| The feline infectious nasal-conjunctivitis is a febrile infectious disease caused by feline calicivirus(FCV). The disease, together with feline infectious peritonitis and Feline infectious rhinotracheitis, is called the three most infectious diseases of cats. The major symptoms of this disease include upper respiratory tract infection,oral ulcer and biphasic fever. The kittens between two to three months are more susceptible to the disease, while seldom happen to cats over one year old. Not only cats, but also the wild felid can be infected by FCV. Presently, the virus has been isolated from big wild cats, like lions, cheetahs and so on. The disease has occurred worldwide, especially in America and Europe. Recently, due to an increase in the number of pet cats, FCV also spreads to our country. There are some reports of the disease in Jilin, Guangxi province and some other areas, in which mainly reported the virus isolation, identification and only few investigations about the etiology. In this study, nested RT-PCR and sandwich ELISA were used to detect samples(October 2014-September 2015) from different regions of Jilin province. We analyzed the number of cases and the rate of different ages and immune conditions within one year. The results showed that the samples from Tonghua had the highest morbidity of 20%,and the lowest rate from Liaoyuan with only 12.8%. Through the comparisons we find that cats of two to three months have the highest incidence rate of 18.65%,and the high risk group is the non-immunized kittens with an incidence rate of 21.63%. In a year, the highest incidence rate is 25% that happen in march.The product of nPCR,a 477 bp of part of ORF2, was cloned and sequenced. The sixteen sequences were analyzed and then aligned with the standard isolates including F4, F65, UTCVM-NH1, UTCVM-NH4, UTCVM-NH6 and the Chinese isolates CH-JL-1, CH-JL-2, CH-JL-3, CH-JL-4 and CH-SH by the Clustalx and Mega 5.0 software. The results indicate that the sequences of samples from Changchun and Jilin have a close relationship and they are in the same branch with CH-JL-2and CH-JL-4, indicating that they may the genetic variants of a same strain; Besides, the data also indicate that the samples from Tonghua are closely related to the Australian standard strain F65; the samples from Baicheng and Liaoyuan are closely related to the CH-SH isolate. However, the three kind of sequences are distantly related, further indicating that large variations may have occurred in the epidemic FCV in Changchun city, Jilin city, Tonghua city, Baicheng city and Liaoyuan city. |
