Prevalence of Angiostrongylus vasorum in southern Belgium, a coprological and serological survey.

BACKGROUND: Canine angiostrongylosis, a gastropod-borne helminthic infection, is increasingly being described in North America and is now reported in many European countries. In dogs, Angiostrongylus vasorum may cause a wide spectrum of clinical signs. Respiratory distress such as coughing and dyspnoea are the most frequently described manifestations. The aim of the present study was to gain additional information on the distribution, prevalence and risk factors associated with A. vasorum infection in dog from southern Belgium through the combined used of a commercially available in-clinic assay for detection of circulating antigen (Angio Detect, IDEXX, Westbrook, USA) and coprology in two different canine populations: dogs with clinical signs compatible with angiostrongylosis and asymptomatic dogs or dogs presented for unrelated conditions (control). RESULTS: A total of 979 dogs were enrolled in the study from November 2014 until February 2016. Seven hundred fifty-seven dogs were included in the control group, whereas 222 dogs had clinical signs compatible with angiostrongylosis. Forty-six dogs out of 979 (4.7 %) had A. vasorum circulating antigen. There was a highly significant difference between the two populations (3.6 % (27/747) and 8.6 % (19/222) in control and symptomatic dogs, respectively) (P = 0.00379). First stage larvae (L1) of A. vasorum were found in seven out of 24 serologically positive control dogs and in six out of 17 serologically positive symptomatic dogs. Interestingly, L1 of Crenosoma vulpis were detected by Baermann technique in one control and nine symptomatic dogs, respectively. Out of 17 Angio Detect (IDEXX, Westbrook, USA) positive dogs with negative (14) or not performed Baermann test (three), one dog was positive in both in-house ELISAs (Ag and Ab) and one dog was positive for Ag. Statistical analysis was unable to detect any risk factors associated with the direct and/or indirect detection of A. vasorum. CONCLUSIONS: This seroepidemiological study demonstrated for the first time a high seroprevalence in Southern Belgium for A. vasorum. The Angio Detect was found to be suitable in this context as the collection, preservation and examination of stools were difficult. Nevertheless, discrepancies were observed between the different available tests. Additional research is clearly needed. Also, coproscopy remains a very useful tool in dogs infected for less than nine weeks and for the identification of other canine lung nematodes such as C. vulpis. This study also demonstrates that asymptomatic dogs may shed A. vasorum L1 in their faeces and therefore contribute to the maintenance of A. vasorum life-cycle

Fifth European Dirofilaria and Angiostrongylus Days (FiEDAD) 2016

Peer reviewe

Delivery of mengovirus-derived RNA replicons into tumoural liver enhances the anti-tumour efficacy of a peripheral peptide-based vaccine.

International audienceHepatocellular carcinoma is a deadly cancer with growing incidence for which immunotherapy is one of the most promising therapeutic approach. Peptide-based vaccines designed to induce strong, sustained CD8+ T cell responses are effective in animal models and cancer patients. We demonstrated the efficacy of curative peptide-based immunisation against a unique epitope of SV40 tumour antigen, through the induction of a strong CD8+ T cell-specific response, in our liver tumour model. However, as in human clinical trials, most tumour antigen epitopes did not induce a therapeutic effect, despite inducing strong CD8+ T cell responses. We therefore modified the tumour environment to enhance peptide-based vaccine efficacy by delivering mengovirus (MV)-derived RNA autoreplicating sequences (MV-RNA replicons) into the liver. The injection of replication-competent RNA replicons into the liver converted partial tumour regression into tumour eradication, whereas non-replicating RNA had no such effect. Replicating RNA replicon injection induced local recruitment of innate immunity effectors (NK and NKT) to the tumour and did not affect specific CD8+ T cell populations or other myelolymphoid subsets. The local delivery of such RNA replicons into tumour stroma is therefore a promising strategy complementary to the use of peripheral peptide-based vaccines for treating liver tumours