Feline calicivirus is a common cause of respiratory disease in cats and kittens. Diagnosis of infection can be a challenge due to the fact that there are many strains of the virus. These investigators compared methods of virus detection from swabs for diagnosis of the condition. Using samples from 300 cats, virus isolation and detection by PCR were assessed, as were storage conditions of the swabs of affected cats. For virus isolation, temperature of 4C vs -20C did not affect results, but swabs stored in culture medium maintained a higher viral load longer.
Combined PCR on samples enriched first by virus propagation proved to be most sensitive, up to 96%. Neither PCR nor virus isolation alone were able to detect the virus in all positive samples. The authors concluded that samples for FCV detection should be stored in cell culture medium at or below 4C, processed as soon as possible, and propagated in cell culture prior to PCR detection for highest sensitivity. (MK)