Mass mortality associated with koi herpesvirus in common carp in Iraq

Mustafa Ababneh,Wael Hananeh,Mohammad Alzghoul

doi:10.1016/j.heliyon.2020.e04827

Mustafa Ababneh, Wael Hananeh + Show 1 more

Open Access

https://doi.org/10.1016/j.heliyon.2020.e04827

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Journal: Heliyon	Publication Date: Aug 1, 2020
Citations: 11	License type: cc-by

Affiliation: Jordan University of Science and Technology

Abstract

Koi herpesvirus disease is a serious disease affecting both wild and common carp species in different continents throughout the world. Based on pathological and molecular findings, we document the presence of koi herpesvirus disease in Iraq as a cause of mass mortality among the common carp of the Tigris river. On a macroscopic level, the fish exhibited variably sized skin ulcerations throughout the entire trunk. The gills showed variable degrees of discoloration with an increased amount of slimy mucus. Microscopically, degeneration and necrosis with infiltration of a heterogenous population of inflammatory cells characterized different organs, primarily the skin and gills, with occasional intranuclear inclusion bodies that are consistent with koi herpesvirus disease. A semi-nested PCR assay coupled with sequencing confirmed the pathological diagnosis. Genotyping and sequence analysis of the TK gene, ORF 136 and markers I and II identified the isolated CyHV-3 as variant A1 of the Asian genotype TUSMT1 (J strain) displaying the I++II+ allele.

Highlights

Koi herpesvirus disease (KHVD), a serious disease affecting both wild and common carp species, is caused by the cyprinid herpesvirus 3 (CyHV3) [1]
This study was carried out to investigate the causative agent behind the mass mortality of carp fish in Iraq
Their study was conducted on 12 dead carp samples, 9 of which tested positive in real-time PCR for CyHV-3 and 3 of which tested positive in nested PCR for carp edema virus

Summary

Introduction

Koi herpesvirus disease (KHVD), a serious disease affecting both wild and common carp species, is caused by the cyprinid herpesvirus 3 (CyHV3) [1]. KHVD can occur on its own or as part of a coinfection alongside other viral agents such as carp edema virus [2]. Listed as a notifiable disease according to the International Office of Epizootics, KHVD first appeared in Germany in 1997 and soon spread to many countries in Europe, Asia, North America and Africa, causing huge losses in common carp and koi culture production [1]. Carp infected with CyHV-3 and kept at 23–28 C die between 5 and 22 days post infection (dpi), with peak mortality occurring between 8 and 12 dpi [1]. The virus can persist for some period of time in a latent or carrier state without obvious clinical signs [1]

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