Detection of Echovirus 11 lineage 1 in wastewater samples in Sicily.

We report the presence of Echovirus 11 (E11) in wastewater in Sicily (Southern Italy), since August 2022. Overall, the 5.4 % of sewage samples (7/130) collected in 2022 were positives for E11 and then the percentage of E11-positive sewage samples reached the value of 27.27(18/66) in the first semester of 2023. Phylogenetic analysis of VP1 sequences showed for most E11-positive samples (16/25: 64 %) close genetic correlation (98.4-99.4 % nucleotide identity) to E11 lineage 1 strains involved in recently reported severe neonatal infections.

Biological Specimen Banking as a Time Capsule to Explore the Temporal Dynamics of Norovirus Epidemiology.

Norovirus is recognised as a major cause of epidemic and sporadic acute gastroenteritis (AGE) in all age groups. Information on the genetic diversity of the noroviruses circulating in the 1980s and 1990s, before the development and adoption of dedicated molecular assays, is limited compared with the last decades. Between 1986 and 2020, uninterrupted viral surveillance was conducted in symptomatic children hospitalized with AGE in Palermo, Italy, providing a unique time capsule for exploring the epidemiological and evolutionary dynamics of enteric viruses. A total of 8433 stool samples were tested using real-time RT-PCR. All samples were stored at -20 or -80 °C until processing. In this 35-year long time span, noroviruses of genogroup II (GII) were detected in 15.6% of AGE requiring hospitalization, whilst GI noroviruses were detected in 1.4% of AGE. Overall, the predominant norovirus capsid (Cap) genotype was GII.4 (60.8%), followed by GII.3 (13.3%) and GII.2 (12.4%). Temporal replacement of the GII.4 Cap variants associated with different polymerase (Pol) types were observed over the study period. The chronology of emergence and circulation of the different GII.4 variants were consistent with data available in the literature. Also, for GII.3 and GII.2 NoVs, the circulation of different lineages/strains, differing in either the Cap or Pol genes or in both, was observed. This long-term study revealed the ability of noroviruses to continuously and rapidly modify their genomic makeup and highlights the importance of surveillance activities in vaccine design.

Differing kinetics of anti-spike protein IgGs and neutralizing antibodies against SARS-CoV-2 after Comirnaty (BNT162b2) immunization.

AIMS: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection has had a serious worldwide impact on human health. On December 2020, an immunization campaign with a COVID-19 mRNA vaccine (Comirnaty-BNT162b2 Pfizer-BioNTech) was started in Italy, first targeting healthcare workers (HCWs). This study aims to investigate the antibodies that are response against SARS-CoV-2 vaccine. METHODS AND RESULTS: The kinetics and the persistence of both anti-S1/S2 IgGs and neutralizing antibodies (Nt-Abs) were investigated in 76 HCWs through a 4-month follow-up with multiple testing points starting at the first dose. Temporal analysis of SARS-CoV-2 Abs titre kinetics showed three different stages, with an initial slow growth in the anti-S1/S2 IgGs and Nt-Abs titres, corresponding to the first 4 weeks after the first dose of vaccine, followed by a second stage with peaks in titres, around 35 days after the first dose, and by a third stage (38 to 90-120 days after the first dose) showing a steady decrease in anti-S1/S2 IgGs while Nt-Abs are maintained at stable levels. Moreover, the levels of specific Nt-Abs to SARS-CoV-2 Spike protein are correlated to the anti-S1/S2 IgG titre (R-squared = 0.47; p < 0.001). CONCLUSIONS: The levels of specific Nt-Abs to SARS-CoV-2 Spike protein are correlated to the anti-S1/S2 IgG titre, although Nt-Abs could maintain a more stable titre over the time despite declining IgG Abs titre. SIGNIFICANCE AND IMPACT: This study highlights the kinetics and the persistence of Nt-Abs in HCWs vaccinated with Comirnaty (BNT162b2) Pfizer-BioNTech, and compared the Nt-Abs levels with anti-SARS-CoV-2 S1/S2 IgGs titres during a 4-month follow-up starting at the first dose of vaccine.

Recombinant GII.P16 genotype challenges RT-PCR-based typing in region A of norovirus genome.

OBJECTIVES: In latest years GII.4[P16] and GII.2[P16] noroviruses have become predominant in some temporal/geographical settings. In parallel with the emergence of the GII.P16 polymerase type, norovirus surveillance activity in Italy experienced increasing difficulties in generating sequence data on the RNA polymerase genomic region A, using the widely adopted JV12A/JV13B primer set. Two sets of modified primers (Deg1 and Deg2) were tested in order to improve amplification and typing of the polymerase gene. METHODS: Amplification and typing performance of region A primers was assessed in RT-PCR on 452 GII norovirus positive samples obtained from 2194 stool samples collected in 2016-2019 from children hospitalized with acute gastroenteritis. RESULTS: The use of Deg1 increased the rate of samples types in region A from 49.5% to 81.4% and from 21.9% to 69.7% in 2016 and 2017, respectively. The rate of Deg1 typed samples remained high in 2018 (90.1%), but sharply decreased to 11.8% in 2019. The second primers set, Deg2, was able to increase to 64.9% the rate of 2019 samples typed in region A, while typing efficiently 73.2%, 69%, and 86.4% of samples collected in 2016, 2017 and 2018, respectively. CONCLUSIONS: The plasticity of norovirus genomes requires continuous updates of the primers used for strain characterization.