New In-Clinic Test for FeLV and FIV

July 22, 2010

Sand C, Englert T, Egberink H et al: Evaluation of a new in-clinic test system to detect feline immunodeficiency virus and feline leukemia virus infection, Vet Clin Pathol 39:210, 2009.

Feline leukemia (FeLV) and feline immunodeficiency virus (FIV) are both important pathogens of cats that often result in lifelong infection. Routine testing as well as testing of clinically ill cats is recommended, and is usually done using in-clinic test kits. For FeLV, these assays detect a viral protein, while for FIV, virus-specific antibody is detected. A new test system, Anigen Rapid FIV Ab/FeLV Ag test kit is now available on the European market. These investigators examined the diagnostic sensitivity and specificity of this new test kit on 300 samples using western blot as the gold standard for FIV infection, and polymerase chain reaction for FeLV infection; in addition, results were compared to those attained using the most commonly-used kit made by IDEXX (SNAP Combo). In comparison to the gold standard for FIV, the new Anigen test had a sensitivity of 88.9% and specificity of 97.7%, and for FeLV, a sensitivity of 40% and a specificity of 100%. In comparing to the IDEXX Combo SNAP test for FIV testing, the Anigen assay had one false positive result; the SNAP test had no false positive results. Both kits had one false negative result. For FeLV testing, neither kit had a false positive result, but the Anigen kit had 9 false negatives, while the SNAP kit had 7 false negative results. The investigators concluded that the new test performed very well, similar in performance to the SNAP Combo test. For both kits, any positive result should be confirmed with a second, more sensitive test, especially in healthy cats. [MK]

Related articles:
Levy J, Crawford C, Hartmann K et al: 2008 American Association of Feline Practitioners’ feline retrovirus management guidelines, J Feline Med Surg 10:300, 2008.