Letter to the editor: Atypical weather is associated with the 2022 early start of West Nile virus transmission in Italy

Global transmission suitability maps for dengue virus transmitted byAedes aegyptifrom 1981 to 2019

“…Given that DENV incidence data are available at the municipality level for Brazil, we calculated and validated the relevant summary statistics of Index P at the municipality level rather than at the spatial pixel level. Here, we included several analyses that support the application of Index P to explain past spatiotemporal dynamics of DENV, reaffirming the results of previous studies 5,24,[26][27][28][29][30][31][32] .…”

“…Local temperature and humidity time series are its main inputs, making its framework sufficiently general to be applied to any location for which such climate data exists and for any MBV for which there is empirical data on the relationship between climate and vector-viral traits. It has been successfully used to characterize the transmission potential and epidemiology of West Nile virus in Israel 27 , Portugal 28 , Brazil 29 , and Italy 30 , CHIKV and ZIKV in the Dominican Republic 5 and Mexico 31 , and DENV in Myanmar 26 , Brazil 24, 32 and Mexico 31 . So far, the application of Index P has been performed at a small scale driven by specific and limited research goals.…”

West Nile Virus Infection: A Cross-Sectional Study on Italian Medical Professionals during Summer Season 2022

“…Risk perception and knowledge status were not only correlated (Spearman's rho = 0.156; p value = 0.013), but scoring a better knowledge status was identified as a positive effector for reporting higher risk perception (aOR 2.92, 95%CI 1.60 to 5.30). Still, even though the present study was performed during an unprecedent reporting season for WNV [41,42], participants were characterized by a relatively low risk perception (RPS 37.7% ± 17.5). In fact, WNV infections were generally considered as a lesser threat for public health than more "conventional" pathogens such as Mycobacterium tuberculosis and HIV, as well as SARS-CoV-2.…”

“…Even though the potential burden of WNV infections was perceived akin to that associated with an important pathogen such as seasonal influenza, the latter is often underscored as a relatively indolent disorder, not only in the general population but also among Italian medical professionals [50][51][52], and the correspondent vaccine has been in turn often discredited by media [53][54][55][56][57][58][59]. A possible explanation may be found in the coverage of conventional and new media on the ongoing WNV outbreak in Northern Italy [40][41][42]. While an accurate measurement of the qualitative and quantitative coverage of a specific topic by conventional media remains particularly difficult to achieve, with obvious consequences on the eventual modeling of knowledge, beliefs, and perceptions of targeted study group, a proxy for new media has been developed and provided by Google TM through Google Trends™ and the calculation of relative search volumes (RSV).…”

“…Some explanations may be found in the characteristics of targeted professionals [74,75], as the individual expertise of occupational physicians-medical professionals primarily involved in health surveillance and preventive interventions in the workplaces-can be hardly compared to that of other medical professionals [47,48,[75][76][77]. Another substantial factor could be identified in the decrease in notification rates for WNV infections between 2020 and 2021 [19,38,39], which was then followed by the unprecedented reporting season 2022, which was also characterized by a particularly high case fatality ratio [40][41][42]. In other words, after two reporting seasons with a low or even a very low circulation of the pathogen, participants may have been led to the perception of WNV as a relatively uncommon disorder, while the high lethality reported in 2022 could have inflated the perceived severity of WNV infections.…”