Standardized Incidence Ratio dataset of Human West Nile Virus in Italy (2012-2024)

West Nile Virus (WNV) is transmitted by mosquitoes that feed on viremic birds. Humans, horses, and other mammals act as dead-end hosts. It is responsible for the West Nile fever which can cause, in severe cases, neuroinvasive disease in humans. First detected in Italy in 1998 in horses, the virus was initially absent in humans. After a multispecies surveillance plan was launched in 2001, a large-scale outbreak occurred in northern Italy in 2008. Since then, WNV circulation has intensified, with Culex pipiens identified as the main vector. This study provides a dataset from 2012 to 2024, including standardized incidence ratio (SIR) values for human WNV cases at the NUTS-3 (provincial) level in Italy, aiming at supporting local and national stakeholders in monitoring the virus distribution. The results show a significant correlation between mosquito positivity and high SIR values, suggesting that mosquito populations strongly influence the incidence of WNV. These results show an increasing trend in WNV cases in Italy, underlining the need to investigate the factors favouring this increase.