Dynamics of viral DNA shedding and culture viral DNA positivity in different clinical samples collected during the 2022 mpox outbreak in Lombardy, Italy

• Published in: Travel Medicine and Infectious Disease
• Main Authors: Antonio Piralla, Davide Mileto, Alberto Rizzo, Guglielmo Ferrari, Federica Giardina, Stefano Gaiarsa, Greta Petazzoni, Micol Bianchi, Federica Salari, Fiorenza Bracchitta, Josè Camilla Sammartino, Alessandro Ferrari, Gloria Gagliardi, Alessandro Mancon, Claudio Fenizia, Mara Biasin, Francesca Rovida, Stefania Paolucci, Elena Percivalle, Alessandra Lombardi, Valeria Micheli, Silvia Nozza, Antonella Castagna, Davide Moschese, Spinello Antinori, Andrea Gori, Paolo Bonfanti, Roberto Rossotti, Antonella D'Arminio Monforte, Federica Attanasi, Marcello Tirani, Danilo Cereda, Fausto Baldanti, Maria Rita Gismondo, Miriam Cutrera, Marianna Cuomo, Federica De Poli, Giulia Campanini, Antonino Maria Guglielmo Pitrolo, Elizabeth Iskandar, Irene Cassaniti, Raffaele Bruno, Giuliano Rizzardini, Massimo Puoti, Francesco Castelli, Laura Corsico, Andrea Giacomelli, Giacomo Pozza, Giacomo Casalini, Angelo Raccagni, Bendetta Trentacapilli, Costanza Bertoni, Elena Bruzzesi, Caterina Candela, Daniele Tesoro, Giovanni Mule, Alessandra Bandera, Antonio Muscatello Bianca Mariani, Manuel Maffeo, Riccardo Vecchio, Sara Piccinelli
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2024
• Subjects: Mpox virus; Molecular epidemiology; Next generation sequencing; Re-Emerging virus; Multiple samples; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1016/j.tmaid.2024.102698; https://doaj.org/article/3f1b0a37603c408895b47779b1b11b32

Background: Mpox virus (MPXV) has recently spread outside of sub-Saharan Africa. This large multicentre study was conducted in Lombardy, the most densely populated Italian region accounting for more than 40% of Italian cases. The present study aims to: i) evaluate the presence and the shedding duration of MPXV DNA in different body compartments correlating the MPXV viability with the time to onset of symptoms; ii) provide evidence of MPXV persistence in different body compartment as a source of infection and iii) characterize the MPXV evolution by whole genome sequencing (WGS) during the outbreak occurred in Italy. Material and methods: The study included 353 patients with a laboratory-confirmed diagnosis of MPXV infection screened in several clinical specimens in the period May 24th - September 1st, 2022. Viral isolation was attempted from different biological matrices and complete genome sequencing was performed for 61 MPXV strains. Results: MPXV DNA detection was more frequent in the skin (94.4%) with the longest median time of viral clearance (16 days). The actively-replicating virus in cell culture was obtained for 123/377 (32.6%) samples with a significant higher viral quantity on isolation positive samples (20 vs 31, p < 0.001). The phylogenetic analysis highlighted the high genetic identity of the MPXV strains collected, both globally and within the Lombardy region. Conclusion: Skin lesion is gold standard material and the high viral load and the actively-replicating virus observed in genital sites confirms that sexual contact plays a key role in the viral transmission.