Evaluation of a rapid device for serological in-clinic diagnosis of canine angiostrongylosis

Background: angiostrongylus vasorum is a potentially fatal canine nematode. due to the high variability of clinical signs and the often chronic and subtle course of the infections,the diagnosis is particularly challenging. a rapid in-clinic assay (angio detect™ test,idexx laboratories,westbrook,maine,usa) for the serological detection of circulating antigen and intended for routine in-clinic diagnosis has been evaluated. methods. sensitivity was calculated with sera from 39 naturally infected dogs confirmed by baermann-wetzel analysis,while sera of 38 experimentally infected dogs were used for follow-up analyses,of which 10 were treated with imidacloprid/ moxidectin. cross-reactivity was tested with a total of 123 samples from dogs with proven parasitic infections with toxocara canis (n = 21),ancylostoma caninum (n = 4),crenosoma vulpis (n = 18),oslerus osleri (n = 3),eucoleus aerophilus,(n = 6),dirofilaria immitis (n = 28),dirofilaria repens (n = 20),acantocheilonema reconditum (n = 10) or dipetalonema dracunculoides (n = 10) or multiple infections (n = 3). all sera were tested with the angio detect™ test and with an elisa for detection of circulating antigen of a. vasorum. results: the sensitivity of the angio detect™ test was 84.6% (95% c.i. 69.5 - 94.1%),while specificity was 100% (95% c.i. 97.6 - 100%). the sensitivity of the elisa (94.9%,95% c.i. 82.7 - 99.3%) was comparable with previous evaluations. in experimentally infected dogs,earliest positive results with the angio detect™ test were observed 9 weeks post inoculation and 5 weeks later all sera were angio detect™ test positive. after anthelmintic treatment,seropositive dogs turned negative again within 3 to 7 weeks after treatment. the evaluation of the colour intensity of the test strips confirmed the delay of approximately 3-4 weeks for antigen detection by the angio detect™ test compared to the elisa and its correlation with the time after infection. conclusions: this study provided evidence of a good sensitivity and a very high specificity of the rapid device angio detect™ test for detection of circulating a. vasorum antigen in dogs with suspected canine angiostrongylosis,representing a very simple and useful tool to be broadly applied in veterinary practices. the rapid detection of infected dogs is a key point for initiating an indispensable and urgent therapy. © 2014 schnyder et al.; licensee biomed central ltd.