Parida M M, Dash P K, Upadhyay C, Saxena P, Jana A M
Division of Virology, Defence Research & Development Establishment, Gwalior, India.
Indian J Med Res. 2002 Dec;116:248-54.
BACKGROUND & OBJECTIVES: An outbreak of febrile illness occurred between September to November 2001 in Gwalior, Madhya Pradesh affecting individuals mostly in the age group < 30 yr. A total of 312 febrile indoor patients suspected to have dengue infection were investigated.
The investigation included examination of blood samples from patients for dengue specific IgM and IgG antibodies, isolation of virus in suckling mouse pups and in C(6/36) cell line followed by confirmation and typing through reverse transcriptase-PCR and nested PCR.
The serological analysis of the 312 samples indicated 65 per cent positivity of which 21 per cent are of recent infection as indicated by the presence of IgM antibody and 78 per cent are found to be secondary in nature by showing the presence of IgG and/or IgM antibodies. The RT-PCR analysis of patients' sera employing dengue virus group specific conserved amplimer confirmed the etiological agent as dengue complex by showing the characteristic 511 bp amplicons. None of the antibody positive samples were found to be positive by RT-PCR. A total of 13 (6%) samples positive by RT-PCR, were processed for virus isolation in mouse pups and in C(6/36) cells. Of these 9 samples (80%) were confirmed positive for virus isolation as identified by RT-PCR.
INTERPRETATION & CONCLUSION: The typing of isolates by nested PCR employing serotype specific amplimer revealed 119 bp amplicon characteristic of dengue virus type-2 and thus confirming the outbreak attributed to dengue virus type-2.
2001年9月至11月间，印度中央邦瓜廖尔市爆发了一场发热疾病，主要影响30岁以下的人群。共对312名疑似感染登革热的发热住院患者进行了调查。
调查包括检测患者血液样本中的登革热特异性IgM和IgG抗体，在乳鼠和C(6/36)细胞系中分离病毒，随后通过逆转录聚合酶链反应（RT-PCR）和巢式PCR进行确认和分型。
对312份样本的血清学分析显示，阳性率为65%，其中21%为近期感染，这可通过IgM抗体的存在来表明，78%的样本通过显示IgG和/或IgM抗体的存在被发现为继发性感染。采用登革病毒组特异性保守扩增引物对患者血清进行RT-PCR分析，通过显示特征性的511 bp扩增子，确认病原体为登革热病毒复合体。RT-PCR检测中，未发现抗体阳性样本呈阳性。共有13份（6%）RT-PCR阳性样本在乳鼠和C(6/36)细胞中进行病毒分离处理。其中9份样本（80%）经RT-PCR鉴定病毒分离呈阳性。
采用血清型特异性扩增引物通过巢式PCR对分离株进行分型，结果显示出登革病毒2型特征性的119 bp扩增子，从而确认此次疫情由登革病毒2型引起。
