An overview on the use of ultraviolet radiation to disinfect air and surfaces.

Background and aim Ultraviolet radiation (UV) is the portion of the electromagnetic spectrum of wavelengths between 200 and 400 nm divided into three bands called UVA, UVB and UVC. Due its well-described antimicrobial activity, UVC can represent a useful tool for disinfect surfaces, water, and air. The aim of this study was to illustrate the studies over time ultraviolet germicidal irradiation (UVGI) to disinfect air and surfaces. Methods Articles on Scopus published until April 14, 2023, were considered. Many issues involving UV were deepened crosschecking with e.g., "air", "surfaces", "disinfection", "bacteria", "fungi", "operating theatres". According to the case, the following variables were considered: years and related number of articles, sources of publications, subject areas, type of document published, type of journal, nationalities of the authors. Results Since 30's, 287 448 articles on UV have been published. Among UVGI, 22 159 articles covered bacteria issue, followed by fungi and viruses with about 12000 both. UVGI was addressed by 1941 and 931 articles for surfaces and air respectively. Of these, 122 were performed in operating theatres. Since 1987 works have been published on spacecraft and since 2000, on the use of UVGI robots for disinfect air and surfaces. Conclusions Our study shows the studies on UVGI and related issues. It also shows most recently perspectives about the applications e.g. during prolonged human-crewed missions on spacecrafts, to inactivate microorganisms in environments where the exchange of air is impossible.

Virological surveillance of SARS-CoV-2 in an Italian Northern area: differences in gender, age and Real Time RT PCR cycle threshold (Ct) values in three epidemic periods.

BACKGROUND AND AIM OF THE WORK: Coronavirus Disease 2019 (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is a global public health emergency. The aim of this study was to investigate cases characteristics and Real Time RT PCR cycle threshold (Ct) values distribution of COVID-19 in an Italian Northern area during three periods: first period, February-May 2020; second period, June-August 2020; third period, September 2020-February 2021. METHODS: Real Time RT PCR was used to detect SARS-CoV-2 in respiratory samples (oro/nasopharyngeal swabs). RESULTS: A total of 254,744 samples were tested during the study period. Out of 20,188 positive samples (7.92%), 10,303 were females (51.04%) and 9,885 were males (48.96%). The percentage of positivity varied during the three different periods: 14.1% in the first period, 1.4% in the second and 9.2% in the third. The lowest Ct values were observed in the first phase of pandemic, with an overall average of 25.64. Overall average of the Ct values was lower in males than in females, 26.29 ± 6.04 and 26.84 ± 5.99 respectively. The oldest patients recorded lower Ct values. CONCLUSIONS: The findings of our study represent further evidence in support of the fact that male sex and older age showed lower Ct values, which means higher viral loads and higher infectious potential. These knowledges are useful to better understand the epidemiological aspects of COVID-19 and to perform effective Public Health Policies.

Virological surveillance of SARS-CoV-2 in an Italian northern area: comparison of Real Time RT PCR cycle threshold (Ct) values in three epidemic periods.

Aim of the study was to investigate the differences in Ct values in nasopharingeal swabs collected in three SARS-CoV-2 epidemic periods: first one from February 23 to March 25 (14 days from lockdown started on March 11); the second one from  March  26 to May 18 (14 days  from the end of strict lockdown on May 4) and the third one from May 19 until June 15. Viral RNA was detected in nasopharyngeal swabs obtained both from inpatients and outpatients. COVID-19 infection was confirmed according to the Ct values for N1 and N2 genes ascertained by Real-Time RT-PCR assay as described by the CDC. We calculated the prevalence of nasopharyngeal swabs tested positive for SARS-CoV-2, the mean and median of the Cts and the percentage of samples equal or below the Ct value of 25 in the 3 periods considered. The average value of Ct increased, going from 24.80 in the first epidemic period to 26.64 in the second period to 28.50 in the third period (p <0.001). The percentage of samples with Ct lower than or equal to 25 also decreased sharply from 54.7% to 20.0%. These findings need to be integrated with epidemiological and clinical data.

Influenza vaccine effectiveness in children: a retrospective study on eight post-pandemic seasons with trivalent inactivated vaccine.

BACKGROUND AND AIM OF THE WORK: The global burden of disease attributable to seasonal influenza virus in children is difficult to quantify. Children with chronic medical conditions and healthy children may experience severe or fatal complications. Aim of the study was to estimate the influenza vaccine effectiveness (VE) in a cohort of outpatient children. METHODS: From 2010 to 2018, a Pediatrician of Parma from the InfluNet network of Emilia-Romagna Region, performed nasal/throat swabs on every child with Influenza-like illness at least 14 days from the vaccination with trivalent vaccine. VE estimates against influenza season, virus type and subtype and age group were evaluated using a test-negative design. RESULTS: 2,480 swabs were performed. The 57.6% of the analyzed swabs were positive for influenza viruses. Type A (57%) and type B viruses (43%) co-circulated. The 37.1% of type A viruses belonged to subtype A(H3N2), 19.4% to subtype A(H1N1)pdm09. The subtype A(H3N2) was prevalent among children up to 23 months (42.4%) while the type B in the 2-4 (40.7%) and 5-16 year old age groups (49.4%). Overall, 19.9% of the children were vaccinated. The highest prevalence of vaccinated subjects was found in children aged 5-16 (30.5%). The VE against subtype A(H1N1)pdm09 was 63% (95%CI 42.6-76.0), against type B 27.5% (95%CI 7.9-42.9) and against subtype A(H3N2) -14.3%  (95%CI - 46.0-10.7). CONCLUSIONS: Our findings represent a useful contribution to the ongoing debate about the appropriateness of including influenza vaccination for healthy children, 6 months and older, in the updating National Vaccine Prevention Plan (PNPV).