Serosurvey Study of Toscana Virus in Domestic Animals, Granada, Spain

Abstract

Toscana virus (TOSV) is transmitted by infected sandflies. In Mediterranean countries, TOSV is one of the major viral pathogens involved in aseptic meningitis and meningoencephalitis in humans. It remains unclear if there are animal reservoirs able to maintain the virus through the cold months of the year, when the vector is not circulating. From May to October of 2006 and 2007, we conducted a serosurvey study on domestic animals from Granada province (southern Spain). TOSV was investigated in 1186 serum samples from horses, goats, pigs, cats, dogs, sheep, and cows by serology (indirect fluorescence assay), viral culture, and RT-polymerase chain reaction. Specific anti-TOSV antibodies were detected in 429 (36.2%) serum samples. The highest seropositivity rates were observed in cats (59.6%) and dogs (48.3%). These results suggest that an important percentage of the domestic animals have been infected by TOSV. Significantly different seroprevalence rates were detected in goats among distinct geographical areas. All viral cultures were negative. TOSV was detected by RT-polymerase chain reaction in only one serum sample from a goat. Thus, the studied animals do not seem to act as reservoirs for TOSV; otherwise, they could be amplifying hosts for the virus.

Potential Animal Reservoirs of Toscana Virus and Coinfections with Leishmania infantum in Turkey

“…12 In a recent serosurvey undertaken in Granada, Spain, another TOSV-endemic region where the virus could be detected in sandflies and clinical cases, a high seroprevalence rate for TOSV antibodies (36.2%) among 1,186 domestic animals was revealed. 13 Here, IgG detection rates of 64.3% in horses, 59.6% in cats, 48.3% in dogs, 32.3% in sheep, 22% in pigs, 17.9% in cows, and 17.7% in goats were reported. Though cross-reactions among phleboviruses within the sandfly fever Naples virus serocomplex cannot be excluded and might have resulted in an overestimation of the seroprevalence in this study, the overall data are compatible with a TOSV-endemic zone and in agreement with the feeding habits of P. perniciosus, the documented vector in the region.…”

“…32 Interestingly, attempts of virus isolation were unsuccessful in all samples and a low level of TOSV viremia was detected only in one goat, suggesting an ongoing virus circulation in the region with evidence of previous exposure and low incidence of recent infections. 13 In Tunisia, another Phlebovirus-endemic region, TOSV as well as Punique and Sandfly fever Sicilian virus exposure in dogs were identified, with 7.5% seroprevalence for TOSV. 33 It has further been suggested that dogs can be used as sentinel animals for monitoring Phlebovirus activity.…”

“…Up to date, limited evidence of TOSV infection in domestic and wild vertebrates has been documented, insufficient to suggest any significant role of animal reservoirs for viral persistence. 12,13 Thus, this mechanism is currently considered as negligible and the competent vectors are suggested as the reservoirs. 1,4 Leishmaniasis is another vector-borne disease representing a public health threat, which is endemic in over 80 countries and has been continuously reported in the Mediterranean region.…”

Canine Infections and Partial S Segment Sequence Analysis of Toscana Virus in Turkey

“…Several studies have revealed a probable epidemiologic interaction among these agents, as well as coinfected sandflies (Bichaud et al 2011, Es-Sette et al 2014, Faucher et al 2014. Crucial issues on the TOSV natural cycle and disease epidemiology have not yet been completely elucidated, and virus exposure in vertebrate species other than humans has only been superficially explored (Navarro-Mari et al 2011). Recently, canine and feline TOSV infections as well as Leishmania and TOSV coinfected dogs in the Mediterranean region of Turkey have been reported (Dincer et al 2015).…”

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

“…some of these viruses (Navarro-Marí et al 2011, Alkan et al 2013, Sakhria et al 2014, Dincer et al 2015, Tahir et al 2016); accordingly they can serve as sentinels for the presence of the corresponding viruses. There is no undisputable evidence that birds can be infected by sandfly-borne phleboviruses, but few studies have addressed this point.…”