Detection of koi herpesvirus in healthy common carps, Cyprinus carpio L.

Koi herpesvirus (KHV), a member of Hervesviridae, has been frequently reported to cause mass mortality (80-100%) in common carps (Cyprinus carpio L.). A unique feature of Herverviridae members is latent infection, maintaining their genetic information for an extended period in the absence of productive infection, and reactivate when environmental conditions are favorable for their growth. To prevent this occurs, a monitoring program should be done for early detection. This study aimed at detecting the presence of KHV in healthy common carps reared in West-Nusa Tenggara Province, Indonesia. A total of 80 healthy fish was collected randomly from eight fish farms (Lingsar, Batu Kumbung, Narmada, Tanjung, Lenek, Aik Mel, Brang Rea and Rhee) across West-Nusa Tenggara Province, Indonesia. The presence of KHV genome was detected using a PCR with a commercial kit, IQ 2000TM. The result showed that common carps collected from four farms (Aik Mel, Lenek, Rhee and Brang Rea) were positive KHV. The size of an amplified gene was ~ 550 bp which was the same as positive KHV control. The obtained result suggests that KHV as other member of Hervesviridae shows a latent infection in common carps, and should be anticipated for their reactivation. Based on this result it is highly recommended that common carps cultured in this region should be vaccinated. In addition, transporting common carp out from Lombok and Sumbawa Islands should be carefully regulated to prevent the spread of the disease to other areas.