Epidemiologia delle malattie infettive

 

Antibody responses to BNT162b2 SARS-CoV-2 mRNA vaccine among healthcare workers and residents of long-term care facilities: A cohort study in Northern Italy. Costanza Vicentini, Carla Maria Zotti, Alessandro Roberto Cornio, Jacopo Garlasco, Noemi Marengo, Davide Meddis, Savina Ditommaso, Monica Giacomuzzi, Gabriele Memoli, Valerio Bordino, Maria Michela Gianino, the Collaborating Group. Health Science Reports, February 2023.

Long-term care facilities (LTCFs) have been severely impacted by COVID-19, with a disproportionate amount of SARS-CoV-2 infections and related deaths occurring among residents. This study is part of an ongoing multicenter, prospective cohort study conducted among healthcare workers (HCWs) and residents of 13 LTCFs in Northern Italy designed to evaluate SARS-CoV-2 specific immunoglobulin class G (IgG) titers before and following vaccination with Pfizer/BNT162b2 SARS-CoV-2 mRNA vaccine (two doses of vaccine, 21 days apart). Serum samples were obtained from participants (t0) before vaccination, and (t1) 2 weeks after and analyzed to determine anti-S1 IgG antibodies. Five hundred and thirty-four participants were enrolled (404 subjects participated in both blood draws). Seropositivity was 50.19% at t0 and 99% at t1, with a significant difference in IgG titers. A higher proportion of residents were seropositive at t0 compared with HCWs, with significantly higher IgG titers among residents at both t0 and t1. Pre-existing immunity also had a significant effect on postvaccination IgG titers. However, a significant difference in titers at t1 between HCWs and residents considering only participants seropositive at t0 was found, with higher median titers among previously seropositive residents. Findings of this study provide scientific evidence endorsing the policy of universal vaccination in LTCFs.

 

Serological Responses up to 9 Months following COVID-19 mRNA Vaccination in Residents and Health-Care Workers of Long-Term Care Facilities: A Multicenter Prospective Cohort Study in Northern Italy. Costanza Vicentini, Carla Maria Zotti, Alessandro Roberto Cornio, Jacopo Garlasco, Noemi Marengo, Davide Meddis , Savina Ditommaso, Monica Giacomuzzi, Gabriele Memoli, Valerio Bordino, Maria Michela Gianino and on behalf of the Collaborating Group. Vaccines 2022, 10(12), 2183;

Long-term care facilities (LTCFs) were severely affected by COVID-19, in particular in Northern Italy. We aimed to assess antibody responses among residents and healthcare workers (HCWs) of 13 LTCFs through serum samples collected at three time points: prior to, two weeks, and 9 months after receiving Pfizer/BNT162b2 SARS-CoV-2 mRNA vaccine (respectively t0, t1, and t2). IgG antibodies targeted towards the S1 domain of the spike protein were measured, and results were expressed in binding antibody units (BAU/mL). Friedman’s average rank test was performed to compare antibody titres between the three time points. Two logistic regression models were built to identify independent predictors of (1) developing and (2) maintaining a significant antibody response to vaccination, using a previously identified threshold. In total, 534 subjects were enrolled (371 HCWs and 163 residents). The antibody titres at t1 were the highest; at t2, the IgG titres significantly decreased, remaining however 10 times higher compared to titres at t0. Previous infection was the only significant predictor of developing and maintaining a response over threshold in both models. Results of this study provided further insights on the humoral response elicited by vaccination, and on host factors determining variations in its magnitude and kinetics.

 

Seroprevalence of infection-induced SARS-CoV-2 antibodies among healthcare users of Northern Italy – results from two serosurveys (October-November 2019 – September-October 2021). Costanza Vicentini, Valerio Bordino, Alessandro Roberto Cornio, Davide Meddis, Noemi Marengo, Savina Ditommaso, Monica Giacomuzzi, Gabriele Memoli, Gabriella Furfaro, Giulio Mengozzi, Valentina Ricucci, Giancarlo Icardi, Carla Maria Zotti. Journal of Infectious Diseases (2022).

Objective: To estimate the seroprevalence of SARS-CoV-2 in autumn 2019 (before case zero was identified in Italy) and 2021 among residual sera samples of healthcare users of Piedmont, Northwestern Italy.

Methods: Two serosurveys were conducted. Samples were tested for the detection of IgG antibodies against the S1 domain of the spike protein, using a semi-quantitative method. Positive samples from the 2019 survey were independently re-tested using a multiplex panel for the detection of IgG antibodies against the receptor-binding domain, S1 and S2, and nucleocapsid (N). Positive samples from the 2021 survey underwent repeat testing with ELISA for the detection of IgG anti-N antibodies. Prevalence rates according to gender and age groups, together with their respective 95% CIs, were calculated.

Results: Overall, the proportion of positive samples was 2/353 in 2019 and 22/363 in 2021, with an estimated seroprevalence of 0.27% (95% CI 0 – 1.86) and 6.21% (95% CI 3.9 – 9.31), in 2019 and 2021 respectively.

Conclusion: Results of this study support the hypothesis that the virus was circulating in Italy as early as autumn 2019. The role of these early cases in broader transmission dynamics remains to be determined.

 

A cross-sectional study of SARS-CoV-2 seropositivity among healthcare workers and residents of long-term facilities in Italy, January 2021. Valerio Bordino, Noemi Marengo, Jacopo Garlasco, Alessandro Roberto Cornio, Davide Meddis, Savina Ditommaso, Monica Giacomuzzi, Gabriele Memoli, Maria Michela Gianino, Costanza Vicentini, Carla Maria Zott, Collaborating group.J Med Virol. 2022 Jul;94(7):3054-3062.

Long-term care facilities (LTCFs) are high-risk settings for SARS-CoV-2 infection. This study aimed to describe SARS-CoV-2 seropositivity among residents of LTCFs and health-care workers (HCWs). Subjects were recruited in January 2021 among unvaccinated HCWs of LTCFs and hospitals and residents of LTCFs in Northern Italy. Information concerning previous SARS-CoV-2 infections and a sample of peripheral blood were collected. Anti-S SARS-CoV-2 IgG antibodies were measured using the EUROIMMUN Anti-SARS-CoV-2 QuantiVac ELISA kit (EUROIMMUN Medizinische Labordiagnostika AG). For subjects with previous COVID-19 infection, gender, age, type of subject (HCW or resident), and time between last positive swab and blood draw were considered as possible determinants of two outcomes: the probability to obtain a positive serological result and antibody titer. Six hundred and fifty-eight subjects were enrolled. 56.1% of all subjects and 65% of residents presented positive results (overall median antibody titer: 31.0 RU/ml). Multivariable models identified a statistically significant 4% decrease in the estimated antibody level for each 30-day increase from the last positive swab. HCWs were associated with significant odds for seroreversion over time (OR: 0.926 for every 30 days, 95% CI: 0.860-0.998), contrary to residents (OR: 1.059, 95% CI: 0.919-1.22). Age and gender were not factors predicting seropositivity over time. Residents could have a higher probability of maintaining a seropositive status over time compared to HCWs.

 

Does ABO blood group influence antibody response to SARS-CoV-2 vaccination? Costanza Vicentini, Valerio Bordino, Alessandro Roberto Cornio, Davide Meddis, Savina Ditommaso, Monica Giacomuzzi, Gabriele Memoli, Fabrizio Bert, Carla Maria Zotti. Vox Sang. 2022 May;117(5):754-755.

Abstract non disponibile

 

Pertussis immunisation during pregnancy: Antibody levels and the impact of booster vaccine. Jacopo Garlasco, Valerio Bordino, Noemi Marengo, Erika Rainero, Alessandro Scacchi, Savina Ditommaso, Monica Giacomuzzi, Fabrizio Bert, Carla Maria Zotti.Vaccine. 2021 Aug 16;39(35):4957-4963.

Pertussis (whooping cough) is a highly infectious disease caused by Bordetella pertussis. Mothers lacking adequate immunity and contracting the disease represent the biggest risk of transmission to new-borns, for which the disease is often a threat. The aim of the study was to estimate the frequency of pertussis susceptibility among pregnant women, in order to point out the need for a vaccine recall during pregnancy, and to evaluate the antibody response in already vaccinated women. A cross-sectional observational study was conducted in the blood test centre of "St. Anna" Obstetrics and Gynaecology Hospital in Turin (Piedmont, Italy). Eligibility criteria included pregnant women coming to the centre for any blood test, aged 18 or above and with gestational age between 33 and 37 weeks at the moment of the blood draw. The data collection was carried out from May 2019 to January 2020 and the concentration of anti-Pertussis Toxin (anti-PT) IgG was measured through the Enzyme-Linked Immunosorbent Assay (ELISA) technique. Two-hundred women (median age 35) were enrolled: 132 (66%) had received at least one dose of pertussis vaccine, 82 of which during pregnancy. Recently vaccinated women had significantly higher antibody titres (even 12-15 times as high) compared to those vaccinated more than 5 years before or never vaccinated at all (p < 0.0001). Moreover, 95.1% of recently vaccinated women had anti-PT IgG levels above 10 IU/ml, and 85.4% above 20 IU/ml, while the same proportions were as low as 37% and 21% (respectively) in the group of women not vaccinated in pregnancy. This study confirmed that the vaccination is greatly effective in ensuring high antibody titres in the first months after the booster vaccine, with considerable differences in anti-PT IgG compared to women vaccinated earlier or never vaccinated at all, and therefore vaccinating pregnant women against pertussis still represents a valuable strategy.

 

Antibody detection and cross-reactivity among species and serogroups of Legionella by indirect immunofluorescence test. S. Ditommaso, M. Giacomuzzi, M. Gentile, C. M. Zotti. J Microbiol Methods. 2008 Oct;75(2):350-3

The purpose of the present study was to determine possible cross-reactivity between different serogroups or between different species by means of bacterial smears of individual L. pneumophila serogroups and several non-pneumophila Legionella spp. Using BIOCHIP slide we found a considerable frequency of cross-reactions with L. pneumophila serogroup 12 (88.4%) therefore BIOCHIP slide proved as useful method for identification of cross-reactivity between members of the Legionnellaceae.

 

Prevalence of anti-legionella antibodies among Italian hospital workers. P Borella, A Bargellini, I Marchesi, S Rovesti, G Stancanelli, S Scaltriti, M Moro, M T Montagna, D Tatò, C Napoli, M Triassi, S Montegrosso, F Pennino, C M Zotti, S Ditommaso, M Giacomuzzi. J Hosp Infect. 2008 Jun;69(2):148-55.

This study evaluated the prevalence of anti-legionella antibodies in workers at hospitals with a long-term history of legionella contamination. The hospitals are located in Milan and Turin, northern Italy, and in Naples and Bari, southern Italy. Antibody prevalence and titres of healthcare workers, medical and dental students and blood donors were assessed. In total 28.5% of subjects were antibody positive, most frequently to L. pneumophila serogroups 7-14. Major differences were observed in seroprevalence and type of legionella antibody in persons from different geographic areas. Healthcare workers had a significantly higher frequency of antibodies compared with blood donors in Milan (35.4 vs 15.9%, P<0.001), whereas in Naples both groups exhibited high antibody frequency (48.8 vs 44.0%) and had a higher proportion of antibodies to legionella serogroups 1-6. Dental workers had a higher seroprevalence than office staff in Bari, but not in Turin, where daily disinfecting procedures had been adopted to avoid contamination of dental unit water. No association was found between the presence of antibodies and the presence of risk factors for legionellosis, nor with the occurrence of pneumonia and/or flu-like symptoms. In conclusion, the presence of legionella antibodies may be associated with occupational exposure in the hospital environment, but there was no evidence of any association with disease.

 

Legionella colonization of the respiratory tract in patients without nosocomial exposure. Savina Ditommaso, Monica Giacomuzzi, Marino Gentile, Angela Ruggenini Moiraghi, Roberto Arione, Sergio Baldi, Paolo Solidoro, Adriano Ceccarelli, Carla M Zotti. Infect Control Hosp Epidemiol. 2008 May;29(5):470-1.

Abstract non disponibile

 

Incidence of legionellosis in hospitals contaminated by Legionella pneumophila other than serogroup 1. S Ditommaso, M Giacomuzzi, C Biasin, M Gentile, G Maggiorotto, A Ruggenini Moiraghi, C M Zotti, Legionellosis Collaborating Group. Infect Control Hosp Epidemiol. 2007 Apr;28(4):509-11.

Abstact non disponibile

 

Colonization of a water system by Legionella organisms and nosocomial legionellosis: a 5-year report from a large Italian hospital. S Ditommaso, C Biasin, M Giacomuzzi, C M Zotti, R Arione, E Guglielmi, S Barbaro, A Di Leo, R Serra, G Marchiaro, A Ruggenini Moiraghi. Infect Control Hosp Epidemiol. 2006 May;27(5):532-5.

Abstract non disponibile

 

Legionella pneumophila in a hospital in Torino, Italy. A retrospective one-year study. A Moiraghi Ruggenini, M Castellani Pastoris, P J Dennis, C Barral, A Sciacovelli, F Carle, M Bolgiani, G Passarino, M G Mingrone, C Passi, et al. Epidemiol Infect. 1989 Feb;102(1):21-9.

Legionella pneumophila serogroup 1 was isolated from post mortem specimens from 13 out of 58 patients with pneumonia diagnosed at autopsy. The results of a study undertaken in the hospital environment showed that the water plumbing system was colonized with L. pneumophila serogroup 1 which could also be isolated from respiratory devices filled with tap water. Control measures instituted are described.

 

Nosocomial legionellosis associated with use of oxygen bubble humidifiers and underwater chest drains. A Moiraghi, M Castellani Pastoris, C Barral, F Carle, A Sciacovelli, G Passarino, P Marforio. J Hosp Infect. 1987 Jul;10(1):47-50.

In 1 year 12 of 48 patients who developed fatal pneumonia following admission with non-respiratory disorders to the Hospital Molinette, Torino, yielded Legionella pneumophila serogroup 1 from lung at autopsy. Patients were hospitalized on seven different wards for different conditions; only two of the wards had air conditioning but legionellas were not isolated from these. All patients were in poor health or immunocompromised. Some patients had inhaled humidified oxygen from piped supplies and three had undergone surgery. Legionella pneumophila serogroup 1 was detected in the water of oxygen bubble humidifiers and an underwater chest drain. The contaminated devices had been filled with tap or distilled water and the hospital water supply was found to be contaminated with L. pneumophila serogroup 1. Our findings suggest that filling bubble humidifiers or underwater chest drains with tap water is a potential hazard and should be avoided.