Diagnosis of the canine parvovirus in faecal samples by in situ hybridization

Election microscopy (EM), in situ hybridization (ISH) and PCR were applied to compare their sensitivity and specificity for detection of CPV infection in 50 diarrheal faecal samples obtained from CPV infection of dogs. Negative stain with 3% phosphotungstic acid was used to detect virus particles by Em. Viral particles were demonstrated in 37 out of 50 faecal samples (74%). A biotinylated probe was designed in a part of CPV capsid protein VP2 and used for ISH. All steps of ISH were conducted within 2 hours. Specific positive signals for CPV were detected in 46 diarrheic faecal samples (92%). A pair of specific primers for CPV VP2 gene was designed and used for PCR. Forty nine faecal samples (98%) showed a band of expected size. The sensitivity of ISH in comparison with that of PCR was 93.9% and its specificity was 100% (κ=0.61) and in comparison with EM was 100% and the specificity was 30.8% (κ=0.40). These results suggest that ISH may be a rapid and sensitive diagnostic method for detection of CPV in the faecal samples. Therefore, this technique is likely to become a valuable method for the laboratory diagnosis of CPV infection.