Detection of Antibodies Against Rabies Virus in Foxes Serum after Oral Vaccination Campaign in Buzău and Galați Counties

Abstract

Rabies is one of the most feared zoonotic diseases worldwide, caused by a virus of the genus Lyssavirus , Rhabdoviridae family. In order to evaluate the efficacy of oral vaccination campaigns of foxes against rabies, two methods are agreed by WHO and OIE, namely: the quantification of rabies antibodies and the detection of a biomarker (tetracycline). The aims of this study were consisting in the identification and quantification of rabies antibodies in foxes ( Vulpes vulpes ) after oral vaccination campaign in Buzau and Galati Counties. After 2015 wildlife rabies vaccination campaign, 27 blood samples from hunted foxes were collected in Buzau (19 samples) and Galati (8 samples) Counties. According to manufacturer's recommendations, rabies seroconversion was quantified using Platelia TM Rabies II Kit (Bio-Rad, France).In both counties were identified seropositive foxes following vaccination. Out of 19 samples from Buzau County, 3 samples overcome the requested seroconversion level (0.736 EU/ml, 0.933 EU/ml and 2.362 EU/ml), another 5 didn’t reach the seroconversion level according to PLATELIA™ RABIES II test and 11 samples had undetectable seroconversion (<0.125 EU/ml). Out of 8 samples from Galati County, 3 overcome the requested seroconversion level (2.963 EU/ml, 3.177 EU/ml and 3.456 EU/ml), 2 samples didn’t reach it (0.372 EU/ml and 0.439 EU/ml) and 3 samples had undetectable seroconversion (<0.125 EU/ml). Only 22.22% of serum samples overcome the requested level of rabies antibodies, and 25.93% remained under the requested level, according to PLATELIA™ RABIES II test. The results suggest that additional oral vaccination campaigns should be implemented in order to increase the proportion of foxes with optimal seroconversion level of rabies antibodies.