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).

Immunity status against tetanus in young migrants: a seroprevalence study.

BACKGROUND AND AIM OF THE WORK: Thanks to the highly effective vaccine, tetanus became sporadic in high-income countries with well-established primary childhood immunization programs, but it is common in low-income countries. The migrants, leaving countries with poor immunization programs or where vaccinations have been interrupted, may represent a new risk group for tetanus in host countries. A seroprevalence study was conducted to estimate the immunological status against tetanus in young migrants without vaccination documentation. METHODS: After a careful assessment by vaccination services of the Local Health Authority, all migrants recently arrived in Italy were included in the serosurvey. Titers of anti-tetanus toxoid were measured using a commercial ELISA kit. Subjects were stratified by age and by WHO region. Antibody titers <0.10 IU/ml were considered to be seronegative, between 0.10 and 1.00 IU/ml as intermediate protection, and >1.00 IU/ml high protection. RESULTS: From January 2004 to December 2019, 2,326 blood samples were collected. Mean age was 13.9 years with no differences between WHO regions. The percentage of the subjects without protective antibodies was 22.3%, with an intermediate level was 45.2%, with high titer was 32.5%. Among migrant coming from African and Eastern Mediterranean WHO regions, the highest percentages of seronegative titers and, at the same time, the low percentages of high protective levels were found. Titers decreased with age. CONCLUSIONS: The significant proportion of seronegative migrants and the decrease of protective titers increasing age, confirm the importance of the evaluation of the immunological status to employ the appropriate vaccination strategy.

Passive air sampling: the use of the index of microbial air contamination.

BACKGROUND: Bioaerosol plays an important role in human life with potentially infectious, allergic and toxic effects. Active and passive methods can be used to assess microbial air contamination, but so far there is not a unanimous consensus regarding the indications about methods to be used and how to interpret the results. The passive method has been standardized by the Index of Microbial Air contamination (IMA). Classes of contamination and maximum acceptable levels of IMA have been proposed, related to different infection or contamination risks. The aim of this study was to provide information about the use of the passive sampling method, with reference to the IMA standard. METHODS: We searched PubMed and Scopus for articles published until January 2020 reporting the citation of the article by Pasquarella et al. "The index of microbial air contamination. J Hosp Infect 2000". Only studies in English language where the IMA standard was applied were considered. Studies regarding healthcare settings were excluded. RESULTS: 27 studies were analyzed; 12 were performed in Europe, 8 in Asia, 5 in Africa, 2 in America. Cultural heritage sites, educational buildings and food industries were the most common indoor monitored environments; in 8 studies outdoor air was monitored. CONCLUSIONS: This review has provided a picture of the application of standard IMA in different geographic areas and different environments at risk of airborne infection/contamination. The analysis of the results obtained, together with a wider collection of data, will provide a useful contribution towards the definition of reference limits for the various types of environments to implement targeted preventive measures.

[Fungal contamination in a University building].

BACKGROUND: It is recognized that airborne fungi can cause illnesses in humans but data on environmental exposure are still poor. The aim of this study was to evaluate the fungal airborne contamination in a university building. METHODS: The study was performed in February and May 2018; air samples were collected, before activity (on Monday) and during activity, (on Friday), both through active (CFU/m3) and passive (Index of microbial air contamination, IMA) method. Fungi were identified by using the scotch test. RESULTS: In February the median fungal contamination value decreased from 14 CFU/m3 before activity to 7 CFU/m3 during activity, while IMA median remains 0. Instead in May both increased during activity (from 87 to 140 CFU/m3; from 5.5 to 7.5 IMA). Overall values increased in May compared to February. Aspergillus spp., Penicillium spp.,  Cladosporium spp. Absidia spp. were the genera most frequently isolated in both months, while in May Chaetomium spp. e Ulocladium spp. were recovered too. CONCLUSIONS: Seasonal trend in the levels of fungal contamination of the air was observed, with a statistically significant increase in May. This study represents the first step of a wider study aimed at enhancing knowledge about air fungal contamination.

On field vaccine effectiveness in three periods of 2018/2019 influenza season in Emilia-Romagna Region.

BACKGROUND AND AIM OF THE WORK: Epidemic influenza is associated with significant morbidity and mortality, particularly in people at risk. The vaccine reduces complications, hospitalization and mortality excess, as well as health care and social costs. Aim of the study was to estimate the influenza vaccine effectiveness (VE) in Emilia-Romagna Region during the 2018/2019 season. METHODS: Within the context of virological surveillance conducted at the Regional Reference Laboratory of Parma, nasal/throat swabs were performed by sentinel practitioners and clinicians, on patients with ILI (Influenza-like illness). VE estimates, overall and against subtype A(H1N1)pdm09 and A(H3N2), were evaluated in three periods of the season, using a test-negative case-control design. RESULTS: From November 2018 to April 2019, 2,230 specimens were analyzed: 1,674 (75.1%) performed by clinicians and 556 (24.9%) by sentinel practitioners of the regional network. The season was characterized by the predominant circulation of influenza type A viruses: 57.4% belonged to subtype A(H3N2), 41.2% to subtype A(H1N1)pdm09. 23.5% of patients was vaccinated against influenza with quadrivalent or adjuvate vaccine. The overall VE was -5% (95% CI -33% - 18%) with a decreasing trend during the season. The overall VE against subtype A(H1N1)pdm09 was 39% (95% CI 11% - 58%) and remained stable during the season. The overall VE against subtype A(H3N2) was -43% (95% CI -89% - -9%), and showed an important decreasing trend. CONCLUSIONS: The possibility to make accurate and continuous VE estimates during the season will help to better define the composition of the vaccine for the following season.

Immunity status against poliomyelitis in young migrants: a seroprevalence study.

BACKGROUND AND AIM OF THE WORK: Recent seroprevalence studies in different population groups have shown low antibody titers against poliomyelitis, especially in young adults. This, together with the reduction of vaccination rates, could favor the reintroduction of poliovirus in long-time polio-free countries. Within the Surveillance system of acute flaccid paralysis, a prevalence study was conducted to estimate the immunological status associated with poliomyelitis in young migrants. METHODS: Local Health Authority collected serum samples in young migrants, without vaccination documentation. Antibodies levels were assessed with a long incubation neutralization assay. Subjects were stratified by age and by WHO region. Seroprotection was defined by a titer equal or above 1:8 and titers > 1:2 were log-transformed and evaluated as geometric mean titers (GMTs). RESULTS: From January 2004 to August 2017, 1138 blood samples were collected. Mean age was 13.3 years with no differences between WHO regions. The percentage of antibody titers below 1:8 was 6.0% versus poliovirus 1 (PV1), 7.7% versus poliovirus 2 (PV2) and 15% versus poliovirus 3 (PV3). The GMTs were 45.5, 29.5 and 20 towards PV1, PV2 and PV3 respectively. In each WHO region, the GMTs towards PV3 were consistently the lowest, and the Europeans showed the lowest GMTs both towards PV2 and PV3 (27.5 and 15.3 respectively). GMTs decreased with age. CONCLUSION: The low GMTs and the clear tendency to decrease with increasing age of the subjects, especially against to PV1, confirm the framework of attention that polio is receiving at national and international level.

Virological Surveillance of Influenza in the eight epidemic seasons after the 2009 pandemic in Emilia-Romagna (Northern Italy).

BACKGROUND AND AIM OF THE WORK: Influenza virological surveillance is essential for monitoring the evolution of influenza viruses (IVs) as well as for annual updating of the vaccine composition. The aim of this study is to analyse IVs circulation in Emilia-Romagna during the eight epidemic seasons after the 2009 pandemic and to evaluate their match with seasonal vaccine strains. METHODS: A total of 7882 respiratory specimens from patients with influenza-like illness (ILI), were collected by regional sentinel practitioners and hospital physicians. Viral investigations were conducted by rRT-PCR assay. Genetic characterization was performed for a spatial-temporal representative number of influenza laboratory-confirmed specimens. RESULTS: Influenza-positive samples per season ranged between 28.9% (2013-2014) and 66.8% (2012-2013). Co-circulation of IVs type A and type B was observed in all seasons, although with a different intensity. In all seasons, the highest number of positive samples was recorded in younger patients aged 5-14 years with relative frequencies ranging from 40% in the 2013-2014 season and 78% in the 2012-2013 season. Since the 2009 pandemic, A/H1N1pdm09 IVs circulating were closely related to the vaccine strain A/California/7/2009. Antigenic mismatch between vaccine strain and A/H3N2 IVs was observed in the 2011-2012 and 2014-2015 seasons. During 2015-2016, 2016-2017 and 2017-2018 seasons a complete or nearly complete mismatch between the predominant influenza B lineage of IVs type B circulating and vaccine B lineage occurred. CONCLUSIONS: This analysis confirms the importance of the virological surveillance and highlights the need of a continuous monitoring of IVs circulation, to improve the most appropriate vaccination strategies. (www.actabiomedica.it).

Poliovirus and non-polio-enterovirus environmental surveillance in Parma within the "Global Polio Eradication Program" (GPEI).

BACKGROUND: Environmental surveillance of poliovirus plays an essential role in GPEI both for the detection of WTP and VDPV circulation in endemic areas and for monitoring their absence in polio-free countries. METHODS: Since 2005 to 2018, in Parma, 642 wastewater samples were collected from the two wastewater treatment plants and analyzed according to the WHO Guidelines. All isolates supposed being poliovirus were sent to ISS reference laboratory for molecular characterization while NPEV only refer to samples up to 2016. RESULTS: Positivity was obtained in 68% of samples without significant difference between the two treatment plants. Six polioviruses (1.4%) were detected, all characterized as Sabin-like: 4 of them (66.7%) were type 3 and 2 (33.3%) type 1. Coxsackieviruses B mainly recurred among NPEV (85%) while residual 15% was Echoviruses. B4 was the most frequent Coxsackie serotype isolated (31%) while, among Echovirus, Echo 7 and Echo 11 prevail (both 23%). CONCLUSION: As OPV isn't used in Italy since 2002, recovery of Sabin-like polioviruses indicates the possibility of poliovirus reintroduction, considering also the important exposure to migratory flows. Finally, monitoring the environmental circulation of NPEV, could compensate for the lack of a surveillance system of the infections they cause.

Vaccination status and prevalence of enteric viruses in internationally adopted children. The case of Parma, Italy.

On age basis, internationally adopted children may have begun or fully completed all required vaccinations, but official documentation from original Countries is frequently insufficient. Aims of this study were to evaluate the seroprotection rate for tuberculosis, hepatitis B, poliomyelitis and tetanus according to immunization cards in 67 children recently adopted and to test the prevalence of enterovirus on faecal specimens. Seroprotection and vaccination status were frequently inconsistent and these results confirm that immunitary surveillance is a cornerstone for the prevention of diseases for which a vaccination is available. (www.actabiomedica.it).

Legionella contamination in the water system of hospital dental settings.

BACKGROUND AND AIM OF THE WORK: Among hospital facilities the dental unit is an environment that is at major risk of Legionella due to equipment such as the air/water syringe, the turbine, the micromotor and the scaler which generate potentially harmful aerosols that may to be a source of exposure to Legionella spp. particularly in immunodeficient patients, and those affected by chronic diseases, and also in dental personnel. Therefore, an examination of the extent of Legionella spp. contamination in the dental chairs waterlines and the incoming water supply of some public dental units is the subject of the present study. METHODS: From February 2002 to March 2004, a total of 208 water samples were collected: 160 samples from the water supply of 4 dental chair and 48 samples from the cold incoming tap water of 2 units. RESULTS: Legionella spp. was detected in 46 samples (22.1% ): 19 of them (41.3% of Legionella spp.; 9.1% of the total) were Legionella pneumophila; Pseudomonas aeruginosa was detected in 86 samples (41.4%) and both microorganisms were detected in 2 samples (0.96%). CONCLUSIONS: Our results show a microbiological condition in dental settings, that is not at all satisfactory due to the presence of Legionella in concentrations that are considered to be a health hazard (> or = 10(3)) in certain cases. Given the extent of the health risk in these surroundings, the difficulty in its assessment, and also considering the wide diffusion of general dental care, our investigation has confirmed the need to regularly monitor the microbiological condition of water in dental units.