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Although rabies incidence has fallen sharply over the past decades in Europe, the disease is still present in Eastern Europe. Oral rabies immunization of wild animal rabies has been shown to be the most effective method for the control and elimination of rabies. All rabies vaccines used in Europe are modified live virus vaccines based on the Street Alabama Dufferin (SAD) strain isolated from a naturally-infected dog in 1935. Because of the potential safety risk of a live virus which could revert to virulence, the genetic composition of three commercial attenuated live rabies vaccines was investigated in two independent laboratories using next genome sequencing. This study is the first one reporting on the diversity of variants in oral rabies vaccines as well as the presence of a mix of at least two different variants in all tested batches. The results demonstrate the need for vaccine producers to use new robust methodologies in the context of their routine vaccine quality controls prior to market release.

Background: Over the recent decades, container-breeding mosquito species belonging to the genus Aedes have frequently been recorded far from their place of origin. Aedes koreicus was first reported in north-eastern Italy in 2011, in a region endemic for Dirofilaria immitis, the agent of canine heartworm disease. The vector competence of Ae. koreicus for D. immitis was here tested under laboratory conditions, by infecting mosquitoes with a local strain of D. immitis., Methods: Blood containing 3000 microfilariae/ml was offered to 54 mosquitoes (T group) while 29 were left as a control (C group). Mosquitoes killed at scheduled days post infection (dpi) and naturally dead were divided in head, thorax and abdomen and examined for D. immitis larval stages by dissection under a microscope and molecularly., Results: Of the 45 engorged mosquitoes in T, 32 (71.1%) scored positive for D. immitis larval stages. L3 were found as early as 8 dpi in the Malpighian tubules and then in the thorax, salivary glands, palp and proboscis. At the end of the study a total of 18 mosquitoes developed L3 giving an estimated infection rate at 12 dpi of 68.2% and a vector efficiency index of 25.2%. The rate of mortality in T group within the first 9 days post infection was significantly higher in T group (47.6%) than in C group (8.3%) (p < 0.01). The concordance between microscopy and PCR was high (0.8-0.9), however, a positivity for D. immitis in the head was found molecularly at 13 dpi, three days before microscopy., Conclusions: Aedes koreicus, a new invasive species for Europe, is most likely a competent vector of D. immitis being of potential relevance in the natural cycle of the parasite. This poses a new threat for animal and human health in endemic areas for dirofilariosis and enhances the risk of spreading the infection in previously non-endemic areas. These results stress the importance of active surveillance and control strategies to minimize the risk of introduction of invasive alien species.

Oral vaccination of foxes (OVF) is a powerful tool to combat rabies in wildlife, and large parts of western Europe have been freed from rabies using this tool. Nevertheless, the success of OVF, given with the number of campaigns needed to eliminate the disease, depends on many factors. This article for the first time focuses on and assesses difference in OVF with respect to the spatial setting of vaccinated areas with time. The size of the areas vaccinated with time and the size of the overlapping area of consecutively vaccinated areas are particularly considered. In order to integrate these two aspects into one single figure, an Area Index is proposed ranging between 0 and 1. A statistical analysis indicates that the number of campaigns needed for rabies elimination significantly decreases on condition that the total rabies endemic area is consecutively treated right from the beginning of oral vaccination. Hence, from an economical and environmental point of view, vaccination areas should be selected the way that guarantees an Area Index close to 1. The concept of an Area Index, as described here, is a useful tool not only in the context of OVF, but it could also be used for other control schemes against infectious diseases in wildlife.

A simple and rapid enzyme linked immunosorbent assay (ELISA) to detect rabies antibodies in field fox sera has been standardised and established in several European laboratories. The same panels of 100 coded sera were investigated by four laboratories using this ELISA assay and reference serum neutralisation techniques (fluorescent antibody virus neutralisation (FAVN) test and rapid fluorescent focus inhibition test (RFFIT)). This indirect ELISA technique is highly correlated with conventional seroneutralisation test on cell culture. Results obtained with this ELISA test provide an almost perfect agreement between laboratories while the agreement of FAVN test and RFFIT results is substantial and very satisfactory. In view of this study, this simple and rapid ELISA test is a suitable tool for evaluating the sero-conversion rate in fox populations following oral rabies vaccination campaigns in European countries.