Emergence of dengue virus type-3 in northern India
Dash, P.Kumar.; Saxena, P.; Abhyankar, A.; Bhargava, R.; Jana, A.Mukul.
Southeast Asian Journal of Tropical Medicine and Public Health 36(2): 370-377
2005
ISSN/ISBN: 0125-1562 PMID: 15916043 Document Number: 257064
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 between October and December 2003. To determine the aetiology, we carried out serological, virological and molecular investigations of this outbreak. Blood samples were collected from patients with suspected dengue in Gwalior, Madhya Pradesh (n=64), and Delhi, India (n=12). 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 (42%) had only IgG antibodies (indicative of secondary infection). RT-PCR analysis 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 virus specific 389 bp amplicon. This study confirmed the reemergence of dengue 3 virus in a dominant form in India after nine years. Earlier, dengue 2 virus was implicated as the aetiology of a major dengue epidemic in Delhi in 1996, and in Gwalior in 2001. The implication of dengue 3 virus as the cause of a dengue haemorrhagic fever epidemic in neighbouring Sri Lanka and Bangladesh recently confirmed the reemergence of dengue type-3 as the dominant form on the Indian subcontinent.