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In July 2011, in a zoological garden in Rome, Italy, malignant catarrhal fever ( MCF), a fatal, systemic disease of Artiodactyla, was suspected on the basis of neurological signs and gross lesions observed in a banteng, the first animal to die of this infection. An MCF type-specific PCR with subsequent sequencing of the PCR amplicon confirmed the aetiological agent as ovine herpesvirus-2 (Ov HV-2). Biological samples were collected from the dead animals for gross, histological, bacteriological, virological and serological examinations. An epidemiological investigation was conducted to identify the source of the outbreak, as further deaths due to Ov HV-2 still occurred after the removal of the acknowledged reservoirs, domestic sheep and goats. For this purpose, samples from other susceptible species and reservoir hosts were collected for virological and serological analysis. In conjunction, a retrospective sero-investigation was conducted on sera collected between 1999 and 2010 from some of the species involved in the present episode. In total, 11 animals belonging to four different species (banteng, Himalayan tahr, Nile lechwe and sika deer) died between July 2011 and October 2012. The severe gross and histological lesions were consistent with the disease, namely haemorrhages and congestion of several organs as well as lymphoid cell infiltrates and vasculitis of varying severity. The virological tests confirmed that all animals had died of sheep-associated MCF. The investigation indicated that the Ov HV-2 infection could have been due to the arrival of sheep in the petting zoo, with cases commencing after first lambing and subsequent shedding of virus. This was also supported by the serological retrospective study that indicated limited previous MCF virus circulation. Further MCF cases that occurred even after the removal of the domestic sheep and goats were attributed to the mouflon. This episode confirms the importance of biosecurity measures in zoos, which house MCF susceptible species, especially those endangered. [ABSTRACT FROM AUTHOR]

Bovine herpesvirus 1 (BoHV-1) is widely spread in bovine, considered the only species involved in the transmission of the infection. Scarce information is available relatively to BoHV-1 infection in the buffaloes. To evaluate their susceptibility, a virulent BoHV-1 field strain, isolated from cattle, was inoculated into this species. The study also investigated the establishment of viral latency through clinical, virological and serological investigations. Latency was also studied by attempting viral reactivation using pharmacological induction. Six, 5-month old, male, buffaloes were intranasally inoculated with BoHV-1; one animal was kept as a negative control. During the post-infection (PI) and post-pharmacological induction (PPI) periods, the animals were clinically monitored daily and nasal and rectal swabs, serum, plasma and leucocytes were periodically collected. On day 206, the animals were culled for the collection of the trigeminal ganglia and tonsils. No clinical signs referable to BoHV-1 were observed during the experiment. Seroconversion was detected in all infected buffaloes within day 9 PI. A Real Time PCR, amplifying a highly conserved region of the glycoprotein B gene of the Alphaherpesvirinae, was used for molecular analyses. All infected buffaloes scored DNA positive at least once in nasal or rectal swabs, between day 3 and 14 PI. Virus isolation in permissive cell-lines was successful for a fraction of the PCR positive samples. All samples tested negative during PPI, even if viral DNA was detected in the trigeminal ganglia of three animals. No clinical and laboratory evidence of infection was observed for the negative control. Viral reactivation was not observed, even if its DNA was detected in a recognised site for BoHV-1 latency. Our results demonstrate that buffaloes are susceptible to BoHV-1, eliminating virus principally via the nasal route. In view of these results and of the seroepidemiological evidence of BoHV-1 infection in buffaloes, a risk analysis for the control of BoHV-1 in bovines should consider the potential role of the former species. [ABSTRACT FROM AUTHOR]

During local respiratory disease outbreaks, occurring in 2003 and 2004 in horse training stables within race-tracks in Rome, and on a stud horse farm in Bari in 2005, four strains of equine influenza (EI) virus were isolated. All outbreaks occurred in flu-vaccinated horses. Here, we are reporting the results of the genetic characterization of these isolates, together with that of another EI virus strain isolated in 1999 from a dead foal presenting pulmonary lesions. Alignment and phylogenetic analyses were carried out using the haemagglutinin amino acid sequences. The Rome and Bari isolates were identified as members of the American lineage, closely related to other recent strains isolated in America as well as in Europe, including the latest recommended American lineage vaccine prototype A/eq/SouthAfrica/4/2003. In contrast, the Italian 1999 isolate was clustered within the European lineage. In Italy, the most recent outbreaks of EI have been caused by the currently circulating American-like strains, even in vaccinated populations, confirming that vaccines should contain an updated representative strain of this lineage. Presently, companies are still in the process of registering updated vaccines but no product is yet available on the market.

Several seroconversions occurring in 2002 among sentinel cattle during the bluetongue-vaccination campaign in Lazio and Tuscany (central Italy) led to the suspicion of vaccine-virus circulation. Therefore in 2003, 17 seroconverting sentinel herds were investigated for the characteristics of the virus involved. From these farms, 91 unvaccinated animals and 57 Culicoides pools were tested for the presence of the bluetongue vaccine virus (serotype-2) or other strains. The presence of vaccine virus serotype-2 was confirmed by PCR followed by restriction analysis in the whole blood of 17 unvaccinated sentinel cattle and 12 pools of Culicoides imicola or C. obsoletus. Of the 17 herds, five were positive only for vaccine virus serotype-2, four were positive for other strains and two for both the vaccine and other strains; the remaining premises were virologicaly negative. The vaccine virus serotype-2 also was detected in areas not included in the vaccination campaign.

During the epidemic of bluetongue (BT) in Lazio and Tuscany between 2001 and 2003, the distribution pattern of Culicoides imicola did not always correspond either geographically or seasonally, with virus circulation. Culicoides obsoletus was observed to be abundant, ubiquitous and active throughout the year. The geographical and seasonal distribution of BT virus (BTV), C. imicola and C. obsoletus was compared. The territory of the two regions was divided into 30 cells each measuring 1 600 km(2). The presence of C. obsoletus was recorded in every cell, while C. imicola was detected in 18 of the 30 cells, but was absent in 6 of the 21 cells that indicated the presence of BTV. The occurrence of seroconversions appeared to be positively correlated with maximum C. obsoletus catches. Seroconversions were recorded throughout the year, even when C. imicola was not active, whereas C. obsoletus was detected during the entire period. The occurrence of BTV circulation in areas and periods where C. imicola was absent, and the abundant and constant presence of adult C. obsoletus in all the cells, suggest the active role of the latter species in BTV circulation in central Italy.

The European brown hare syndrome virus (EBHSV) and the rabbit haemorrhagic disease (RHDV) virus were inoculated in hares and rabbits to discover whether the homologous and heterologous host could be infected. The aims were to confirm the results of previous studies that showed the existence of antigenic differences between these two viruses, and also to define the role attributed to the hare in transmission to rabbits of a disease, EBHS, initially mistaken for RHD. During the trials, clinical symptoms and pathological lesions were noted, and virological and serological analysis were conducted, using specific tests set up for both diseases. The hares infected with EBHSV died of an acute form of EBHS, whereas the rabbits remained healthy. The low serological response in these rabbits towards the EBHSV did not protect them against RHDV. Similarly, hares inoculated with RHDV remained healthy and showed a low anti-RHDV antibody titre but died when challenged with EBHSV.

Between August 1988 and August 1991, 456 carcasses of captive or sylvatic hares from several areas of northern Italy, and 931 sera taken from adult hares in farms, in hunting and natural reserves and on importation were examined using virological (sandwich enzyme-linked immunosorbent assay [ELISA] and immuno-electron microscopy) and serological (competition ELISA) tests. The epidemiological data presented relate to the incidence of European brown hare syndrome (EBHS) in various provinces of northern Italy, the mortality caused by EBHS and the seasonal frequency of this disease. The endemic character of EBHS in Italy is proved by the large number of samples testing positive for EBHS virus (EBHSV) (47.6%) and by the results of the seroepidemiological survey, in which approximately 95% of samples tested positive for specific anti-EBHSV antibodies, showing varying titres according to the different environmental conditions.

The authors studied an outbreak of an acute form of European brown hare syndrome (EBHS) in captive hares. The farm involved had shown negative results in a previous serological test for EBHS conducted on approximately 8% of the animals. Hares which succumbed during the outbreak were submitted to an anatomo-pathological examination and the livers of these animals were collected for laboratory analysis. Examination by immunoelectron microscopy and enzyme-linked immunosorbent assay confirmed the diagnosis of EBHS virus (EBHSV). An initial serological survey conducted on the survivors twenty-two days after the outbreak demonstrated an immunological response against EBHSV. During the outbreak, data were collected on morbidity, mortality, incidence of the disease in various age groups, and also on the antigenic characteristics of the virus responsible for the outbreak.

Development of methods for the diagnosis of viral haemorrhagic disease and the European brown hare syndrome has proceeded at a steady pace over the last few years. The studies conducted by the authors demonstrate that, like VHDV, EBHSV is a calicivirus. The degree of correlation between the two viruses is a key question both for understanding their biology and interpreting the diagnostic results. A discussion of the similarities and differences between VHD and EBHS is followed by the presentation of the latest antigenic correlation results of the two viruses. Considering the absence of culture procedures to isolate either virus, the diagnostic methods discussed in this review are the haemagglutination (HA) test, immune electron microscopy (IEM) and enzyme-linked immunosorbent assay (ELISA) for virus detection, and the haemagglutination inhibition test (HI) and ELISA for antibody detection. The major obstacles, especially for the diagnosis of EBHS, are described; these are represented by morphological, structural and antigenic modifications due to proteolytic degradation. A differential diagnostic method for the two diseases, based on MAb ELISA, is presented. A final conclusion, drawn from the epidemiological analysis of the virological and serological data, is that EBHS and VHD should be considered as two distinct diseases, each caused by its own aetiological agent.