Epidemiology, surveillance and diagnosis of Usutu virus infection in the EU/EEA, 2012 to 2021.

BackgroundUsutu virus (USUV) is a flavivirus with an enzootic cycle between birds and mosquitoes; humans are incidental dead-end hosts. In Europe, the virus was first detected in Italy in 1996; since then, it has spread to many European countries.AimWe aimed to report on the epidemiology, surveillance, diagnosis and prevention of USUV infection in humans, mosquitoes and other animals in the European Union/European Economic Area (EU/EEA) from 2012 to 2021.MethodsWe collected information through a literature review, an online survey and an expert meeting.ResultsEight countries reported USUV infection in humans (105 cases, including 12 [corrected] with neurological symptoms), 15 countries in birds and seven in mosquitoes. Infected animals were also found among pets, wild and zoo animals. Usutu virus was detected primarily in Culex pipiens but also in six other mosquito species. Detection of USUV infection in humans is notifiable only in Italy, where it is under surveillance since 2017 and now integrated with surveillance in animals in a One Health approach. Several countries include USUV infection in the differential diagnosis of viral encephalitis and arbovirus infections. Animal USUV infection is not notifiable in any EU/EEA country.ConclusionHuman USUV infections, mainly asymptomatic and, less frequently, with a febrile illness or a neuroinvasive disease, have been reported in several EU/EEA countries, where the virus is endemic. Climate and environmental changes are expected to affect the epidemiology of USUV. A One Health approach could improve the monitoring of its evolution in Europe.

Detection and whole genome sequencing of murine norovirus in animal facility in Italy.

Viruses belonging to the genus Norovirus (NoV) of the family Caliciviridae are the major cause of acute viral gastroenteritis worldwide. NoVs are classified into 10 genogroups (GI-GX), and those belonging to the genogroup GV are able to infect several species of rodents. To evaluate the circulation of MNV among mice housed in an Italian facility, sampling was performed over two separate periods, in 2011, and 3 years later in 2014. During the two samplings, 75 fecal samples were collected from healthy mice housed in the animal facility and subjected to RT-PCR for viral detection. After the analysis, 41/75 animals (54.6%) resulted positive for the presence of MNV in feces. Nucleotide sequencing revealed the presence of two MNV variants co-circulating in both 2011 and 2014. One MNV strain was isolated on RAW264.7 cell line, and subjected to full genome sequencing. Our study showed that the murine noroviruses are widespread in the investigated animal facility, despite guidelines for animal care and maintenance. Full genome sequence analysis of the MNV strain described in this study showed a correlation with other strains circulating in Europe. Understanding the molecular epidemiology of this virus should give insight into its natural history and evolution in mice.

Infection of farmed pigs with porcine kobuviruses in Italy.

Two-hundred eight swine fecal samples from six Italian farms were tested using a kobuvirus-specific RT-PCR with primers that amplify a region within the 3D gene. All farms were kobuvirus positive, with prevalence rates ranging between 24 % and 84 %. Overall, 57.5 % of asymptomatic pigs and 49.7 % of animals with diarrhea were positive for kobuvirus. Sequence analysis showed a different predominant strain circulating on each farm and indicated that the strains detected were related to both European and Asiatic strains. A possible pathogenic role of kobuvirus should be investigated further, since infections with this virus occur frequently in pigs of different ages.

Detection and molecular characterization of zoonotic viruses in swine fecal samples in Italian pig herds.

Gastrointestinal disease is frequent in pigs, and among the different etiological agents involved, viruses are considered the leading cause of infection in this animal species. Furthermore, about half of the newly identified swine pathogens are viruses, many of which may be transmitted to humans by direct contact or by indirect transmission pathways. In this study, the prevalence of astrovirus (AstV), group A rotavirus (RVA), norovirus (NoV) and hepatitis E virus (HEV) infections in pigs was investigated. During 2012-2014, 242 fecal samples were collected from pigs at different production stages (5 to 220 days old) on eight swine farms located in northern, central and southern Italy. Seven out of eight farms analyzed were positive for AstV, which was detected in 163 out of 242 (67.4%) samples and was the most prevalent virus; 61 of the 163 AstV-positive animals (37.4%) had diarrhea. HEV was detected on six farms and in 45 (18.6%) of the 242 samples analyzed. Twenty-three HEV-infected pigs had diarrhea (51.1%). A lower prevalence was observed for RVA, which was found in 10 of the 242 samples (4.1%) from three positive farms, and diarrhea was present only in six infected pigs (60.0%). No swine samples were found to be positive for NoV. Genetic diversity and phylogenetic relationships of some strains representative of the different viruses detected were investigated, confirming a wide heterogeneity of viral strains circulating among pigs.

Detection and characterization of porcine caliciviruses in Italy.

Porcine noroviruses and sapoviruses have been sporadically reported in European countries, and more rarely in Italy. In this study, stools samples were collected from both asymptomatic and diarrheic pigs from northern Italy and were screened for caliciviruses by RT-PCR. Sapoviruses were detected frequently and were genetically related to both the GIII reference strain and the newly described porcine sapovirus genogroups. Porcine norovirus was detected in one asymptomatic pig (0.5%) and was genotyped as GII.11. This is the first detection of porcine norovirus in Italy.

Zoonotic transmission of hepatitis E virus in industrialized countries.

Hepatitis E is an infectious viral disease with clinical and morphological features of acute hepatitis. The disease represents an important public health problem in developing countries, where it is often related to outbreaks mainly associated with consumption of contaminated water. During recent years, an increasing number of sporadic cases have also been described in industrialized countries. Besides humans, the hepatitis E virus (HEV) has also been identified in animals. In 1997, the virus was first detected in swine, and is now considered ubiquitous. Human and swine HEV strains from the same geographical region present a high level of nucleotide identity, and experimental infections have confirmed the cross-species transmission of swine strains to humans and of human strains to non-human primates. Studies on anti-HEV antibodies detection have demonstrated that people working in contact with swine or wild boar have a higher risk of infection than normal blood donors. In Japan and more recently in France, cases of hepatitis E have been associated with ingestion of uncooked meat from pigs, wild boar, or deer. The disease is currently considered an emerging zoonosis.

The Occurrence of Freshwater Fish-Borne Zoonotic Helminths in Italy and Neighbouring Countries: A Systematic Review.

In recent years, the consumption of fish products has surged in European countries, being an essential part of a healthy diet. Despite representing a small part of EU production, freshwater fisheries hold considerable significance for lake-dwelling populations and tourists seeking traditional dishes. This increased fish consumption has brought to light potential health risks associated with fish-borne zoonotic helminths (FBZHs), now acknowledged as global food-borne parasites. Fish-borne zoonotic helminths belong to various taxonomic groups, including nematodes (Anisakidae), trematodes (Opisthorchiidae and Heterophyidae), and cestodes (Diphyllobothriidae). More than 50 species of FBZH are known to cause human infections, derived from eating raw or undercooked aquatic foods containing viable parasites. Despite increased attention, FBZHs remain relatively neglected compared to other food-borne pathogens due to factors like chronic disease progression and under-diagnosis. This systematic review concentrates on the prevalence of six freshwater FBZHs (Clinostomum complanatum, Contracaecum rudolphii, Dibothriocephalus latus, Eustrongylides excisus, Opisthorchis felineus, and Pseudamphistomum truncatum) in Italy and neighbouring countries. The study explores the expansion of these parasites, analysing their biological and epidemiological aspects, and the factors that influence their proliferation, such as the increased cormorant population and the lake eutrophication phenomena. In summary, this research highlights the necessity for further research, the development of spatial databases, and the establishment of a unified European policy to effectively manage these multifaceted health concerns. It strongly advocates adopting a One-Health approach to address the growing incidence of parasitic zoonoses within the context of food safety in EU countries.

Hepatitis E virus in pork production chain in Czech Republic, Italy, and Spain, 2010.

We evaluated the prevalence of hepatitis E virus (HEV) in the pork production chain in Czech Republic, Italy, and Spain during 2010. A total of 337 fecal, liver, and meat samples from animals at slaughterhouses were tested for HEV by real-time quantitative PCR. Overall, HEV was higher in Italy (53%) and Spain (39%) than in Czech Republic (7.5%). HEV was detected most frequently in feces in Italy (41%) and Spain (39%) and in liver (5%) and meat (2.5%) in Czech Republic. Of 313 sausages sampled at processing and point of sale, HEV was detected only in Spain (6%). HEV sequencing confirmed only g3 HEV strains. Indicator virus (porcine adenovirus) was ubiquitous in fecal samples and absent in liver samples and was detected in 1 slaughterhouse meat sample. At point of sale, we found porcine adenovirus in sausages (1%-2%). The possible dissemination of HEV and other fecal viruses through pork production demands containment measures.

Systemic Bovine Tuberculosis in a Crested Porcupine (Hystrix cristata) in the Marche Region, Italy.

Tuberculosis is a worldwide zoonosis involving a wide range of hosts among domestic and wild animals. We describe tuberculosis caused by Mycobacterium bovis in a wild crested porcupine (Hystrix cristata) found dead in the district of Macerata, Marche Region, Italy in 2019.

Complete genome sequencing of a genotype 3 hepatitis E virus strain identified in a swine farm in Italy.

In this study, we investigated hepatitis E virus (HEV) infection in piglets sampled in two farms in southern Italy. The virus was detected in 11 out of 15 animals tested. Based on sequence analysis, the 6 Italian strains examined belonged to two clusters containing both swine and human strains of either genotype 3 subtype e or f from Europe and Japan. The two Italian strain clusters shared nucleotide identity of 81.8% and 87.5% in the ORF2 (capsid protein) and ORF1 (RdRp) diagnostic fragments, respectively, confirming the heterogeneity of genotype 3 viruses circulating in pigs in Italy. The complete genome of one genotype 3 subtype e strain and the full ORF2 and ORF3 coding regions of one of the genotype 3f strains, obtained in this study, were compared to other HEV sequences available on line (NCBI database). The results of analysis showed that porcine strains clustered together with human and swine strains detected in Europe. Most changes in the coding region corresponded to synonymous mutations, and only the ORF3 showed a positive selection. Further, analyses are needed to understand the clinical significance of HEV genotypes and subtypes.

Detection of hepatitis E virus in pork liver sausages.

Hepatitis E infection is regarded as an emerging public-health concern. The disease is normally self-limiting (mortality rate 1%), but chronic infections have recently been observed in transplanted patients. The etiological agent HEV is a small RNA virus infecting both humans and animals. In humans, the disease may be food-borne and pig is a main reservoir for zoonotic strains. In the present study, we evaluated the presence of HEV and swine fecal cross-contamination in pork liver sausages sold at a grocery store in Italy. HEV genome detection was performed by RT-qPCR, using harmonized protocols that included a process control (murine norovirus) and an internal amplification control. Swine fecal cross-contamination was assessed by determination of the ubiquitous porcine adenovirus. Overall, HEV genome belonging to genotype 3 was detected in both raw (10 out of 45 slices, 250 mg each, 22.2%) and dry (1 of 23 slices, 4.3%) liver sausages, but infectivity of the virus was not demonstrated. This pilot study fosters more investigations on HEV presence in pork-derived food, to assess the possible risk for the consumers.

Control of a Reassortant Pandemic 2009 H1N1 Influenza Virus Outbreak in an Intensive Swine Breeding Farm: Effect of Vaccination and Enhanced Farm Management Practices.

Influenza A viruses in swine cause considerable economic losses and raise concerns about their zoonotic potential. The current paucity of thorough empirical assessments of influenza A virus infection levels in swine herds under different control interventions hinders our understanding of their effectiveness. Between 2012 and 2013, recurrent outbreaks of respiratory disease caused by a reassortant pandemic 2009 H1N1 (H1N1pdm) virus were registered in a swine breeding farm in North-East Italy, providing the opportunity to assess an outbreak response plan based on vaccination and enhanced farm management. All sows/gilts were vaccinated with a H1N1pdm-specific vaccine, biosecurity was enhanced, weaning cycles were lengthened, and cross-fostering of piglets was banned. All tested piglets had maternally-derived antibodies at 30 days of age and were detectable in 5.3% of ~90 day-old piglets. There was a significant reduction in H1N1pdm RT-PCR detections after the intervention. Although our study could not fully determine the extent to which the observed trends in seropositivity or RT-PCR positivity among piglets were due to the intervention or to the natural course of the disease in the herd, we provided suggestive evidence that the applied measures were useful in controlling the outbreak, even without an all-in/all-out system, while keeping farm productivity at full.

Prevalence and transmission of hepatitis E virus in domestic swine populations in different European countries.

BACKGROUND: Hepatitis E virus (HEV) genotype 3 and 4 can cause liver disease in human and has its main reservoir in pigs. HEV investigations in pigs worldwide have been performed but there is still a lack of information on the infection dynamics in pig populations. FINDINGS: The HEV transmission dynamics in commercial pig farms in six different European countries was studied. The data collected show prevalence in weaners ranging from 8% to 30%. The average HEV prevalence in growers was between 20% and 44%. The fatteners prevalence ranged between 8% and 73%. Sows prevalence was similar in all countries. Boar faeces were tested for HEV only in Spain and Czech Republic, and the prevalence was 4.3% and 3.5% respectively. The collected data sets were analyzed using a recently developed model to estimate the transmission dynamics of HEV in the different countries confirming that HEV is endemic in pig farms. CONCLUSIONS: This study has been performed using similar detection methods (real time RT-PCR) for all samples and the same model (SIR model) to analyse the data. Furthermore, it describes HEV prevalence and within-herd transmission dynamics in European Countries (EU): Czech Republic, Italy, Portugal, Spain, The Netherlands and United Kingdom, confirming that HEV is circulating in pig farms from weaners to fatteners and that the reproductive number mathematical defined as R0 is in the same range for all countries studied.