title: Emergence of dengue virus type-3 in northern India.
abstract: 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.
authors.affiliation: Division of Virology, Defence Research and Development Establishment, Gwalior, India.
authors.forename: Paban Kumar
authors.initials: PK
authors.lastname: Dash
authors.forename: Parag
authors.initials: P
authors.lastname: Saxena
authors.forename: Ajay
authors.initials: A
authors.lastname: Abhyankar
authors.forename: Rakesh
authors.initials: R
authors.lastname: Bhargava
authors.forename: Asha Mukul
authors.initials: AM
authors.lastname: Jana
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D002675:Child, Preschool; D021821:Communicable Diseases, Emerging / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D003715:Dengue / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D003716:Dengue Virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004196:Disease Outbreaks; D004199:Disease Vectors; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007194:India / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D051379:Mice; D012367:RNA, Viral / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016036:Seroepidemiologic Studies
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012367:RNA, Viral