Specific Antibody Detection in Dogs with Filarial Infections

Abstract

Dirofilariosis is a mosquito-transmitted disease of wild and domestic carnivores. Etiological diagnosis on canine Dirofilaria-infections is generally either based on the morphological or molecular characterization of microfilariae (L1), or in case of D. immi tis-infection on the detection of circulating antigens shed by mature female worms. However, these tests do not detect infections during the long prepatent period of 182 -238 days. We hereby present a monoclonal antibody based sandwich-ELISA used for on-plate purification of somatic antigen of adult D. immitis stages for the detection of antibodies against D. immitis and D. repens in dog sera. Sensitivity of the assay for D. immitis patent infections was calculated to be 93.8 % (95 % CI: 79.2 -99.2 %), and for patent D. repens-infections 100 % (95 % CI: 81.9 -100 %). Specificity was determined to be 98.6 % (95 % CI: 92.2 -100 %) with sera of 69 dogs from a non-endemic area. Cross-reactions against other nematodes such as Acantho cheilonema and Dipetalonema spp. (50 % and 66.7 %, respectively), Crenosoma vulpis (16.7 %), Capillaria aerophila (14.3 %) and naturally, but not experimentally infected dogs with Angiostrongylus vasorum (14.3 %) were present. However, in all positive dogs a residence in a filarial endemic area cannot be excluded. No positive reactions could be shown in experimentally infected dogs with Toxocara canis, Ancylostoma caninum and Trichuris vulpis. Dogs experimentally infected with D. repens showed seroconversion between 24 -80 days post inoculation (dpi), far earlier than beginning of patency (189 -259 dpi). Accordingly, the presented ELISA could be a supplementary or alternative tool for Original Article S82EndoparasitEs the diagnosis of Dirofilaria-infected dogs in low or non-endemic areas to document the contact rate and infection pressure.

New insights into the biology, diagnosis and immune response to Dirofilaria repens in the canine host

“…To the authors knowledge, this is only the second study reporting antibody response to D. repens somatic antigen in experimentally infected dogs. Joekel et al (2017) evaluated the antibody response in dogs naturally infected with several different filarial species. Three D. repens -experimentally infected dogs were also analyzed.…”

Sero-prevalence of Dirofilaria repens Infection in Dogs by Indirect-ELISA using Microfiarial and Adult Worm Antigen

“…The sensitivity of the indirect ELISA used in the present study was 100 per cent with both microfilarial antigen and adult worm antigen, whereas specificity was 64.09 and 72 per cent with microfilarial antigen and adult worm antigen respectively. Low specificity of indirect ELISA used in the present study compare to previous assays, indicate the increase in false positive results due to homologous helminth interspecies epitopes leading to cross-reactions (Joekel et al, 2017).…”

“…Presently, there are no commercial serological test kits are available for detection of D. repens. However, some researchers have conducted ELISA for the detection of specific antibodies in dogs using D. immitis adult worm excretory/secretory antigen and D. repens/ D. immitis adult worm somatic antigens (Cancrini et al, 2000;Simsek et al, 2011;Tasic et al, 2012 andJoekel et al, 2017).…”

“…Razi Jalali et al, (2010) reported that, the sensitivity and specificity of rapid heart worm antigen test kits in detection of D. immitis antigen was 98.5 and 100% respectively whereas, Joekel et al, (2017) found sensitivity and specificity of the monoclonal antibody based sandwich-ELISA assay for detection of antibodies against D. repens was 100 and 98.6 per cent respectively. The sensitivity of the indirect ELISA used in the present study was 100 per cent with both microfilarial antigen and adult worm antigen, whereas specificity was 64.09 and 72 per cent with microfilarial antigen and adult worm antigen respectively.…”

“…Some researchers conducted ELISA with D. immitis adult worm excretory/secretory antigen and D. repens/D. immitis adult worm somatic antigens for the detection of specific antibodies in dogs with filarial infections (Cancrini et al, 2000;Joekel et al, 2017). The present study was undertaken to determine seroprevalence of D. repens in dogs from Shivamogga and Mangalore regions of Karnataka using microfilarial and adult worm antigen of D. repens by Indirect-ELISA.…”