In 2016, famers reported mass mortality events in hybrid grouper within 2–4 weeks following transfer to sea cages on the northern coast of Bali. The objective was to obtain an aetiological diagnosis using a broad range of traditional and emerging diagnostic approaches. A group of 24 and 12 fish with and without clinical signs were sampled from 10 affected populations at 9 farms. Samples for histopathology, ectoparasites evaluation and molecular approaches for microbiology were obtained with a diagnostic post-mortem examination. Fish with clinical signs had a significantly higher likelihood of having pale anterior and posterior kidneys and a liver that was pale and reduced in size compared to fish without clinical signs. There were no differences in the prevalence and quantity of Megalocytivus (MCV) or nervous necrosis virus (NNV) in tissues observed from fish with and without clinical signs. Nearly 55 % of fish were infected with NNV irrespective of clinical signs. There were no histopathological lesions consistent with virial nervous necrosis and the NNV infections were considered subclinical. 80 % of grouper were infected with MCV, irrespective of clinical signs. A significant proportion of fish with clinical signs (true prevalence 94.4 %; 95 % CI 79–100) had observed megalocytes and pathology consistent with disease caused by ISKNV compared to those without clinical signs (true prevalence 47.2 %; 95 % CI 27–70). Metagenomic sequences generated using Illumina Miseq and taxonomically labelled using BlastN + revealed that the Megalocytivirus was 99.9 % similar to Infectious spleen and kidney necrosis virus (ISKNV). The unbiased sequencing did not detect any novel DNA viruses or bacterial pathogens of clinical significance. The monogenean, Benedenia epinepheli and a leech, Zeylanicobdela arugamensis were detected at 6/9 and 9/9 farms, respectively. Our approach identified several pathogens reported in grouper aquaculture with histopathology showing that ISKNV was a necessary cause for the mass mortality events.

2016年，famers报告在转移到巴厘岛北部海岸的海笼中后2-4周内，石斑鱼发生了大规模死亡事件。目的是使用广泛的传统诊断方法和新兴诊断方法来进行病原学诊断。从9个养殖场的10个受影响人群中取样了24条和12条有或没有临床体征的鱼。通过尸检诊断获得组织病理学，体外寄生虫评估和微生物学分子方法的样品。具有临床体征的鱼与没有临床体征的鱼相比，前肾和后肾苍白，肝脏苍白且尺寸缩小的可能性要高得多。Megalocytivus的患病率和数量没有差异鱼中观察到的（MCV）或神经坏死病毒（NNV），有无临床体征。无论临床症状如何，近55％的鱼类都感染了NNV。没有与病毒性神经坏死相一致的组织病理学病变，NNV感染被认为是亚临床的。无论临床症状如何，石斑鱼中有80％感染了MCV。与没有临床体征的鱼类（真实患病率47.2％； 95％CI 27-70）相比，具有临床体征（真实患病率94.4％； 95％CI 79–100）的鱼中有相当一部分观察到与ISKNV引起的疾病相一致的巨细胞和病理。 ）。使用Illumina Miseq生成并使用BlastN +进行分类标记的元基因组序列显示，巨噬细胞病毒的99.9％与感染性脾肾坏死病毒（ISKNV）。无偏测序没有检测到任何具有临床意义的新型DNA病毒或细菌病原体。分别在6/9和9/9农场中发现了单基因的Benedenia肾上腺素和水ech，Zeylanicobdela arugamensis。我们的方法通过组织病理学鉴定了石斑鱼养殖中报告的几种病原体，表明ISKNV是造成大规模死亡事件的必要原因。