Genetic characterisation of Measles virus variants identified during a large epidemic in Milan, Italy, March-December 2017.

In 2017, Italy experienced a large measles epidemic with 5408 cases and four deaths. As Subnational Reference Laboratory of the Measles and Rubella surveillance NETwork (MoRoNET), the EpiSoMI (Epidemiology and Molecular Surveillance of Infections) Laboratory (University of Milan) set up rapid and active surveillance for the complete characterisation of the Measles virus (Mv) responsible for the large measles outbreak in Milan and surrounding areas (Lombardy, Northern Italy). The aims of this study were to describe the genetic profile of circulating viruses and to track the pathway of measles transmission. Molecular analysis was performed by sequencing the highly variable 450 nucleotides region of the N gene (N-450) of Mv genome. Two-hundred and ninety-nine strains of Mv were analysed. The phylogenetic analysis showed five different variants, two not previously described in the studied area, belonging to D8 and B3 genotypes. Three events of continuous transmission of autochthonous variants (D8-Osaka, D8-London and B3-Milan variants) and two events of continuous transmission of imported variants (B3-Dublin and D8-Hulu Langat) tracked five different transmission pathways. These pathways outlined two epidemic peaks: the first in April and the second in July 2017. The correlation between Mv variant and the epidemiological data may enable us to identify the sources of virus importation and recognise long-lasting virus transmission pathways.

Measles outbreak on a cruise ship in the western Mediterranean, February 2014, preliminary report.

A measles outbreak occurred in February 2014 on a ship cruising the western Mediterranean Sea. Overall 27 cases were reported: 21 crew members, four passengers.For two cases the status crew or passenger was unknown. Genotype B3 was identified. Because of different nationalities of cases and persons on board,the event qualified as a cross-border health threat. The Italian Ministry of Health coordinated rapid response.Alerts were posted through the Early Warning and Response System.

Analysis of national measles surveillance data in Italy from October 2010 to December 2011 and priorities for reaching the 2015 measles elimination goal.

From 1 October 2010 to 31 December 2011, Italy experienced high measles burden with 5,568 measles cases (37.4% laboratory-confirmed) reported to the enhanced measles surveillance system (cumulative incidence in the 15-month reference period: 9.2/100,000 population). Adolescents and young adults were especially affected, and the median age of cases was 18 years. Most cases (95.8%) were either unvaccinated or incompletely vaccinated. Complications were reported for 20.3% of cases, including 135 cases of pneumonia, seven of encephalitis and one case of Guillain­Barré syndrome. One death occurred in an immunocompromised adult. Over 1,300 cases were hospitalised. Identified priorities for reaching the measles elimination goal include evidence-based interventions such as reminder/recall for both doses of measles vaccine, supplementary immunisation activities aimed at susceptible age cohorts, and vaccinating healthcare workers.

Human case of autochthonous West Nile virus lineage 2 infection in Italy, September 2011.

On 10 September 2011, a patient in his 50s was admitted to hospital in Ancona, Italy, after six days of high fever and no response to antibiotics. West Nile virus (WNV) infection was suspected after tests to determine the aetiology of the fever were inconclusive. On 20 September, WNV-specific IgM and IgG antibodies were detected in the patient's serum. Genomic sequencing of the viral isolate showed that the virus belonged to WNV lineage 2.

Measles in Italy, July 2009 to September 2010.

Outbreaks of measles continue to occur in Italy, as in other European countries. We present here details of cases reported through the Italian enhanced measles surveillance system from July 2009 to September 2010. In total, 2,151 cases were reported, 42% (n=895) of which were laboratory confirmed. The median age of cases was 18 years and 1,709 of 1,856 cases (92%) were unvaccinated. Many cases with complications were reported (n=305), including three with encephalitis. A total of 652 of 1,822 cases (36%) were hospitalised. Molecular characterisation revealed circulation of a limited number of measles virus genotypes (D4, D8 and B3), which is consistent with the current epidemiology of the disease in Italy. A national measles elimination plan was approved in 2003 with the aim of interrupting endemic measles transmission by 2007. Since elimination was not achieved, the target date was recently moved to 2015. The emphasis of the new elimination plan, approved in March 2011, is on strengthening surveillance, implementing evidence based-interventions to increase measles-mumps-rubella vaccine uptake in children, adolescents and young adults, and implementing communication activities related to the vaccine. The strategies proposed by the plan should be implemented fully and appropriately by all regions in order to meet the elimination goal by 2015.

West Nile virus transmission with human cases in Italy, August - September 2009.

In 2009, to date 16 human cases of West Nile neuroinvasive disease (WNND) have been reported in Italy, in three regions: Veneto, Emilia-Romagna and Lombardia. The number of cases is higher compared with last year when nine cases were identified (eight cases of WNND and one case of West Nile fever) and the geographical distribution indicates spread from east to west.

Genetic variability of the measles virus hemagglutinin gene in B3 genotype strains circulating in Northern Italy.

Sequencing the whole measles virus hemagglutinin (H) gene, in conjunction with a 450-nucleotide region of the nucleoprotein gene (N-450), is helpful for the identification of new genotypes and as an auxiliary in outbreak characterization. In addition, it is essential to be able to predict the antigenic changes of the H protein to gain a better monitoring of the response to the vaccine. In this study, we obtained the full-length H gene sequences from 19 measles virus (MV) strains belonging to two B3 genotype variants circulating in Lombardy (Northern Italy) between July 2015 and February 2016 and evaluated the variability of the whole MV-H gene. Furthermore, we compared the obtained H amino acid sequences to all MV sequences available in the GenBank database (n = 1152 in total) and analyzed the amino acid substitutions in the H protein within clades where the Italian strains were included. We identified a higher variability in the H gene compared to the N-450 region and our results support previous studies, highlighting that the H gene is more informative for characterizing the MV B3 genotype than the N-450 sequence. Some of the amino acid substitutions were fixed in the viral population and, remarkably, some of the amino acid substitutions were typically present only in the Italian sequences. Accumulating further molecular information about MV-H gene will be necessary to enable in-depth analyses of the variability of this gene in the vaccinated population.

Infection with chikungunya virus in Italy: an outbreak in a temperate region.

BACKGROUND: Chikungunya virus (CHIKV), which is transmitted by Aedes spp mosquitoes, has recently caused several outbreaks on islands in the Indian Ocean and on the Indian subcontinent. We report on an outbreak in Italy. METHODS: After reports of a large number of cases of febrile illness of unknown origin in two contiguous villages in northeastern Italy, an outbreak investigation was done to identify the primary source of infection and modes of transmission. An active surveillance system was also implemented. The clinical case definition was presentation with fever and joint pain. Blood samples were gathered and analysed by PCR and serological assays to identify the causal agent. Locally captured mosquitoes were also tested by PCR. Phylogenetic analysis of the CHIKV E1 region was done. FINDINGS: Analysis of samples from human beings and from mosquitoes showed that the outbreak was caused by CHIKV. We identified 205 cases of infection with CHIKV between July 4 and Sept 27, 2007. The presumed index case was a man from India who developed symptoms while visiting relatives in one of the villages. Phylogenetic analysis showed a high similarity between the strains found in Italy and those identified during an earlier outbreak on islands in the Indian Ocean. The disease was fairly mild in nearly all cases, with only one reported death. INTERPRETATION: This outbreak of CHIKV disease in a non-tropical area was to some extent unexpected and emphasises the need for preparedness and response to emerging infectious threats in the era of globalisation.

Arboviruses in Italy.

A brief review of the arboviruses isolated In Italy is presented and discussed. Some of the Arboviruses considered in this paper are endemic in the country and are transmitted by arthropods that play actually a role of vectors, (sand flyes, hard ticks and mosquitoes); other arboviruses, sporadically isolated, are potential agents of emerging human or zoonotic diseases.

Cluster of measles cases in the Roma/Sinti population, Italy, June-September 2006.

Three clusters of measles cases occurred between June and September 2006, in the Roma/Sinti populations in three different Italian regions: the Bolzano-South Tyrol in northern Italy; Lazio in central Italy; and the island of Sardinia in the southwest.

The transmembrane domain of hepatitis C virus E1 glycoprotein induces cell death.

The E1 protein of hepatitis C virus (HCV) shows the ability to induce cell lysis by the alteration of membrane permeability when expressed in Escherichia coli cells. This function seems to be an intrinsic property of a C-terminal hydrophobic region of E1 as permeability changes and cell lysis can be blocked by mutagenesis of specific amino acids in this domain. To establish whether the expression of E1 protein and its C-terminal domain was able to induce cell death also in eukaryotic cell, we cloned HCV sequences expressing the full-length E1 (E383), the C-terminal domain (SVP) and a mutant lacking the C-terminal region (E340) in the pRC/CMV expression vector. HepG2 cell line was co-transfected with empty vector or HCV expression plasmids and a reporter vector that expressed beta-galactosidase (beta-gal) to visualize co-transfected blue cells. At 60 h after transfection, the loss of blue cells, considered as a measure of cell death, was 31.5 and 64.3% for the E1 and SVP clones. On the contrary, the number of blue cells after transfection with E340 plasmid was similar to that observed with the control vector. The analysis by the terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling (TUNEL) assay revealed an increased number of apoptotic cells at 48 h after transfection with E1 and SVP clones. Furthermore, cells transfected with SVP revealed a typical internucleosomal DNA fragmentation and the activation of caspase-3-like proteases as the specific inhibitor Ac-DEVD-CHO peptide partially blocked SVP apoptosis. These data indicate that the intracellular expression of HCV E1 protein and its C-terminal domain induces an apoptotic response in human hepatoma cell line.

Circulation of West Nile virus lineage 1 and 2 during an outbreak in Italy.

In 2011, from 26 September to 16 October, a small outbreak of West Nile virus (WNV) disease occurred on the island of Sardinia (Italy). According to the national case definition, six cases with acute neurological disease were confirmed in hospitalized patients, and four of them died; one of these was only 34 years old. In two case, WNV RNA was detected in urine, suggesting renal involvement. Sequence analysis showed lineage 1 and 2 circulation.

Humoral response in Toscana virus acute neurologic disease investigated by viral-protein-specific immunoassays.

The Toscana virus (family Bunyaviridae, genus Phlebovirus) is the only sandfly-transmitted virus that demonstrates neurotropic activity. Clinical cases ranging from aseptic meningitis to meningoencephalitis caused by Toscana virus are yearly observed in central Italy during the summer, and several cases have been reported among tourists returning from zones of endemicity (Italy, Portugal, Spain, and Cyprus). In Toscana virus patients, immunoglobulin M (IgM) antibodies, usually present at the onset of symptoms, can reveal elevated titers by enzyme-linked immunosorbent assay and can persist for at least 1 year. IgG antibodies can be absent at the onset of symptoms: titers rise in convalescent sera and persist for many years. At least five proteins have been identified in Toscana virus-infected cells: nucleoprotein N, glycoproteins G1 and G2, a large protein (L) assumed to be a component of the polymerase, and two nonstructural proteins, NSm and NSs. We report results of a study on the antibody response to individual viral proteins in patients with Toscana virus-associated acute neurologic disease. Immunoblotting and semiquantitative radioimmunoprecipitation assay (RIPA) allow identification of nucleoprotein N as the major antigen responsible for both IgM and IgG responses. Antibodies to proteins other than nucleoprotein N are detected only by RIPA. Antibodies to glycoproteins are detected in about one-third of patients, and whereas their presence always predicts neutralization, some serum samples with neutralizing activity have undetectable levels of antibodies to G1-G2. Antibodies to nonstructural proteins NSm and NSs are also identified. The results obtained raise some questions about antigenic variability and relevant neutralization epitopes of Toscana virus.