EN
The purpose of the project was to study the correlation between the presence of the IHN virus and the presence of antibodies against this virus in fish sera. Experimental infection of rainbow trout was performed at temperatures of 12°C±1 and 15°C±1. The trouts’ sera were collected at 7-day intervals. Samples from farms naturally infected with IHNV were also tested. The presence of antibodies against IHNV was determined by seroneutralization and the virus was detected by isolation in cell culture. It was found that in the experimentally infected rainbow trout, antibodies against IHN were found earlier in the higher temperature, after 21 days post infection, whereas the presence of IHNV was observed to last longer in the lower temperature. In the study performed on 30 samples of sera from IHN-infected farms, antibodies were detected in 12 samples. Detection of antibodies against IHNV in fish serum can be a helpful tool supporting recommended techniques.