Human and entomological surveillance of Toscana virus in the Emilia-Romagna region, Italy, 2010 to 2012

Abstract

Toscana virus (TOSV), transmitted by phlebotomine sandflies, is recognised as one of the most important causes of viral meningitis in summer in Mediterranean countries. A surveillance plan based on both human and entomological surveys was started in 2010 in the Emilia-Romagna region, Italy. Clinical samples from patients with neurological manifestations were collected during 2010 to 2012. The surveillance protocol was improved during these years, allowing the detection of 65 human infections. Most of these infections were recorded in hilly areas, where sandflies reach the highest density. Entomological sampling around the homes of the patients resulted in a low number of captured sandflies, while later sampling in a hilly area with high number of human cases (n=21) resulted in a larger number of captured sandflies. Using this approach, 25,653 sandflies were sampled, of which there were 21,157 females, which were sorted into 287 pools. TOSV RNA was detected by real-time PCR in 33 of the pools. The results highlighted the role of Phlebotomus perfiliewi as the main vector of TOSV and a potential link between vector density and virus circulation. This integrated system shows that an interdisciplinary approach improves the sensitiveness and effectiveness of health surveillance.

Detection of Specific Antibodies against Toscana Virus among Blood Donors in Northeastern Italy and Correlation with Sand Fly Abundance in 2014

“…In this study, we observed that anti-TOSV positive BDs resided mainly in municipalities of the Bologna province, while no active TOSV circulation was observed in the Ferrara province; these findings match with estimated abundance of sand flies in these two provinces of Northeastern Italy. Between 2010 and 2013, 143 cases of neuroinvasive infection caused by TOSV were identified in the Emilia-Romagna region, Northeastern Italy; the highest number of TOSV cases was recorded in the Bologna province and the lowest number in the Ferrara province [17,18]. In line with the distribution of symptomatic TOSV cases, our serosurvey identified a high circulation of TOSV in the Bologna province, with a seroprevalence of 6.8%, while no TOSV circulation was observed in the Ferrara province.…”

“…Since 1999, autochthonous human cases of TOSV meningitis have been reported in the Emilia-Romagna region (Northeastern Italy), indicating local circulation of the virus [16]. In 2010, a surveillance plan to monitor human arboviral cases was adopted by the Emilia-Romagna region, leading to the detection of 61 cases of TOSV meningitis or meningoencephalitis in 2010-2012 [17] and 82 cases in summer-autumn 2013 [18]. Two sand fly species are present in the Emilia-Romagna region, i.e., Ph.…”

“…To verify this hypothesis, we performed a serosurvey for the identification of anti-TOSV antibodies among blood donors (BDs) in the Emilia-Romagna region. The study was carried out in April-July 2014, involving the central-eastern part of the region; sera were collected from BDs in areas with the highest and lowest number of neuroinvasive cases in previous years, i.e., the provinces of Bologna and Ferrara, respectively [17]. Serum samples were firstly evaluated for the presence of specific IgG by ELISA and only reactive samples were further tested by indirect immunofluorescence assay (IIF) and by microneutralization assay (MN).…”

European Network for Neglected Vectors and Vector-Borne Infections COST Action Guidelines: What Is This About and What Is This For?

“…During the last decade, existing and novel phleboviruses have been described. Several new phlebovirus detection and isolations have recently been reported globally , Papa et al 2011, Calzolari et al 2014, Palacios et al 2015, Baklouti et al 2016. The identified viruses could be used as a guide; year, location, and sample used for detection/isolation may give hints for possible other phleboviruses in circulation.…”

“…During World War II, a large number of soldiers was affected by sandfly fever . Recently, TOSV human case records came from Italy (Serata et al 2011, Calzolari et al 2014, France (Dupouey et al 2014, Marlinge et al 2014, Portugal (Santos et al 2007, Amaro et al 2011), Croatia (Punda-Polić et al 2012, Turkey (Ocal et al 2014, Greece (Papa et al 2014), and Tunisia (Fezaa et al 2014) (Fig. 3).…”