广西凡纳滨对虾IHHNV感染情况的调查与分析

Investigation and analysis of infectious hypodermal and hematopoietic necrosis virus infection in Penaeus vannamei in Guangxi

【目的】了解凡纳滨对虾传染性皮下及造血组织坏死病毒（IHHNV）在广西的分布、流行特点及趋势，为研究制定广西对虾IHHN的综合防控措施提供参考。【方法】根据广西凡纳滨对虾养殖情况，分别在北海市、钦州市、防城港市设立监测区，每个监测区设3-5个监测点，2010-2012年每年5月和9月进行两次采样，应用PCR对采集样品进行IHHNV检测，阳性产物送至宝生物工程（大连）有限公司测序，并与NCBI数据库中的IHHNV序列进行比对。【结果】2010年共检测凡纳滨对虾298份，IHHNV阳性率62.1%；2011年共检测凡纳滨对虾300份，IHHNV阳性率44.3%；2012年共检测凡纳滨对虾299份，IHHNV阳性率32.1%；3年的检测结果均以北海市的IHHNV感染率最高。2010、2011和2012年虾苗和中成虾的IHHNV阳性率分别为49.6%和72.1%、35.5%和49.2%、27.3%和36.9%。2010、2011和2012年5月和9月的IHHNV阳性率分别为53.2%和71.8%、35.2%和50.6%、21.6%和37.0 %。【结论】2010-2012年IHHNV在广西凡纳滨对虾主要养殖地区均有不同程度的流行，且中成虾IHHNV阳性率高于虾苗，每年9月的IHHNV阳性率高于5月，但广西近年通过严格控制亲虾品质及引进无病毒感染种苗，凡纳滨对虾品质已得到提升，IHHNV感染呈逐年下降的趋势。

【Objective】The aims of the current research were to understand the distribution and prevalence of infectious hypodermal and hematopoietic necroses virus （IHHNV） infection among Penaeus vannamei （P. vannamei） in Guangxi and to provide useful information for prevention and control for IHHN.【Method】According to the P. vannamei cultivation of Guangxi, P. vannamei samples per year were collected in May and September during 2010-2012 from Beihai, Qinzhou and Fangchenggang. There were 3-5 monitoring spots in each city. The detection of IHHNV among P. vannamei samples was carried out using Polymerase Chain Reaction （PCR）. Positive products were sequenced by Zhibao Bioengineering （Dalian） Ltd., and compared with IHHNV sequences in NCBI database. 【Result】The IHHNV positive rate of 2010 was 62.1% among 298 P. vannamei samples. The IHHNV positive rate of 2011 was 44.3% among 300 P. vannamei samples. The IHHNV positive rate of 2012 was 32.1% among 299 P. vannamei samples. The IHHNV positive rate of juvenile and adult shrimp in 2010, 2011 and 2012 was 49.6% and 72.1%, 35.5%, and 49.2%, 27.3% and 36.9%, respectively. The IHHNV positive rate of May and September in 2010, 2011 and 2012 was 53.2% and 71.8%, 35.2% and 50.6%, 21.6% and 37.0%, respectively. 【Conclusion】There was prevalence of IHHNV infection to different extent in P. vannamei during 2010-2012 in major shrimp production areas of Guangxi, where there were higher infected rates of IHHNV in adult shrimp than in juvenile, and in September than in May. In recent years, Penaeus vannamei quality is improved with gradual reducing IHHNV infection rate owing to strict control over parent shrimp and virus-free seeds introduction.