A new report from the University of Padua said the strain of West Nile first detected last month was different from the virus that caused outbreaks in Italy's Veneto region in 2008 and 2009.
Health officials in the area were urged by the researchers to increase their surveillance of mosquito-borne West Nile, Italy's ANSA news agency said.
West Nile has been appearing more frequently in the Mediterranean and Eastern European nations in recent years. The Padua study published in Eurosurveillance concluded the new virus had found a hospitable home in the area.
"This shows that the virus is able to winter in wetland areas near rivers, where it probably has established its endemic cycle", said Giorgio Palu, one of the authors of the study.
Meanwhile, The United States is suffering from the worst West Nile virus outbreaks on record and the number of cases is still growing, federal health officials said.
So far this year 1,118 cases and 41 deaths have been reported, representing "the highest numbers of West Nile virus disease cases reported to CDC through the third week in August since West Nile virus was first detected in the United States in 1999," Centers for Disease Control and Prevention vector-borne diseases Director Dr. Lyle Petersen said.