Effect of vaccination on parvovirus antigen testing in kittens

• Published in: Journal of the American Veterinary Medical Association Vol. 230; no. 3; pp. 359 - 363
• Main Authors: Patterson, E.V, Reese, M.J, Tucker, S.J, Dubovi, E.J, Crawford, P.C, Levy, J.K
• Format: Journal Article
• Language: English
• Published: United States 01-02-2007
• Subjects: Animals; Animals, Newborn; Antigens, Viral; cat diseases; Cat Diseases - diagnosis; Cat Diseases - immunology; Cat Diseases - prevention & control; Cats; diagnostic techniques; disease diagnosis; feces; Feces - virology; Feline Panleukopenia - prevention & control; Feline panleukopenia virus; Feline Panleukopenia Virus - immunology; Female; Hemagglutination Inhibition Tests; immune response; inactivated vaccines; kittens; live vaccines; Male; Parvoviridae Infections - diagnosis; Parvoviridae Infections - veterinary; Parvovirus - immunology; pets; Sensitivity and Specificity; seroconversion; serodiagnosis; Specific Pathogen-Free Organisms; Vaccination - adverse effects; Vaccination - veterinary; Vaccines, Attenuated; vertebrate viruses; viral antigens; Viral Vaccines - immunology
• ISSN: 0003-1488; 1943-569X
• DOI: 10.2460/javma.230.3.359

To determine the frequency and duration of feline panleukopenia virus (FPV) vaccine-induced interference with fecal parvovirus diagnostic testing in cats.
Prospective controlled study.
Sixty-four 8- to 10-week-old specific-pathogen-free kittens.
Kittens were inoculated once with 1 of 8 commercial multivalent vaccines containing modified-live virus (MLV) or inactivated FPV by the SC or intranasal routes. Feces were tested for parvovirus antigen immediately prior to vaccination, then daily for 14 days with 3 tests designed for detection of canine parvovirus. Serum anti-FPV antibody titers were determined by use of hemagglutination inhibition prior to vaccination and 14 days later.
All fecal parvovirus test results were negative prior to vaccination. After vaccination, 1 kitten had positive test results with test 1, 4 kittens had positive results with test 2, and 13 kittens had positive results with test 3. Only 1 kitten had positive results with all 3 tests, and only 2 of those tests were subjectively considered to have strongly positive results. At 14 days after vaccination, 31% of kittens receiving inactivated vaccines had protective FPV titers, whereas 85% of kittens receiving MLV vaccines had protective titers.
Animal shelter veterinarians should select fecal tests for parvovirus detection that have high sensitivity for FPV and low frequency of vaccine-related test interference. Positive parvovirus test results should be interpreted in light of clinical signs, vaccination history, and results of confirmatory testing. Despite the possibility of test interference, the benefit provided by universal MLV FPV vaccination of cats in high-risk environments such as shelters outweighs the impact on diagnostic test accuracy.