nov 21 2019
Seroprevalence studies in Italy indicate that the prevalence of antibodies against USUV in humans is higher than anti-WNV antibodies in areas where both viruses co-circulate [5-8], supporting the speculation that most human USUV infections are asymptomatic.
Several cases of asymptomatic USUV infection were accidently identified when blood donors were screened with WNV nucleic acid amplification tests (NAT) that cross-react with other flaviviruses [9-14].
Symptomatic USUV infections in humans are uncommon; only 20 cases have been described in the literature so far including: (i) two cases with fever from Africa [15], (ii) one blood donor with a rash from Austria [14], (iii) 13 cases with neuroinvasive disease from Italy [6,16,17], (iv) three cases presenting as meningoencephalitis, encephalitis and polyneuritis from Croatia [18], and (v) one case with facial paralysis from France [19].
In Italy, USUV infection is a notifiable disease and USUV surveillance has been included in the national plan since 2017 [20].
To improve knowledge on USUV disease in humans, we describe clinical and virological findings and the results of follow-up investigation of eight symptomatic USUV infection cases identified in the Veneto Region of northern Italy during the 2018 transmission season.
Seroprevalence studies in Italy indicate that the prevalence of antibodies against USUV in humans is higher than anti-WNV antibodies in areas where both viruses co-circulate [5-8], supporting the speculation that most human USUV infections are asymptomatic.
Several cases of asymptomatic USUV infection were accidently identified when blood donors were screened with WNV nucleic acid amplification tests (NAT) that cross-react with other flaviviruses [9-14].
Symptomatic USUV infections in humans are uncommon; only 20 cases have been described in the literature so far including: (i) two cases with fever from Africa [15], (ii) one blood donor with a rash from Austria [14], (iii) 13 cases with neuroinvasive disease from Italy [6,16,17], (iv) three cases presenting as meningoencephalitis, encephalitis and polyneuritis from Croatia [18], and (v) one case with facial paralysis from France [19].
In Italy, USUV infection is a notifiable disease and USUV surveillance has been included in the national plan since 2017 [20].
To improve knowledge on USUV disease in humans, we describe clinical and virological findings and the results of follow-up investigation of eight symptomatic USUV infection cases identified in the Veneto Region of northern Italy during the 2018 transmission season.