Diseases caused by infectious pathogens are common in grow-out shrimp culture. The emergence of two shrimp diseases viz. infectious myonecrosis virus (IMNV) and hepatopancreatic microsporidiosis which is caused by Enterocytozoon hepatopenaei (EHP), has resulted in substantial economic losses to shrimp farmers in India. Based on previous reports of IMNV disease outbreaks in a small cluster of farms, an attempt was made to study the horizontal spread of this disease along the east coast of India, by active surveillance in four districts of Andhra Pradesh and Tamil Nadu. The present investigation reports the cases of co-infection of IMNV and EHP in Penaeus vannamei shrimp farms in India. Among the 12 ponds investigated, shrimp in four ponds were infected only with IMNV; a single pond was infected with EHP and seven ponds with shrimp harbouring both the pathogens. Shrimp affected by IMNV exhibited white discolouration on the abdominal segments. The EHP-positive pond did not exhibit any apparent clinical signs. The co-infected shrimp exhibited clinical lesions of both IMNV and EHP. Histopathology revealed that the hepatopancreas of shrimp with signs of slow growth, showed cytoplasmic developmental stages of EHP in the tubular epithelial cells and sloughing of infected cells, releasing spores in the tubular lumen whereas, IMNV affected shrimps had shredding of muscle fibres, coagulative necrosis with haemocytic infiltration in striated muscles and hypertrophy of lymphoid organ (LO). Both the infections were further confirmed by PCR as well as sequencing.

中文翻译：

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印度东海岸南美白对虾养殖场传染性肌坏死病毒与肝对虾肠细胞动物共感染

由传染性病原体引起的疾病在养成虾养殖中很常见。两种虾病的出现即。传染性肌坏死病毒 (IMNV) 和肝胰腺微孢子虫病(EHP) 引起了印度虾农的重大经济损失。根据之前在一小群农场中爆发 IMNV 疾病的报告，通过在安得拉邦和泰米尔纳德邦的四个地区进行主动监测，试图研究这种疾病在印度东海岸的水平传播。本次调查报告了南美白对虾IMNV和EHP共感染病例。印度的养虾场。在调查的 12 个池塘中，4 个池塘的虾只感染了 IMNV；一个池塘感染了 EHP，七个池塘中的虾感染了两种病原体。受 IMNV 影响的虾在腹部节段出现白色变色。EHP 阳性池塘没有表现出任何明显的临床症状。共感染的虾表现出 IMNV 和 EHP 的临床病变。组织病理学显示，虾的肝胰腺有生长缓慢的迹象，在管状上皮细胞中显示出 EHP 的细胞质发育阶段，感染细胞脱落，在管腔中释放孢子，而受 IMNV 影响的虾有肌纤维断裂、凝固性坏死和横纹肌中的血细胞浸润和淋巴器官 (LO) 肥大。