Tick-Borne Encephalitis, Lombardy, Italy.

Tick-borne encephalitis was limited to northeast portions of Italy. We report in Lombardy, a populous region in the northwest, a chamois displaying clinical signs of tickborne encephalitis virus that had multiple virus-positive ticks attached, as well as a symptomatic man. Further, we show serologic evidence of viral circulation in the area.

Isolation of Batborne Neglected Zoonotic Agent Issyk-Kul Virus, Italy.

We isolated Issyk-Kul virus (ISKV) from a bat sampled from Italy in 2021 and conducted ISKV-specific surveillance in bats collected in Italy during 2017-2023. ISKV circulation among synanthropic and sedentary species of bat, such as Savi's pipistrelle bat (Hypsugo savii) in northern Italy, may have public health implications in this region.

One health surveillance strategy for coronaviruses in Italian wildlife.

The recent reinforcement of CoV surveillance in animals fuelled by the COVID-19 pandemic provided increasing evidence that mammals other than bats might hide further diversity and play critical roles in human infectious diseases. This work describes the results of a two-year survey carried out in Italy with the double objective of uncovering CoV diversity associated with wildlife and of excluding the establishment of a reservoir for SARS-CoV-2 in particularly susceptible or exposed species. The survey targeted hosts from five different orders and was harmonised across the country in terms of sample size, target tissues, and molecular test. Results showed the circulation of 8 CoV species in 13 hosts out of the 42 screened. Coronaviruses were either typical of the host species/genus or normally associated with their domestic counterpart. Two novel viruses likely belonging to a novel CoV genus were found in mustelids. All samples were negative for SARS-CoV-2, with minimum detectable prevalence ranging between 0.49% and 4.78% in the 13 species reaching our threshold sample size of 59 individuals. Considering that within-species transmission in white-tailed deer resulted in raising the prevalence from 5% to 81% within a few months, this result would exclude a sustained cycle after spillback in the tested species.

Main causes of death of free-ranging bats in Turin province (North-Western Italy): gross and histological findings and emergent virus surveillance.

BACKGROUND: Bats are recognized as reservoir species for multiple viruses. However, little is known on bats' health and mortality. Thus, this study aimed to investigate the main causes of death of bats from Turin province (North-western Italy) and to describe gross and histopathological lesions potentially associated with the presence of selected bat viruses. RESULTS: A total of 71 bats belonging to 9 different species of the families Vespertilionidae and Molossidae were necropsied and samples of the main organs were submitted to histopathological examination. Also, aliquots of the small intestine, liver, spleen, lung, and brain were collected and submitted to biomolecular investigation for the identification of Coronaviridae, Poxviridae, Reoviridae (Mammalian orthoreovirus species), Rhabdoviridae (Vaprio ledantevirus and Lyssavirus species) and Kobuvirus. The majority of bats died from traumatic lesions due to unknown trauma or predation (n = 40/71, 56.3%), followed by emaciation (n = 13/71,18.3%). The main observed gross lesions were patagium and skin lesions (n = 23/71, 32.4%), forelimbs fractures (n = 15/71, 21.1%) and gastric distension (n = 10/71,14.1%). Histologically, the main lesions consisted of lymphoplasmacytic pneumonia (n = 24/71, 33.8%), skin/patagium dermatitis (n = 23/71, 32.4%), liver steatosis and hepatitis (n = 12, 16.9%), and white pulp depletion in the spleen (n = 7/71, 9.8%). Regarding emergent bat viruses, only poxvirus (n = 2, 2.8%) and orthoreovirus (n = 12/71, 16.9%) were detected in a low percentage of bats. CONCLUSIONS: Trauma is the main lesion observed in bats collected in Turin province (North-western Italy) associated with forelimb fractures and the detected viral positivity rate seems to suggest that they did not represent a threat for human health.

Asymptomatic infection with clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) in carnivore pets, Italy, April 2023.

In April 2023, an outbreak of clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses carrying the T271A mammalian adaptive mutation in the PB2 protein was detected in a backyard poultry farm in Italy. Five domestic dogs and one cat living on the premises had seroconverted in the absence of clinical signs. Virological and serological monitoring of individuals exposed to the virus proved the absence of human transmission, however, asymptomatic influenza A(H5N1) infections in mammalian pets may have important public health implications.

Preliminary results on an autochthonous dengue outbreak in Lombardy Region, Italy, August 2023.

In August 2023, six locally acquired dengue virus 1 infections were detected in Lodi province, Lombardy Region, in northern Italy, where the vector Aedes albopictus is present. Four cases were hospitalised, none died. The viruses clustered with Peruvian and Brazilian strains collected between 2021 and 2023. This preliminary report highlights the importance of continued integrated surveillance of imported vector-borne virus infections and the potential for tropical disease outbreaks in highly populated regions of northern Italy where competent vectors are present.

Characterization of the bioaerosol in a natural thermal cave and assessment of the risk of transmission of SARS-CoV-2 virus.

Thermal caves represent an environment characterized by unique chemical/physical properties, often used for treatment and care of musculoskeletal, respiratory, and skin diseases.However, these environments are poorly characterized for their physical and microbiological characteristics; furthermore, the recent pandemic caused by COVID-19 has highlighted the need to investigate the potential transmission scenario of SARS-CoV-2 virus in indoor environments where an in-depth analysis of the aerosol concentrations and dimensional distributions are essential to monitor the spread of the virus.This research work was carried out inside a natural cave located in Viterbo (Terme dei Papi, Italy) where a waterfall of sulfur-sulfate-bicarbonate-alkaline earth mineral thermal water creates a warm-humid environment with 100% humidity and 48 °C temperature. Characterization of the aerosol and bioaerosol was carried out to estimate the personal exposure to aerosol concentrations, as well as particle size distributions, and to give an indication of the native microbial load.The data obtained showed a predominance of particles with a diameter greater than 8 µm, associated with low ability of penetration in the human respiratory system. A low microbial load was also observed, with a prevalence of noncultivable strains generated by the aerosolization of the thermal waters.Finally, the estimation of SARS-CoV-2 infection risk by means of mathematical modeling revealed a low risk of transmission, with a decisive effect given by the mechanical ventilation system, which together with the adoption of social distancing measures makes the risk of infection extremely low.

Genome sequence of an aichivirus detected in a common pipistrelle bat (Pipistrellus pipistrellus).

The family Picornaviridae includes important human and animal pathogens that are associated with a wide range of diseases and, in some cases, have zoonotic potential. During epidemiological surveillance of bats, we identified, by next-generation sequencing (NGS) techniques, the presence of picornavirus RNA in a common pipistrelle bat (Pipistrellus pipistrellus). By coupling NGS, primer-walking strategies, and sequence-independent protocols to obtain the sequences of the 5' and 3' termini, we reconstructed the genome sequence of picornavirus strain ITA/2017/189/18-155. The genome of the bat picornavirus is 8.2 kb in length and encodes a polyprotein of 2462 amino acids. A comparison of polyprotein sequences revealed that this virus is distantly related (65.1% and 70.9% sequence identity at the nucleotide and amino acid level, respectively) to a bat aichivirus identified in 2010. Phylogenetic analysis showed that this picornavirus clustered closely with members of the genus Kobuvirus, which also includes human and animal aichiviruses. The identification of aichiviruses in several animal hosts is providing hints that will lead to an understanding of their origin and evolutionary patterns.

Taxonomy of the order Mononegavirales: update 2019.

In February 2019, following the annual taxon ratification vote, the order Mononegavirales was amended by the addition of four new subfamilies and 12 new genera and the creation of 28 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).

Isolation of a novel Rhabdovirus from an insectivorous bat (Pipistrellus kuhlii) in Italy.

BACKGROUND: Rhabdoviridae is one of the most ecologically diverse families of RNA viruses which can infect a wide range of vertebrates and invertebrates. Bats, among mammals, are pointed to harbor a significantly higher proportion of unknown or emerging viruses with zoonotic potential. Herein, we report the isolation of a novel rhabdovirus, detected in the framework of a virological survey on bats implemented in North Italy. METHODS: Virus isolation and identification were performed on samples of 635 bats by using cell cultures, negative staining electron microscopy and PCRs for different viruses. NGS was commonly performed on cell culture supernatants showing cytopathic effect or in case of samples resulted positive by at least one of the PCRs included in the diagnostic protocol. RESULTS: A rhabdovirus was isolated from different organs of a Pipistrellus kuhlii. Virus identification was obtained by electron microscopy and NGS sequencing. The complete genome size was 11,774 nt comprised 5 genes, encoding the canonical rhabdovirus structural proteins, and an additional transcriptional unit (U1) encoding a hypothetical small protein (157aa) (3'-N-P-M-G-U1-L-5'). The genome organization and phylogenetic analysis suggest that the new virus, named Vaprio virus (VAPV), belongs to the recently established genus Ledantevirus (subgroup B) and it is highly divergent to its closest known relative, Le Dantec virus (LDV) (human, 1965 Senegal). A specific RT-PCR amplifying a 350 bp fragment of the ORF 6 gene, encoding for L protein, was developed and used to test retrospectively a subset of 76 bats coming from the same area and period, revealing two more VAPV positive bats. CONCLUSIONS: VAPV is a novel isolate of chiropteran rhabdovirus. Genome organization and phylogenetic analyses demonstrated that VAPV should be considered a novel species within the genus Ledantevirus for which viral ecology and disease associations should be investigated.

Correction to: Detection and full genome characterization of two beta CoV viruses related to Middle East respiratory syndrome from bats in Italy.

CORRECTION: After Publication of the article [1], it has been brought to our attention that an author's name has been spelt incorrectly. The correct spelling should be "Massimo Ciccozzi", but it was previously included as "Massimo Cicozzi". The original version has now been revised to reflect this.

Group A Rotavirus Associated with Encephalitis in Red Fox.

In 2011, a group A rotavirus was isolated from the brain of a fox with encephalitis and neurologic signs, detected by rabies surveillance in Italy. Intracerebral inoculation of fox brain homogenates into mice was fatal. Genome sequencing revealed a heterologous rotavirus of avian origin, which could provide a model for investigating rotavirus neurovirulence.

Detection and full genome characterization of two beta CoV viruses related to Middle East respiratory syndrome from bats in Italy.

BACKGROUND: Middle East respiratory syndrome coronavirus (MERS-CoV), which belongs to beta group of coronavirus, can infect multiple host species and causes severe diseases in humans. Multiple surveillance and phylogenetic studies suggest a bat origin. In this study, we describe the detection and full genome characterization of two CoVs closely related to MERS-CoV from two Italian bats, Pipistrellus kuhlii and Hypsugo savii. METHODS: Pool of viscera were tested by a pan-coronavirus RT-PCR. Virus isolation was attempted by inoculation in different cell lines. Full genome sequencing was performed using the Ion Torrent platform and phylogenetic trees were performed using IQtree software. Similarity plots of CoV clade c genomes were generated by using SSE v1.2. The three dimensional macromolecular structure (3DMMS) of the receptor binding domain (RBD) in the S protein was predicted by sequence-homology method using the protein data bank (PDB). RESULTS: Both samples resulted positive to the pan-coronavirus RT-PCR (IT-batCoVs) and their genome organization showed identical pattern of MERS CoV. Phylogenetic analysis showed a monophyletic group placed in the Beta2c clade formed by MERS-CoV sequences originating from humans and camels and bat-related sequences from Africa, Italy and China. The comparison of the secondary and 3DMMS of the RBD of IT-batCoVs with MERS, HKU4 and HKU5 bat sequences showed two aa deletions located in a region corresponding to the external subdomain of MERS-RBD in IT-batCoV and HKU5 RBDs. CONCLUSIONS: This study reported two beta CoVs closely related to MERS that were obtained from two bats belonging to two commonly recorded species in Italy (P. kuhlii and H. savii). The analysis of the RBD showed similar structure in IT-batCoVs and HKU5 respect to HKU4 sequences. Since the RBD domain of HKU4 but not HKU5 can bind to the human DPP4 receptor for MERS-CoV, it is possible to suggest also for IT-batCoVs the absence of DPP4-binding potential. More surveillance studies are needed to better investigate the potential intermediate hosts that may play a role in the interspecies transmission of known and currently unknown coronaviruses with particular attention to the S protein and the receptor specificity and binding affinity.

First identification of mammalian orthoreovirus type 3 in diarrheic pigs in Europe.

Mammalian Orthoreoviruses 3 (MRV3) have been described in diarrheic pigs from USA and Asia. We firstly detected MRV3 in Europe (Italy) in piglets showing severe diarrhea associated with Porcine Epidemic Diarrhea. The virus was phylogenetically related to European reoviruses of human and bat origin and to US and Chinese pig MRV3.

Pig Acute Phase Proteins as Non-Antibody Systemic Biomarkers of Intracellular Infections.

As an alternative to traditional serological markers, that is, antibodies, for serum-based specific diagnosis of infections, circulating non-antibody markers may be used to monitor active disease. Acute phase proteins (APPs) are a prominent class of such markers widely used for diagnosing ongoing inflammation and infection. In this chapter, basic theoretical and practical considerations on developing APP assays and using APPs as markers of ongoing infection are presented with a specific focus on intracellular infections in pigs. Examples on APP-based monitoring of infection in pigs with viruses such as porcine respiratory and reproductive syndrome virus (PRRSV), porcine endemic diarrhea virus (PEDV), and influenza A virus (IAV), as well as intracellular bacteria (Lawsonia intracellularis) and the protozoan intracellular parasites Toxoplasma gondii and Cryptosporidium parvum are presented, with an emphasis on major pig APPs C-reactive protein (CRP), haptoglobin, serum amyloid A (SAA), and pig major acute phase protein (pig-MAP). The performance of these APPs as biomarkers in a range of experimental infection studies in pigs is described as examples on their use for estimating the severity of infection, vaccine efficacy, herd health characterization, and differential diagnosis.

Identification of asinine gamma herpesviruses in a donkey with interstitial pulmonary fibrosis, pleural effusion and thrombocytopenia.

A 23-year-old domestic donkey (Equus asinus) referred for severe respiratory distress due to suspected equine asthma. Ultrasound of the chest revealed bilateral irregular pulmonary consolidation and pleural effusion. Airway endoscopy and tracheal wash cytology showed severe neutrophilic inflammation and bacterial culture was positive for Streptococcus equi subsp. zooepidemicus. Despite aggressive treatment, the donkey died in 48 hours. On post-mortem examination, the lung was whitish, collapsed, and firm, with fibrotic multifocal nodular areas. Pleural effusion and pleuritis were detected. Histologically, the lung architecture was markedly replaced by interstitial fibrosis. The histological features observed were suggestive of a severe chronic fibrosing interstitial pleuropneumonia with type 2 pneumocyte hyperplasia and intralesional syncytial cells. Pulmonary fibrosis was associated with the presence of asinine gammaherpesvirus 2 and 5 infection, confirmed by PCR and sequence analysis. The macroscopic and histological pattern of fibrosis was diffuse and interstitial, and the nodular lesions were consistent with spared lung parenchyma, instead of the canonical nodular distribution of the fibrosis observed in equine multinodular pulmonary fibrosis. Asinine herpesviral pulmonary fibrosis is uncommon, but should be considered by clinicians in the list of differentials in donkeys with chronic respiratory signs.

Characterization of environmental drivers influencing the abundance of Anopheles maculipennis complex in Northern Italy.

BACKGROUND: In Italy, malaria was endemic until the 1970s, when it was declared eradicated by WHO. Nowadays, with the persistence of competent mosquito populations, the effect of climate change, and increased possibility of importing malaria parasites from endemic counties due to growing migration, a malaria resurgence in Italy has become more likely. Hence, enhancing the understanding of the current distribution of the Anopheles maculipennis complex and the factors that influence the presence of this malaria vector is crucial, especially in Northern Italy, characterised by a high density of both human population and livestock. METHODS: To assess the presence and abundance of malaria vectors, a 4-year field survey in the plain areas of Lombardy and Emilia-Romagna region in Italy was conducted. Every sampling point was characterised in space by the land use in a 500-m radius and in time considering meteorological data collected in the short and long time periods before sampling. We combined the results of a linear regression model with a random forest analysis to understand the relative importance of the investigated niche dimensions in determining Anopheles mosquito presence and abundance. RESULTS: The estimated normalised variable importance indicates that rice fields were the most important land use class explaining the presence of Anopheles, followed by transitional woodlands and shrubland. Farm buildings were the third variable in terms of importance, likely because of the presence of animal shelters, followed by urbanised land. The two most important meteorological variables influencing the abundance of Anopheles in our study area were mean temperature in the 24 h before the sampling date and the sum of degree-days with temperature between 18 °C and 30 °C in the 14 days before the sampling date. CONCLUSIONS: The results obtained in this study could be helpful in predicting the risk of autochthonous malaria transmission, based on local information on land cover classes that might facilitate the presence of malaria vectors and presence of short- and medium-term meteorological conditions favourable to mosquito development and activity. The results can support the design of vector control measures through environmental management.

Development of two competitive ELISAs based on monoclonal antibodies for the serological detection of Bovine ephemeral fever virus.

Bovine ephemeral fever virus (BEFV) is a member of the genus Ephemerovirus in the family Rhabdoviridae. It is an arthropod-borne virus transmitted by many species of midges and mosquitoes. It can cause severe economic consequences due to losses in milk production and the general condition of cattle and water buffalo. BEF occurs in some tropical, subtropical and warm temperate regions of Africa, Australia, the Middle East and Asia with seasonal outbreaks, but its possible spread to other areas (e.g. Europe) cannot be excluded. Therefore, using and developing rapid diagnostic methods with optimal performance is essential for identifying emerging pathogens and their control. In the present study, we developed two competitive serological ELISAs based on monoclonal antibodies (mAbs), designed by using BEFV inactivated antigen and the BEF recombinant nucleoprotein (N), respectively. A panel of 77 BEF-positive and 338 BEF-negative sera was used to evaluate the two tests. With a diagnostic sensitivity of 97.4 % using the inactivated virus and 98.7 % using the recombinant N, and a diagnostic specificity of 100 % using both antigens, our results suggest that these tests are suitable for the serological diagnosis of BEF.

Strategic Challenges to the Eradication of African Swine Fever Genotype II in Domestic Pigs in North Italy.

African swine fever (ASF) is a severe viral disease characterized by high lethality in suids and caused by the African Swine Fever Virus (ASFV). The ASF genotype I virus was introduced to Europe in 1957, marking the onset of the first European epidemic wave. In 2007, ASFV genotype II was detected in Georgia, affecting domestic pigs and wild boars before spreading to various European and extra-European countries, including Italy. The first case of ASFV in Italy was documented on 7 January 2022, in a wild boar in the Piedmont region. Since then, several ASFV-positive wild boar carcasses have been identified in the Piedmont and Liguria regions. By June 2023, ASFV had spread to Lombardy, one of the major pig-producing regions in northern Italy; the virus was first detected in early summer in wild boar carcasses. Two months later, it was diagnosed in a commercial pig farm as a consequence of the disease's spread amongst wild boars and an increase in the viral environmental load. This report aims to describe the features of ASFV domestic pig outbreaks that occurred in the Zinasco municipality (Lombardy) and the joint efforts to mitigate potential direct and indirect economic impacts on the Italian and global pig industry. The epidemiological investigation and the measures implemented, which were all performed according to national and European regulations, as well as exceptional ad hoc measures aimed at protecting the pig industry, are described in order to provide a practical and effective approach to combating ASF.