To report a descriptive analysis of the virological results of Influenza-like illness (ILI) surveillance, comparing the frequency of detection of respiratory viruses during the pre-pandemic ...(2018-2019) and SARS-CoV-2 pandemic (2020-2021) winter seasons in Lombardy (Northern Italy).
From week 46 to week 17 of the following year, nasal-pharyngeal swabs (NPS) collected from ILIs were tested for influenza viruses (IV), RSV, rhinovirus and enterovirus with specific real-time RT-PCR assays. In 2020-2021, SARS-CoV-2 molecular detection was also included.
464 and 446 NPS were collected in 2018-2019 and 2020-2021, respectively. Sex distribution was similar between these two seasons (males: 51.5% vs 47%, P=0.165), while mean age was statistically higher in 2020-2021 (28.2 years IQR: 40.5 vs. 43.6 years IQR: 32.6, P<0.0001). ILI incidence was significantly higher in 2018/19 compared with 2020/21 season season (5.4/1,000 inhabitants vs. 1.9/1,000 inhabitants, P< 0.0001.ILI cases <15 years were less reported in 2020-2021 than in 2018-2019 season (P<0.0001). Contrary, those >15 years were more reported in 2020-2021 than in 2018-2019 (15-44 years, P=0.008; 45-64 years, P=0.002; ≥65 years, P<0.0001). In 2018-2019, IV and RSV accounted for 55% and 10% of ILIs, whereas in 2020-2021 no circulation of these viruses was observed. Enterovirus detections decreased from 3.4% in 2018-2019 to 0.4% in 2020-2021 (P=0.01), while rhinoviruses were detected at higher frequency in the latter season (8.6% vs. 11.9%, P=0.07). SARS-CoV-2 was detected in 25.3% of NPS in 2020-2021.
Since the beginning of the pandemic, non-pharmaceutical measures, including use of face-masks, was massively applied to contrast SARS-CoV-2 spread. This dramatically reduced the incidence of ILI, the circulation of SARS-CoV-2 and other respiratory viruses (such as IV and RSV) transmitted by droplets, but did not reduce rhinovirus detection, which continued to circulate in 2020-2021 season. ILIs surveillance has demonstrated to be able to capture changes in the epidemiology of respiratory viruses and it should be sustained and improved to increase the capture of ILI remained with unknown etiology.
Salmonella Give is a rare serotype across Europe. In October 2016, a national outbreak of S. Give occurred in Malta. We describe the epidemiological, environmental, microbiological and veterinary ...investigations. Whole-genome sequencing (WGS) was performed on human, food, environmental and veterinary isolates. Thirty-six human cases were reported between October and November 2016, 10 (28%) of whom required hospitalisation. Twenty-six (72%) cases were linked to four restaurants. S. Give was isolated from ready-to-eat antipasti served by three restaurants which were all supplied by the same local food manufacturer. Food-trace-back investigations identified S. Give in packaged bean dips, ham, pork and an asymptomatic food handler at the manufacturer; inspections found inadequate separation between raw and ready-to-eat food during processing. WGS indicated two genetically distinguishable strains of S. Give with two distinct clusters identified; one cluster linked to the local food manufacturer and a second linked to veterinary samples. Epidemiological, environmental and WGS evidence pointed towards cross-contamination of raw and ready-to-eat foods at the local manufacturer as the likely source of one cluster. Severity of illness indicates a high virulence of this specific serotype. To prevent future cases and outbreaks, adherence to food safety practices at manufacturing level need to be reinforced.
The value of SARS-CoV-2 monitoring in urban wastewater samples (WWS) for surveillance of virus spread at a population-wide level has been largely demonstrated. Aim of this study was to optimize an ...analytical workflow to detect SARS-CoV-2 RNA in WWS and to monitor SARS-CoV-2 spread during the first wave of COVID-19 epidemic (March–June 2020) in Lombardy, northern Italy.
The workflow consisted in WWS concentration by using PEG-8000 precipitation, a modified RNA extraction (QIAamp MinElute Virus Spin Kit; QIAGEN) and a one-step real-time RT-PCR detecting two portions of the N gene of SARS-CoV-2. Composite 24-hour WWS were collected once a week at the inlet of 8 wastewater treatment plants (WWTPs) with an overall catchment of 2,276,000 inhabitants, located in representative COVID-19 hotspots in Lombardy, from the end of March to mid-June 2020. 107 WWS were obtained and analysed. SARS-CoV-2 RNA copies/L/WWS were multiplied by the flow rate of each WWTP (m3/day) and the obtained load (copies/day/1,000 people) was normalized to the number of inhabitants served by WWTPs.
The optimized workflow allowed to identify 1E+3 copies/mL of SARS-CoV-2 in concentrated WWS with a turnaround time of 8 hours. Overall, the presence of SARS-CoV-2 RNA was identified in 65/107 WWS (61%). The highest rate of positive WWS (78.7%; 26/33) was identified in the Bergamo province, that was the epicentre during the first wave of COVID-19 epidemic (March-June 2020) in Lombardy. The highest amount of SARS-CoV-2 RNA was identified in late March/early April, when the overall viral load reflecting the number of individuals shedding the virus ranged from 9.3E+10 copies/day/1,000 people to 8.2E+8 copies/day/1,000 people. Since the end of May, WWS tested negative to SARS-CoV-2 detection.
According to the epidemiological features of the first wave of SARS-CoV-2 epidemic in Lombardy, the highest amount of SARS-CoV-2 RNA was detected in WWS collected in the areas most affected by COVID-19 (i.e. Bergamo province). This optimized workflow of WWS surveillance can help assessing the real number of individuals – both symptomatic and asymptomatic – able to spread the virus and appraising the effect of preventive measures.
Aims
Human Enteroviruses (HEVs) infections have a significant impact on public health, being implicated in outbreaks of meningitis, encephalitis, hand‐foot‐mouth disease and other acute and chronic ...manifestation. In the strategic plan for poliomyelitis eradication, the environmental surveillance of poliovirus (PV) has been identified by the World Health Organization (WHO) as an activity that can complement the surveillance of polio. Having wastewater samples available for PV surveillance allows us to study nonpolio enteroviruses (NPEVs) circulating in the study population, which are widely spread.
Methods and Results
This study was carried out according to the WHO guidelines for environmental surveillance of PV and analysed the circulation of PV and NPEVs through the isolation of viruses in cell cultures in Milan area; from 2006 to 2010, 321 wastewater samples were collected, regularly over time, at the inlet of three diverse waste water treatment plants (WWTPs).
Culturable HEVs were isolated in 80% of sewage samples: all isolates belonged to the HEV‐B group and those circulating more intensely were CVB5 and Echo 6, while CVB4 was the predominant serotype found in 2010. In this study, two type 2 PVs were isolated, both characterized as Sabin like.
Conclusion
Environmental monitoring of HEVs in Milan has proved to be an interesting tool to investigate the circulation and distribution of viruses.
Significance and Impact of the Study
The detection of PV and other NPEV could be predictive of possible re‐emergence of these viruses with an impact on public health. NPEV monitoring could also be a powerful public health tool to investigate the possible role of NPEV in different clinical manifestations.
Enterovirus (EV) and parechovirus (PeV) can either infect humans asymptomatically or can cause gastroenteritis, respiratory symptoms and, sometimes, severe disease. As the number of newly identified ...EV and PeV genotypes keeps increasing, diagnostic methods need to be updated. To this end, we described a novel multiplex one-step real-time RT-PCR to detect EV and human PeV (HPeV) simultaneously in fecal samples collected from children with rotavirus group A (RV-A)-related gastroenteritis.
The specificity and sensitivity of the EV/HPeV realtime RT-PCR were evaluated with two 2011 Quality Control for Molecular Diagnostics (QCMD) panels for EV and HPeV detection. RNA was extracted from 111 RV-A-positive fecal samples collected from children up to 5 years of age who had been hospitalized for gastroenteritis from September 2010 to August 2011.
The EV/HPeV real-time RT-PCR showed a 100% sensitivity and specificity for EV and 91% and 91.7% for HPeV, respectively. Of the 111 RV-A-positive stool specimens, 28 (25.2%) were EV-positive and 7 (6.3%) were HPeV-positive. No clinical differences between children with single or double infections were observed.
In our study, the frequency of EV and HPeV infections was surprisingly high, thus underlining the importance of including EV and HPeV detection in diagnostic panels. The multiplex real-time RT-PCR presented in this paper can therefore be a useful method in a diagnostic setting.
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