Calzolari M., P. Gaibani, R. Bellini, P. Bonilauri, A. Albieri, A. Pierro, G. Maioli, G. Rossini, F. Defilippo, M. Tamba, F. Cavrini, S. Natalini, V. Sambri, P. Angelini, M. Dottori
Italian Journal of Tropical Medicine 16 (3-4): 57-63.
Usutu virus (USUV), an African Flavivirus, was detected for the first time in Europe in 2001. This virus had rarely been associated with disease in human but in Emilia-Romagna region USUV-related illnesses were reported in two immunocompromised patients in 2009 and USUV IgG-specific antibodies were recently identified in this region in four healthy blood donors with no history of flavivirus infection.
In 2009 and 2010 a widely presence of USUV was detected in Emilia-Romagna region trough a multidisciplinary surveillance system. The circulation of the virus in the environment was demonstrated by the relevant number of PCR-USUV positive mosquito pools, 147 out of 4,900 tested, and PCR-USUV positive birds 23 out of 2,483 tested, while the virus was PCR undetected in the tested human samples from 30 subjects with clinical symptoms of meningoencephalitis. The relevant level of USUV detected in the environment, in mosquitoes and birds, without human detections, suggest a low capability of USUV to infect humans.
This capability, though at low level, raising the potential pathogenicity of USUV for humans, at least in immunocompromised individuals, and pointing out the necessity to know the potential circulation of this virus in the environment and to test its presence in the blood bags.