A comprehensive one-year correlation analysis between prevalence and number of sars-cov-2 rna copies detected in wastewater from 8 sicilian cities in italy
 
More details
Hide details
1
University of Palermo Department of Health Promotion, Mother and Child Care, Internal Medicine, and Medical Specialties "G. D'Alessandro" (PROMISE) Via del Vespro, 133, 90127 Palermo Italy
 
2
Istituto Zooprofilattico Sperimentale della Sicilia Area diagnostica virologica Via Gino Marinuzzi, 3, 90129 Palermo Italy
 
3
University Hospital "P. Giaccone." Clinical Epidemiology Unit and Regional Reference Laboratory of Western Sicily for the Emergence of COVID-19 Via del Vespro 133, 90127 Palermo Italy
 
 
Publication date: 2023-04-26
 
 
Popul. Med. 2023;5(Supplement):A1876
 
ABSTRACT
Background and objectives:
Several authors have reported positive correlations between wastewater SARS-CoV-2 concentrations and the community’s burden of infection, providing information about the disease’s epidemiological trend. This pre-post study evaluated – within a year of active surveillance, from October 1st,2021, to September 30th, 2022 – the relation between daily SARS-CoV-2 prevalence and the number of genome copies/L detected in West Sicily wastewater samples. This study is part of a national framework coordinated by Istituto Superiore di Sanità.

Methods:
Quantitative data from analysing 486 wastewater samples collected from 9 purification plants in 8 Sicilian cities (Agrigento, Bagheria, Caltanissetta, Enna, Marsala, Mazara del Vallo, Palermo, and Trapani) were obtained. Correlation and logistic regression analysis were performed between the communal-based aggregated prevalence of daily SARS-CoV-2 cases obtained from the integrated national surveillance system and the number of genomic copies/L derived from wastewater analysis for different times (day-prevalence t0, t7, t14) and different periods (0- to 6-, 6- to 12- and comprehensive 12 months).

Results:
A moderate-high correlation index was retrieved for 0- to 6- months (October 2021–March 2022, t0: r=0.75, R2=0.57; t7 r=0.76, R2=0.58, t14 r=0.76, R2=0.58) and overall analyses (October 2021–October 2022, t0 r=0.63, R2=0.40; t7 r=0.62, R2=0.38; t14 r=0.59, R2=0.35). On the other hand, 6- to 12- months analysis displayed a relevant decline in correlation (March 2022–October 2022, t0 r=0.19, R2=0.04; t7 r=0.17, R2=0.03, p=0.004; t14 r=0.11, R2=0.01). All data except t14 were statistically significant (p<0.0001).

Conclusions:
Significance results were displayed for 0- to 6- and overall analysis at 0,7 and 14 days. Despite 6- to 12- months samples tested positive for RNA copies, a progressive loss of significance was found probably mainly attributable to a progressive loss of function in prevalence estimation of the swab-related SARS-CoV-2 positivity detecting system due to underreporting of cases.

ISSN:2654-1459
Journals System - logo
Scroll to top