Dash Paban Kumar, Saxena Parag, Abhyankar Ajay, Bhargava Rakesh, Jana Asha Mukul
Division of Virology, Defence Research and Development Establishment, Gwalior, India.
Southeast Asian J Trop Med Public Health. 2005 Mar;36(2):370-7.
During the last few decades dengue has reemerged in several parts of Southeast Asia, including India. A major outbreak of dengue infection occurred in northern India during October to December 2003. To determine the etiology, we carried out serological, virological and molecular investigations of this outbreak. A total of 76 dengue suspected patient blood samples were collected from Gwalior, Madhya Pradesh and Delhi, India. Serological investigations carried out using an in-house Dipstick ELISA protocol revealed the presence of anti-dengue antibodies in 53 patients. Twelve of them (22%) had a positive IgM response, indicative of primary infection, and 22 of them (42%) revealed only IgG antibodies, indicative of secondary infection. RT-PCR analysis employing dengue group specific amplimer revealed the presence of dengue specific RNA in four acute phase samples. These four RT-PCR positive samples were further processed for virus isolation in C6/36 cells and suckling mice, yielding four dengue virus isolates. The Nested PCR analysis employing serotype specific amplimer revealed the presence of dengue-3 specific 389 bp amplicon. This study confirmed the reemergence of dengue virus type-3 in a dominant form in India after a gap of nine years. Earlier, dengue virus type-2 was implicated as the etiology of a major dengue epidemic in Delhi in 1996 and Gwalior in 2001. The implication of dengue type-3 as etiology of a DHF epidemic in neighboring Sri Lanka and Bangladesh recently confirms the reemergence of dengue type-3 as the dominant form on the Indian subcontinent.
在过去几十年里，登革热在包括印度在内的东南亚多个地区再度出现。2003年10月至12月期间，印度北部发生了一次登革热感染的大规模疫情。为确定病因，我们对此次疫情进行了血清学、病毒学和分子学调查。总共从印度中央邦瓜廖尔市、德里市采集了76份登革热疑似患者的血样。使用内部试纸条酶联免疫吸附测定（Dipstick ELISA）方案进行的血清学调查显示，53名患者体内存在抗登革热抗体。其中12人（22%）IgM反应呈阳性，表明是初次感染；22人（42%）仅显示IgG抗体，表明是二次感染。采用登革热组特异性扩增引物的逆转录聚合酶链反应（RT-PCR）分析显示，4份急性期样本中存在登革热特异性RNA。对这4份RT-PCR阳性样本进一步在C6/36细胞和乳鼠中进行病毒分离，获得了4株登革热病毒分离株。采用血清型特异性扩增引物的巢式PCR分析显示存在389 bp的登革热3型特异性扩增子。本研究证实，登革热3型病毒在间隔9年后以主导形式在印度再度出现。此前，登革热2型病毒被认为是1996年德里和2001年瓜廖尔大规模登革热疫情的病因。最近，登革热3型病毒作为邻国斯里兰卡和孟加拉国登革出血热疫情的病因，证实了登革热3型病毒在印度次大陆以主导形式再度出现。
