Epidemiology of West Nile Virus Infections in Humans, Italy, 2012–2020: A Summary of Available Evidences
In Italy, human cases of West Nile virus (WNV) infection have been recorded since 2008, and seasonal outbreaks have occurred almost annually. In this study, we summarize available evidences on the epidemiology of WNV and West Nile neuro-invasive disease (WNND) in humans reported between 2012 and 202...
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MDPI AG
2021-04-01
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| Series: | Tropical Medicine and Infectious Disease |
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| Online Access: | https://www.mdpi.com/2414-6366/6/2/61 |
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| author | Matteo Riccò Simona Peruzzi Federica Balzarini |
| author_facet | Matteo Riccò Simona Peruzzi Federica Balzarini |
| author_sort | Matteo Riccò |
| collection | DOAJ |
| description | In Italy, human cases of West Nile virus (WNV) infection have been recorded since 2008, and seasonal outbreaks have occurred almost annually. In this study, we summarize available evidences on the epidemiology of WNV and West Nile neuro-invasive disease (WNND) in humans reported between 2012 and 2020. In total, 1145 WNV infection cases were diagnosed; of them 487 (42.5%) had WNND. A significant circulation of the pathogen was suggested by studies on blood donors, with annual incidence rates ranging from 1.353 (95% confidence intervals (95% CI) 0.279–3.953) to 19.069 cases per 100,000 specimens (95% CI 13.494–26.174). The annual incidence rates of WNND increased during the study period from 0.047 cases per 100,000 (95% CI 0.031–0.068) in 2012, to 0.074 cases per 100,000 (95% CI 0.054–0.099) in 2020, peaking to 0.377 cases per 100,000 (95% CI 0.330–0.429) in 2018. There were 60 deaths. Cases of WNND were clustered in Northern Italy, particularly in the Po River Valley, during the months of August (56.7%) and September (27.5%). Higher risk for WNND was reported in subjects of male sex (risk ratio (RR) 1.545, 95% CI 1.392–1.673 compared to females), and in older age groups (RR 24.46, 95% CI 15.61–38.32 for 65–74 y.o.; RR 43.7, 95% CI 28.33–67.41 for subjects older than 75 years), while main effectors were identified in average air temperatures (incidence rate ratio (IRR) 1.3219, 95% CI 1.0053–1.7383), population density (IRR 1.0004, 95% CI 1.0001–1.0008), and occurrence of cases in the nearby provinces (IRR 1.0442, 95% CI 1.0340–1.0545). In summary, an enhanced surveillance is vital for the early detection of human cases and the prompt implementation of response measures. |
| first_indexed | 2024-03-10T11:59:51Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2414-6366 |
| language | English |
| last_indexed | 2024-03-10T11:59:51Z |
| publishDate | 2021-04-01 |
| publisher | MDPI AG |
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| series | Tropical Medicine and Infectious Disease |
| spelling | doaj.art-60c394e3a7054cfd8ed7731a51b7994f2023-11-21T17:01:27ZengMDPI AGTropical Medicine and Infectious Disease2414-63662021-04-01626110.3390/tropicalmed6020061Epidemiology of West Nile Virus Infections in Humans, Italy, 2012–2020: A Summary of Available EvidencesMatteo Riccò0Simona Peruzzi1Federica Balzarini2Servizio di Prevenzione e Sicurezza Negli Ambienti di Lavoro (SPSAL), AUSL-IRCCS di Reggio Emilia, Via Amendola n.2, I-42122 Reggio Emilia, RE, ItalyLaboratorio Analisi Chimico Cliniche e Microbiologiche, Ospedale Civile di Guastalla, AUSL-IRCCS di Reggio Emilia, I-42016 Guastalla, RE, ItalyDipartimento P.A.A.P.S.S., Servizio Autorizzazione e Accreditamento, Agenzia di Tutela della Salute (ATS) di Bergamo, Via Galliccioli, 4, I-24121 Bergamo, BG, ItalyIn Italy, human cases of West Nile virus (WNV) infection have been recorded since 2008, and seasonal outbreaks have occurred almost annually. In this study, we summarize available evidences on the epidemiology of WNV and West Nile neuro-invasive disease (WNND) in humans reported between 2012 and 2020. In total, 1145 WNV infection cases were diagnosed; of them 487 (42.5%) had WNND. A significant circulation of the pathogen was suggested by studies on blood donors, with annual incidence rates ranging from 1.353 (95% confidence intervals (95% CI) 0.279–3.953) to 19.069 cases per 100,000 specimens (95% CI 13.494–26.174). The annual incidence rates of WNND increased during the study period from 0.047 cases per 100,000 (95% CI 0.031–0.068) in 2012, to 0.074 cases per 100,000 (95% CI 0.054–0.099) in 2020, peaking to 0.377 cases per 100,000 (95% CI 0.330–0.429) in 2018. There were 60 deaths. Cases of WNND were clustered in Northern Italy, particularly in the Po River Valley, during the months of August (56.7%) and September (27.5%). Higher risk for WNND was reported in subjects of male sex (risk ratio (RR) 1.545, 95% CI 1.392–1.673 compared to females), and in older age groups (RR 24.46, 95% CI 15.61–38.32 for 65–74 y.o.; RR 43.7, 95% CI 28.33–67.41 for subjects older than 75 years), while main effectors were identified in average air temperatures (incidence rate ratio (IRR) 1.3219, 95% CI 1.0053–1.7383), population density (IRR 1.0004, 95% CI 1.0001–1.0008), and occurrence of cases in the nearby provinces (IRR 1.0442, 95% CI 1.0340–1.0545). In summary, an enhanced surveillance is vital for the early detection of human cases and the prompt implementation of response measures.https://www.mdpi.com/2414-6366/6/2/61spatiotemporal patternWest Nile neuro-invasive diseaseWest Nile Virus |
| spellingShingle | Matteo Riccò Simona Peruzzi Federica Balzarini Epidemiology of West Nile Virus Infections in Humans, Italy, 2012–2020: A Summary of Available Evidences Tropical Medicine and Infectious Disease spatiotemporal pattern West Nile neuro-invasive disease West Nile Virus |
| title | Epidemiology of West Nile Virus Infections in Humans, Italy, 2012–2020: A Summary of Available Evidences |
| title_full | Epidemiology of West Nile Virus Infections in Humans, Italy, 2012–2020: A Summary of Available Evidences |
| title_fullStr | Epidemiology of West Nile Virus Infections in Humans, Italy, 2012–2020: A Summary of Available Evidences |
| title_full_unstemmed | Epidemiology of West Nile Virus Infections in Humans, Italy, 2012–2020: A Summary of Available Evidences |
| title_short | Epidemiology of West Nile Virus Infections in Humans, Italy, 2012–2020: A Summary of Available Evidences |
| title_sort | epidemiology of west nile virus infections in humans italy 2012 2020 a summary of available evidences |
| topic | spatiotemporal pattern West Nile neuro-invasive disease West Nile Virus |
| url | https://www.mdpi.com/2414-6366/6/2/61 |
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