Journal Article

The 2023 dengue outbreak in Lombardy, Italy: A one-health perspective

Zamboni, Giuditta, Farioli, Marco, Sammartino, Josè Camilla, Baldanti, Fausto, Arfani, Sara, Scardina, Giuditta, Delfanti, Fanny, Paolucci, Stefania, Cerutti, Lorenzo, Lilleri, Daniele, Barozzi, Manuela, Chiari, Mario, Regazzetti, Angelo, Paglia, Stefano, Brugnoli, Rita, Dafa, Anxhela, Bonini, Maira, Lelli, Davide, Sansebastian, Sheila, Carrera, Maya, Ferrari, Guglielmo, Maffeo, Manuel, Faccini, Marino, Piazza, Manuela, Cassaniti, Irene, Di Donato, Guido, Scovenna, Francesco, Poletti, Piero, Laini, Nunzia, Piralla, Antonio, Attanasi, Federica, Cereda, Danilo, Soresini, Marzia, Campanini, Giulia, Viscardi, Michela, Rossetti, Eva, Mele, Dalila, Romano, Greta, Negri, Antonella, Moreno, Ana, Molina Granè, Carla, Bergami, Federica, Ferrari, Alessandro, Sarasini, Antonella, Morani, Federica, Rovida, Francesca, Defilippo, Francesco, Tallarita, Enrico, Senatore, Sabrina, Lavazza, Antonio, Guglielmo Pitrolo, Antonino Maria, Vezzosi, Luigi, Marcacci, Maurilia, Bonalda, Francesca, Manica, Mattia, Tirani, Marcello, Merler, Stefano, Del Castillo, Gabriele, Parisi, Filippa, Furione, Milena, Ferrari, Piergiuseppe

2025

Overview

Here we reported the virological, entomological and epidemiological characteristics of the large autochthonous outbreak of dengue (DENV) occurred in a small village of the Lombardy region (Northern Italy) during summer 2023. After the diagnosis of the first autochthonous case on August 18, 2023, public health measures, including epidemiological investigation and vector control measures, were carried out. A serological screening for DENV antibodies detection was offered to the population. In the case of positive DENV IgM, a second sample was collected to detect DENV RNA and verify seroconversion. Entomological and epidemiological investigations were also performed. A modeling analysis was conducted to estimate the dengue generation time, transmission potential, distance of transmission, and assess diagnostic delays. Overall, 416 subjects participated to the screening program and 20 were identified as DENV-1 cases (15 confirmed and 5 probable). In addition, DENV-1 infection was diagnosed in 24 symptomatic subjects referred to the local Emergency Room Department for suggestive symptoms and 1 case was identified through blood donation screening. The average generation time was estimated to be 18.3 days (95 % CI: 13.1–23.5 days). R0 was estimated at 1.31 (95 % CI: 0.76–1.98); 90 % of transmission occurred within 500m. Entomological investigations performed in 46 pools of mosquitoes revealed the presence of only one positive pool for DENV-1. This report highlights the importance of synergic surveillance, including virological, entomological and public health measures to control the spread of arboviral infections.

• Publisher: Elsevier Ltd,Elsevier Limited,Elsevier
• Subject: Adolescent / Adult / Aedes - virology / Aged / Animals / Antibodies, Viral - blood / Aquatic insects / Child / Dengue - epidemiology / Dengue - prevention & control / Dengue - transmission / Dengue fever / Dengue Virus - immunology / Dengue Virus - isolation & purification / DENV-1 autochthonous outbreak / Disease Outbreaks / Disease prevention / Disease transmission / Emergency medical services / Epidemics / Epidemiology / Female / Human diseases / Humans / Humidity / Infections / Infectious Disease / Infectious diseases / Italy - epidemiology / Male / Middle Aged / Mosquito Vectors - virology / Mosquitoes / One Health / Outbreaks / Public health / Screening / Serology / Vector-borne diseases / Young Adult