conclusive investigation of two AMPVs isolated from poults on a farm which had been vaccinated with VCO3 derived vaccine. Full genome sequencing of the isolates and their comparison to sequences of the vaccine and its progenitor, confirmed their vaccine origin. After determining the absence of extraneous infectious agents, one of these virus isolates was inoculated into 1-day-old turkeys in disease secure isolators and shown to cause disease with a severity similar to that caused by virulent field virus. This suggests that instability in live AMPV vaccines may be generalized and highlights the need for availability of vaccine progenitor sequences for the field assessment of all live viral vaccines.

Antiviral activity of HPMPC (cidofovir) against orf virus infected lambs.

(S)-1-[3-hydroxy-2-(phosphonomethoxy)propyl]cytosine [corrected] (HPMPC, cidofovir, CDV, Vistide) is an acyclic nucleoside analogue with a potent and selective activity against a broad spectrum of DNA viruses including the poxviruses. In this study we present the results of different treatment regimens in lambs experimentally infected with orf virus with different cidofovir formulations prepared in Beeler basis and Unguentum M. Our results show that choice of excipient, concentration of codofovir [corrected] and treatment regimen were all important to the clinical outcome of the therapy. Whilst one particular regimen appeared to exacerbate the lesion, treatment with 1% (w/v) cidofovir cream, prepared in Beeler basis, for 4 consecutive days did result in milder lesions that resolved in milder lesions that resolved [corrected] more quickly than untreated lesions. Furthermore the scabs of the treated animals contained significantly lower amounts of viable virus meaning there should be less contamination of the environment with virus than would normally occur.

Temperature-dependency of Betanodavirus infection in SSN-1 cell line.

This study examined the in vitro effects of temperature on Betanodavirus infection in the SSN-1 cell line. A Betanodavirus isolated from moribund sea bass fry Dicentrarchus labrax farmed in the Adriatic Sea and characterised as a RGNNV (Redspotted Grouper Nervous Necrosis Virus) genotype was used. Virus-infected SSN-1 cells were incubated at temperatures between 10 and 30 degrees C and observed for cytopathic effects daily for 15 d. Cell-free and cell-associated viral growth were evaluated by 50% tissue culture infectious dose (TCID50) titration at 0, 24, 48, 72, 96, 144, 192, 240, 312 and 360 h post-infection. Virus replication was observed at all temperatures from 15 to 30 degrees C. The optimal temperature for virus growth was 25 degrees C. A temperature of 10 degrees C was detrimental to the growth of the SSN-1 cells and cell death interfered with interpretations of viral growth. The isolate of Betanodavirus from Italian sea bass in this study demonstrates a different temperature range for growth compared to previous reports for related Betanodavirus strains, most likely due to an adaptation to the normal environmental temperatures of the host fish species of origin.

Experimental infection of 3-week-old conventional colostrum-fed pigs with porcine circovirus type 2 and porcine parvovirus.

This report describes an experimental infection with porcine circovirus type 2 (PCV2) in combination with porcine parvovirus (PPV) in 3-week-old conventional colostrum-fed pigs with maternal antibodies to both viruses. Two groups of four pigs each were inoculated with PCV2 and PPV. One of the groups received also a commercial inactivated vaccine against porcine pleuropneumonia to evaluate possible effects of the stimulation of the immune system of pigs on the infection. Another group of four pigs was kept as uninfected control. Clinical signs, rectal temperatures and body weights were recorded. Serum antibody titers to PCV2 and PPV were determined at weekly intervals. Pigs were killed 42 days after inoculation and tissue samples were examined for the presence of gross and microscopic lesions. Tissues were also analyzed for the presence of PCV2 and PPV DNA by PCR, and for the presence of PCV2 antigen by immunohistochemistry (IHC). All the pigs had serum antibodies to PCV2 and PPV at the beginning of the trial. None of them developed clinical symptoms or pathological lesions typical of post-weaning multisystemic wasting syndrome (PMWS), a disease associated to PCV2 infection. However, IHC and/or PCR analyses showed that clinically silent PCV2 infection developed in five of the eight inoculated pigs, regardless of the administration of the vaccine. In particular, PCV2 DNA and/or antigen were detected in most of the tissues examined in the two pigs with the lowest titer of maternal PCV2 antibodies at the beginning of the trial. PPV DNA was not detected in any of the samples examined. The five pigs with PCR and/or IHC evidence of PCV2 infection had a mean weight gain during the experiment lower than that of the inoculated PCR-negative pigs considered together and that of the control pigs. In conclusion, it would appear that passive immunity against PCV2 can play a role in preventing the development of PMWS, but is not able to prevent the establishing of clinically silent PCV2 infections. The dissemination and persistence of the virus in the tissues may depend on the level of PCV2 antibodies at the time of inoculation.

Incidence of injuries caused by dogs and cats treated in emergency departments in a major Italian city.

OBJECTIVE: This study aimed to estimate the incidence and characteristics of injuries caused by dogs and cats in the population of a major Italian city. METHODS: The clinical records of all patients attending the emergency department (ED) were obtained from the two main hospitals of the city, covering an estimated population of over half a million. A case was defined as a patient admitted for bite or scratch injuries caused by dogs, cats, or other mammals between 1 January 2000 and 31 December 2002. For each case, the information collected included age and sex of the patient, the anatomical site of the injury, and the species of the animal involved. RESULTS: The average yearly incidence of dog and cat bite/scratches was 58.4 and 17.9 cases per 100 000 residents, respectively. Admissions peaked during the summer months. Dogs accounted for 76.9% and cats for 19.7% of cases. Dog injuries were significantly more common in males and younger individuals. Children younger than 9 years had a significantly higher risk of being bitten on the head, face, or neck. Conversely, injuries from cats were significantly more common in females and older people. CONCLUSIONS: Surveillance of injuries caused by dogs and cats could provide useful information for planning and evaluating public health interventions. Collection of data from hospital EDs may be an appropriate, simple, and quick tool for monitoring the phenomenon and evaluating the associated risk factors.

Heparin binding activity of orf virus F1L protein.

The orf virus is the type species of the Parapoxvirus genus and is the causative agent of contagious echtyma, a debilitating skin disease of sheep and goats, which can also affect man. The virus exhibits a restricted host range, even if it has been shown to bind to a wide range of tissues of non-permissive species. This ability is an argument for its potential use as an expression vector. Since most mammalian cell types express heparan sulfate (HS) surface receptors, we assumed that HS could serve as receptors to mediate orf virus binding. In this study, we showed that orf virus is inhibited by the addition of soluble heparin in cell cultures. Affinity chomatography using heparin agarose demonstrated that orf virus F1L is the major heparin binding protein. Furthermore, the recombinant F1L protein was visualised on the cell surface by confocal microscopy, and rabbits immunised with recombinant F1L protein produced virus neutralising antibodies. These results confirm that the F1L immunodominant protein is also involved in virus binding to cells as for the vaccinia homologue H3L protein. Heparin also inhibited the binding of the F1L protein to cells showing that this protein has a role in the early stages of infection.

Diagnosis of orf virus infection in humans by the polymerase chain reaction.

The orf virus is the causal agent of contagious ecthyma in goats and sheep. The infection can be transmitted to humans and represents a typical example of occupational zoonosis. In Italy, the incidence of human infection remains uncertain because the disease is rarely reported or diagnosed. In this paper, we report a case of human orf virus infection and the laboratory methods of diagnosis. We demonstrated a genomic identity between the conserved and the variable regions of the genome of the viral strains isolated from the human patient and from the infected sheep confirming that there is no specific clone infecting humans rather than animals.

Characterisation of immunodominant protein encoded by the F1L gene of orf virus strains isolated in Italy.

We analysed the molecular properties of the immunodominant protein of different orf virus strains isolated in Italy. The F1L encoding genes and the deduced amino acid sequences of all strains were determined and compared, and they showed several mutations. Structural analysis was carried out in order to assess the influence of amino acid variations on protein structure demonstrating a conservation of the secondary structure. Western blot analysis and immunogold electron microscopy showed that all orf virus strains were antigenically identical. The results of our study confirmed the immunogenicity of the F1L protein; furthermore, our data suggest a possible involvement of the protein in the virus cycle.

Reliability of results of the Rose Bengal test performed for export control in northern Somalia.

Sera from sheep and goats in northern Somalia which are exported to countries of the Persian Gulf are systematically checked for brucellosis by local veterinary teams. The standard test used is rapid seroagglutination using the Rose Bengal test (RBT) and seropositive animals are not exported. In order to assess the reliability of the serological results, three randomised batches of samples (653 sera), corresponding to an equivalent number of shipments (October and December 1994 and March 1995) were counterchecked. Control RBTs were carried out by expatriate veterinarians working on behalf of international non-governmental organisations and by the Istituto Zooprofilattico Sperimentale of Padua, Italy, which also performed the complement fixation test (CFT). A fourth batch (n = 100), including a group of sera found positive by the local veterinary teams, was also checked. Agreement ranged from 96.3% to 98.5%.

Detection of canine parvovirus in wolves from Italy.

One hundred fifteen samples of wolf (Canis lupus) feces were collected during 1994 to 1995 from four free-living populations of the north central Apennines Mountains, Italy. The samples were tested for canine parvovirus by antigen-capture enzyme-linked immunosorbent assay (ELISA), hemagglutination, and virus isolation. Four of these samples were positive by virus isolation as confirmed by electron microscopy. All positive samples were from Casentino Park in Tuscany. This is the first definitive observation of canine parvovirus in wolves from Europe.