Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo'.

On 21 February 2020, a resident of the municipality of Vo', a small town near Padua (Italy), died of pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection1. This was the first coronavirus disease 19 (COVID-19)-related death detected in Italy since the detection of SARS-CoV-2 in the Chinese city of Wuhan, Hubei province2. In response, the regional authorities imposed the lockdown of the whole municipality for 14 days3. Here we collected information on the demography, clinical presentation, hospitalization, contact network and the presence of SARS-CoV-2 infection in nasopharyngeal swabs for 85.9% and 71.5% of the population of Vo' at two consecutive time points. From the first survey, which was conducted around the time the town lockdown started, we found a prevalence of infection of 2.6% (95% confidence interval (CI): 2.1-3.3%). From the second survey, which was conducted at the end of the lockdown, we found a prevalence of 1.2% (95% CI: 0.8-1.8%). Notably, 42.5% (95% CI: 31.5-54.6%) of the confirmed SARS-CoV-2 infections detected across the two surveys were asymptomatic (that is, did not have symptoms at the time of swab testing and did not develop symptoms afterwards). The mean serial interval was 7.2 days (95% CI: 5.9-9.6). We found no statistically significant difference in the viral load of symptomatic versus asymptomatic infections (P = 0.62 and 0.74 for E and RdRp genes, respectively, exact Wilcoxon-Mann-Whitney test). This study sheds light on the frequency of asymptomatic SARS-CoV-2 infection, their infectivity (as measured by the viral load) and provides insights into its transmission dynamics and the efficacy of the implemented control measures.

Tracing the SARS-CoV-2 infection on the ocular surface: Overview and preliminary corneoscleral transcriptome sequencing.

COVID-19's impact on the ocular surface has already been recognized, however the molecular mechanisms induced by the infection on the ocular surface are still unclear. The aim of this paper is to provide a first overview of the transcriptional perturbations caused by SARS-CoV-2 on the ocular surface by analyzing gene expression profile of corneoscleral ring samples from post-mortem SARS-CoV-2 positive donors (PD). The presence of SARS-CoV-2 on the ocular surface, in tears and corneal tissues has rarely been detected in infected individuals in both the presence and the absence of ocular manifestations. In this preliminary study, 6 human corneoscleral tissues of 3 PD and two tissues from a negative donor (CTRL) were obtained at the local eye bank. The presence of genomic and sub-genomic SARS-CoV-2 RNAs was assessed by qRT-PCR, while transcriptome analysis (RNA-sequencing) was performed by Illumina. Principal Component Analysis (PCA), search for differentially expressed genes (DEGs) and Gene Ontology (GO)-enrichment analysis were performed. Three samples from PD were found positive for SARS-CoV-2 genomic RNA, although the absence of sub-genomic RNAs indicated an inactive virus. PCA analysis grouped 3 different clusters, one including CTRL, and the other two including, respectively, PD with undetected SARS-CoV-2 (PD-SARS-neg) and PD with detected SARS-CoV-2 (PD-SARS-pos). The DEGs in common with the 2 PD clusters included several genes associable to the interferon pathway, such as ADAMTS4, RSAD2, MMP1, IL6, ISG15 and proinflammatory cytokines. Among the down-regulated genes we found AQP5. GO analysis revealed 77 GO terms over-represented in PD-SARS-neg vs. CTRL, and 17 GO terms in PD-SARS-pos vs. CTRL. The presence of SARS-CoV-2 RNA and RNA-sequencing reads in ocular surface tissues supports the possibility that the eye acts as an entry route. The modulation of early responsive genes, together with several ISGs suggests a potential protective responsiveness of the ocular tissues to SARS-CoV-2.

Impact of Sars-CoV-2 pandemic on the Veneto Region multitissue bank activity.

Covid pandemic affected donation activities worldwide, especially for living donation due to the lack of elective surgery. Moreover, the number of heart-beating and non-heart beating donors has recorded a decrease. Fondazione Banca dei Tessuti di Treviso (FBTV) is a non-profit healthcare organisation, located in Veneto Region, tasked with procurement, processing, preserving, validating and distributing human tissue for clinical use. During Covid-19 outbreak, operations in FBTV have never stopped and a great effort was required to maintain a standard trend of activity. The aim of this study was to describe the impact of Sars-CoV-2 on the activity of a multitissue bank in Italy. Moreover, we investigated the presence of the virus in tissues retrieved from two Sars-CoV-2 positive cadaver donors. Our survey demonstrated that the transplantation network of Veneto Region has positively reacted to the pandemic scenario, thanks to the effort of all personnel involved. Statistical analyses underlined that most of the activities of the tissue bank were unaffected during the Sars-CoV-2 pandemic.

The first familial cluster of the B.1.1.7 variant of SARS-CoV-2 in the northeast of Italy.

PURPOSE: We report on the first identified cluster of the B.1.1.7 variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the northeast of Italy. METHODS: The cluster was recognized in January 2021 with an epidemiological started from the hospitalization of a 68-year-old man suffering from coronavirus disease 2019 (COVID-19) related pneumonia and we surprisingly found three families involved in the same cluster. RESULTS: We retrospectively rebuilt the pathway of infection and performed a virological analysis. CONCLUSION: This allow us to make clear the very high attack rate and the great infective capacity of this B.1.1.7 variant of SARS-CoV-2.

SARS-CoV-2 RNA identification in nasopharyngeal swabs: issues in pre-analytics.

Objectives: The direct identification of SARS-CoV-2 RNA in nasopharyngeal swabs is recommended for diagnosing the novel COVID-19 disease. Pre-analytical determinants, such as sampling procedures, time and temperature storage conditions, might impact on the end result. Our aim was to evaluate the effects of sampling procedures, time and temperature of the primary nasopharyngeal swabs storage on real-time reverse-transcription polymerase chain reaction (rRT-PCR) results. Methods: Each nasopharyngeal swab obtained from 10 hospitalized patients for COVID-19 was subdivided in 15 aliquots: five were kept at room temperature; five were refrigerated (+4 °C); five were immediately mixed with the extraction buffer and refrigerated at +4 °C. Every day and for 5 days, one aliquot per condition was analyzed (rRT-PCR) for SARS-CoV-2 gene E and RNaseP and threshold cycles (Ct) compared. To evaluate manual sampling, 70 nasopharyngeal swabs were sampled twice by two different operators and analyzed separately one from the other. Results: A total of 6/10 swabs were SARS-CoV-2 positive. No significant time or storage-dependent variations were observed in SARS-CoV-2 Ct. Re-sampling of swabs with SARS-CoV-2 Ct lower than 33 resulted in highly reproducible results (CV=2.9%), while a high variability was observed when Ct values were higher than 33 (CV=10.3%). Conclusions: This study demonstrates that time and temperature of nasopharyngeal swabs storage do not significantly impact on results reproducibility. However, swabs sampling is a critical step, and especially in case of low viral load, might be a potential source of diagnostic errors.

Universal screening of high-risk neonates, parents, and staff at a neonatal intensive care unit during the SARS-CoV-2 pandemic.

Since February 21, 2020, SARS-CoV-2 has spread exponentially worldwide. Neonatal patients needing intensive care are considered a vulnerable population. To report the results of a policy based on multi-timepoint surveillance for SARS-CoV-2 of all neonates admitted to the neonatal intensive care unit (NICU), their parents, and all healthcare providers in a part of Italy with a high prevalence of the infection. Observational study conducted from 21 February to 21 April 2020. Intervention consisted of (a) parental triage on arrival at the neonatal ward; (b) universal testing with nasopharyngeal swabs and blood testing for SARS-CoV-2 IgM and IgG antibodies; (c) use of continuous personal protective equipment at the NICU by parents and staff. A total of 6726 triage procedures were performed on 114 parents, and 954 nasopharyngeal swabs were collected from 226 individuals. Five (2.2%) asymptomatic individuals (2 parents and 3 healthcare providers) tested positive on nasopharyngeal swabs and were kept isolated for 14 days. Of 75 admitted newborn, no one tested positive on nasopharyngeal swabs or antibody tests. Three parents presented with fever or flu-like symptoms at triage; they tested negative on swabs.Conclusion: With universal screening of neonates, parents, and staff, there were no cases of SARS-CoV-2 infection among the neonates admitted to a NICU in an area with a high incidence of SARS-CoV-2. Our experience could be usefully compared with other strategies with a view to developing future evidence-based guidelines for managing high-risk neonates in case of new epidemics. What is Known: • The novel coronavirus named SARS-CoV-2 has since spread worldwide at a remarkable rate, with more than 2.5 million confirmed cases. • Pediatric population may be less affected from COVID-19 than adult population but infants and newborn babies seem to be more vulnerable to SARS-CoV-2 infection. What is New: • Using an approach based on triage; testing with nasopharyngeal swabs and serology; and use of personal protective equipment, there were no cases of SARS-CoV-2 infection among neonates in a NICU in a high incidence of SARS-CoV-2 area. • Positive and asymptomatic individuals were identified and isolated early allowing the containment of infection's spread among healthcare providers and parents.

The complete genome sequence analysis of West Nile virus strains isolated in Slovakia (central Europe).

The present study reports the first complete genome sequence analysis of West Nile virus (WNV) strains isolated from brain samples from raptors. The results prove the circulation of closely related WNV lineage II strains in central Europe and genetic analysis revealed seven amino acid substitutions in structural (PrM3, E159 and E231) and in non-structural (NS1109, NS5259, NS5310 and NS5600) proteins. Observed amino acid substitutions Phe3 and Ser231 were common only within the lineage VII Koutango strain isolated from Rhipicephalus guilhoni tick in Senegal. Further research could reveal whether these substitutions influence the biological properties of WNV, including virulence and neuroinvasiveness.

Antiviral treatment and virological monitoring of oseltamivir-resistant influenza virus A(H1N1)pdm09 in a patient with chronic B lymphocytic leukemia.

We report the virological monitoring and the antiviral therapy adopted for the treatment of a patient affected by chronic B lymphocytic leukemia, who experienced a severe pneumonia with long-term shedding of influenza virus A(H1N1)pdm09, characterized by an early development of oseltamivir resistance.

West Nile virus infection in individuals with pre-existing Usutu virus immunity, northern Italy, 2018.

In 2018, there was a large West Nile virus (WNV) outbreak in northern Italy. We observed five atypical cases of WNV infection that were characterised by the presence of WNV RNA and WNV IgG at the time of diagnosis, but no IgM response during follow-up. Neutralisation assays demonstrated pre-existing Usutu virus immunity in all patients. Besides challenging diagnosis, the immunological crosstalk between the two viruses warrants further investigation on possible cross-protection or infection enhancement effects.

Clinical and virological findings in patients with Usutu virus infection, northern Italy, 2018.

BackgroundUsutu virus (USUV) is a mosquito-borne flavivirus, which shares its transmission cycle with the phylogenetically related West Nile virus (WNV). USUV circulates in several European countries and its activity has increased over the last 5 years.AimTo describe human cases of USUV infection identified by surveillance for WNV and USUV infection in the Veneto Region of northern Italy in 2018.MethodsFrom 1 June to 30 November 2018, all cases of suspected autochthonous arbovirus infection and blood donors who had a reactive WNV nucleic acid test were investigated for both WNV and USUV infection by in-house molecular methods. Anti-WNV and anti-USUV IgM and IgG antibodies were detected by ELISA and in-house immunofluorescence assay, respectively; positive serum samples were further tested by WNV and USUV neutralisation assays run in parallel.ResultsEight cases of USUV infection (one with neuroinvasive disease, six with fever and one viraemic blood donor who developed arthralgia and myalgia) and 427 cases of WNV infection were identified. A remarkable finding of this study was the persistence of USUV RNA in the blood and urine of three patients during follow-up. USUV genome sequences from two patients shared over 99% nt identity with USUV sequences detected in mosquito pools from the same area and clustered within lineage Europe 2.ConclusionsClinical presentation and laboratory findings in patients with USUV infection were similar to those found in patients with WNV infection. Cross-reactivity of serology and molecular tests challenged the differential diagnosis.

Cytomegalovirus, Epstein-Barr virus and human herpesvirus 8 salivary shedding in HIV positive men who have sex with men with controlled and uncontrolled plasma HIV viremia: a 24-month longitudinal study.

BACKGROUND: This longitudinal study described Cytomegalovirus (CMV) DNA, Epstein-Barr (EBV) DNA and human herpesvirus 8 (HHV-8) DNA asymptomatic salivary shedding in HIV-positive men who have sex with men (MSM). We aimed to 1-analyze frequency and persistence of herpesvirus shedding, 2-correlate herpesvirus positivity and HIV viroimmunological parameters and 3-assess the association between HIV-RNA suppression and herpesvirus replication. METHODS: Herpesvirus DNA was tested with an in-house real-time PCR in 2 salivary samples obtained at T0 and T1 (24 months after T0). HIV-RNA was evaluated in the 24 months prior to T0 and in the 24 months prior to T1; MSM were classified as successfully suppressed patients (SSPs), viremic patients (VPs) and partially suppressed patients (PSPs). EBV DNA load was classified as low viral load (EBV-LVL, value ≤10,000 copies/ml) and as high viral load (EBV-HVL,> 10,000 copies/ml). Mann-Whitney U test tested the difference of the median between groups of patients. Chi-squared test and Fisher's exact test compared categorical variables according to the frequencies. Kruskal-Wallis test compared continuous data distributions between levels of categorical variables. RESULTS: Ninety-two patients (median CD4+ count 575 cells/mm3, median nadir 330 CD4+ cells/mm3) were included: 40 SSPs,33 VPs and 19 PSPs. The more frequently single virus detected was EBV, both at T0 and at T1 (in 67.5 and 70% of SSPs, in 84.8 and 81.8% of VPs and in 68.4 and 73.7% of SPSs) and the most frequently multiple positivity detected was EBV + HHV-8. At T1, the percentage of CMV positivity was higher in VPs than in SSPs (36.4% vs 5%, p < 0.001), the combined shedding of HHV-8, CMV and EBV was present only in VPs (15.1%, p = 0.01 respect to SSPs) and no VPs confirmed the absence of shedding found at T0 (vs 17.5% of SSPs, p = 0.01). EBV-HVL was more frequent in VPs than in SSPs: 78.6% at T0 (p = 0.03) and 88.9% at T1 (p = 0.01). CONCLUSIONS: The relationship between uncontrolled plasma HIV viremia and CMV, EBV, and HHV-8 shedding is multifaceted, as demonstrated by the focused association with EBV DNA load and not with its frequency and by the persistent combined detection of two oncogenic viruses as EBV and HHV-8 regardless of HIV virological control.

Epstein-Barr and cytomegalovirus DNA salivary shedding correlate with long-term plasma HIV RNA detection in HIV-infected men who have sex with men.

The aim of the study was to evaluate cytomegalovirus (CMV) and Epstein-Barr virus (EBV) DNA salivary shedding in HIV-positive men who have sex with men (MSM) and to determine whether viro-immunological parameters and long-term (24 months) plasma HIV RNA (pHIV) detection may predict herpesviruses replication. A total of 193 HIV-positive MSM were consecutively recruited (mean CD4+ cell count 607 cells/mm(3) and mean nadir value 333 cells/mm(3) ); pHIV was analyzed for 24 months prior to saliva sampling: patients were categorized as successfully suppressed (SS) and not suppressed (NS). The EBV viral load was categorized as high viral load (HVL), intermediate (IVL), or low (LVL), CMV DNA as positive or negative. NS patients experienced both herpesviruses detectability more frequently respect to SS patients (P = 0.034); conversely, no salivary shedding was more frequent in SS patients (P = 0.014). HVL EBV was more frequent in NS patients than in SS subjects (P = 0.038 for isolated EBV detection and P = 0.001 when CMV shedding was associated). NS subjects with HVL EBV had a median pHIV of 43,820 copies/ml, significantly higher respect to IVL and LVL patients (P = 0.027 and P = 0.0005, respectively). CMV shedding was mostly associated to EBV shedding. NS patients showed a significantly higher frequency of saliva HVL EBV detection compared to SS patients; moreover, NS patients with HVL EBV had a higher pHIV respect to those with IVL and LVL shedding. Our results suggest that a successful pHIV suppression could reduce the burden of salivary EBV replication and likely the risk of herpesviruses-related cancers.

Isolation of infectious Zika virus from saliva and prolonged viral RNA shedding in a traveller returning from the Dominican Republic to Italy, January 2016.

We report the isolation of infectious Zika virus (ZIKV) in cell culture from the saliva of a patient who developed a febrile illness after returning from the Dominican Republic to Italy, in January 2016. The patient had prolonged shedding of viral RNA in saliva and urine, at higher load than in blood, for up to 29 days after symptom onset. Sequencing of ZIKV genome showed relatedness with strains from Latin America.

Infection dynamics in a traveller with persistent shedding of Zika virus RNA in semen for six months after returning from Haiti to Italy, January 2016.

We describe the dynamics of Zika virus (ZIKV) infection in a man in his early 40s who developed fever and rash after returning from Haiti to Italy, in January 2016. Follow-up laboratory testing demonstrated detectable ZIKV RNA in plasma up to day 9 after symptom onset and in urine and saliva up to days 15 and 47, respectively. Notably, persistent shedding of ZIKV RNA was demonstrated in semen, still detectable at 181 days after onset.

Prevalence of Klebsiella pneumoniae strains producing carbapenemases and increase of resistance to colistin in an Italian teaching hospital from January 2012 To December 2014.

BACKGROUND: The aim of this study was to characterize the spread of carbapenemase-producing Klebsiella pneumoniae (CPKP) in a tertiary level hospital using ongoing active surveillance with rectal swab cultures. Furthermore, this study analyzed the presence of CPKP in the clinical samples (CS) of a single patient as well as the evolution of Colistin-sensitive strains (CoS) to Colistin-resistant strains (CoR). METHODS: This study was performed from January 1, 2012 to December 31, 2014. In 2012, a survey was conducted in the Intensive Care Department. In autumn 2013, active monitoring was extended to the Surgery Department, and since mid-2014, the surveillance has included the Medical Department as well. Only the first isolated strain from each patient was included. Antimicrobial susceptibility testing was performed on CPKP isolates: Klebsiella pneumoniae carbapenemase, oxacillinase-48, Verona integron-encoded metallo-ß-lactamase and New Delhi metallo-ß-lactamase were detected using a validated in-house PCR method, and multilocus sequence typing (MLST) was used to investigate the clonal transmission of strains. RESULTS: A total of 15,104 patients were included in the study, and 496 consecutive non-replicated strains of CPKP were collected: 149 strains were collected in 2012 (39 [26.2 %] from surveillance rectal swabs [SRS]), 133 strains were collected in 2013 (70 [52.6 %] from SRS) and 214 strains were collected in 2014 (164 [76.6 %] from SRS). We observed a significant increase in the percentage of positive SRS cases in 2014 relative to 2013 and 2012 (p = 0.0001 and p = 0.0172, respectively) and in the proportion of CPKP first isolated by SRS relative to those identified by CS (p < 0.0001). Among all available samples, the number of CoR isolated from SRS was higher in 2013 and 2014 compared with 2012 (p = 0.0019 and p = 0.008, respectively). ST-258 and ST-512 were more prevalent in the tested specimens, and a new single locus variant (SLV) of ST-512 (ST-745) was isolated. CONCLUSIONS: The results of this 3-year study of 15,104 patients highlight the clinical relevance of antimicrobial resistance as well as the drug-selection pressure of colistin therapy. The active surveillance in the three different departments increased the level of CPKP cases isolated by SRS.

Isolation of West Nile virus from urine samples of patients with acute infection.

This study demonstrated that West Nile virus (WNV) excreted in the urine of patients with acute infection can be isolated in cell cultures. In addition, the protocols for WNV isolation from urine samples were standardized, and factors that may affect the efficiency of WNV isolation were identified.

Excretion of West Nile virus in urine during acute infection.

Detection of West Nile virus (WNV) RNA in urine has been anecdotally described and proposed for the diagnosis of WNV infection. This study reports the routine use of real-time reverse-transcription polymerase chain reaction for the detection of WNV RNA in urine to support diagnosis of WNV infection during the large outbreak that occurred in northeastern Italy in 2012. Fourteen of 32 patients (43.8%) with symptomatic WNV infection, defined as neuroinvasive disease and fever, had detectable WNV RNA in urine at the time of diagnosis, at a higher rate and load and for a longer time than detection of WNV RNA in blood. Detection of WNV RNA in urine was less frequent (2 of 14 patients [14.2%]) in blood donors in whom WNV infection was identified by WNV nucleic acid amplification testing. Infectious virus was isolated from the urine of a patient with neuroinvasive disease and a high WNV RNA load in urine.

Genomic comparative analysis and gene function prediction in infectious diseases: application to the investigation of a meningitis outbreak.

BACKGROUND: Next generation sequencing (NGS) is being increasingly used for the detection and characterization of pathogens during outbreaks. This technology allows rapid sequencing of pathogen full genomes, useful not only for accurate genotyping and molecular epidemiology, but also for identification of drug resistance and virulence traits. METHODS: In this study, an approach based on whole genome sequencing by NGS, comparative genomics, and gene function prediction was set up and retrospectively applied for the investigation of two N. meningitidis serogroup C isolates collected from a cluster of meningococcal disease, characterized by a high fatality rate. RESULTS: According to conventional molecular typing methods, all the isolates had the same typing results and were classified as outbreak isolates within the same N. meningitidis sequence type ST-11, while full genome sequencing demonstrated subtle genetic differences between the isolates. Looking for these specific regions by means of 9 PCR and cycle sequencing assays in other 7 isolates allowed distinguishing outbreak cases from unrelated cases. Comparative genomics and gene function prediction analyses between outbreak isolates and a set of reference N. meningitidis genomes led to the identification of differences in gene content that could be relevant for pathogenesis. Most genetic changes occurred in the capsule locus and were consistent with recombination and horizontal acquisition of a set of genes involved in capsule biosynthesis. CONCLUSIONS: This study showed the added value given by whole genome sequencing by NGS over conventional sequence-based typing methods in the investigation of an outbreak. Routine application of this technology in clinical microbiology will significantly improve methods for molecular epidemiology and surveillance of infectious disease and provide a bulk of data useful to improve our understanding of pathogens biology.