Serotype and genotype analysis of dengue virus by sequencing followed by phylogenetic analysis using samples from three mini outbreaks-2007-2009 in Pakistan

Abstract

BackgroundSince the first reported outbreak of dengue hemorrhagic fever in Pakistan, several mini outbreaks have erupted in the region. Dengue virus serotype 3 (DEN-3) was first documented in 2005 outbreak in Karachi. Reports show that serotype 3 is prevalent in Lahore since 2008. Serotype 2 (DEN-2) is the major circulating serotype in Pakistan as it is documented since 1994. We have conducted a detailed study of three outbreaks of dengue virus infection that occurred in years 2007, 2008 and 2009 in Lahore by using molecular techniques such as PCR and nucleotide sequencing of the C-prM gene junction of Dengue virus.ResultsThrough the analysis of 114 serum samples collected over the period of three years (2007-2009), total 20 patients were found to be infected with dengue virus. In year 2007, four were positive for serotype 2 and one sample was positive for serotype DEN-3. In 2008, five samples had concurrent infection with serotypes DEN-2 and DEN-3 while three samples were infected only with serotype DEN-2. In year 2009, one sample had concurrent infection with serotypes DEN-2 and DEN-3 while six were positive for serotype DEN-2 only.ConclusionsOur study showed that serotype DEN-2 was dominant in positive samples of dengue virus infection collected during the period of three years (2007-2009). The other serotype present was serotype DEN-3. Genotypes of serotype DEN-2 and serotype DEN-3 were subtype IV and subtype III, respectively.

Dengue Virus Serotype 2 (DEN-2): the Causative Agent of 2011-Dengue Epidemic in Pakistan

“…Only DENV RNA PCR positive samples were included in the study. DENV PCR was done as described previously (1). Briefly, viral RNA was extracted from patients' serum samples using Nucleospin Viral RNA Extraction Kit (Macherey-Nagel, Germany) following RNA isolation procedure given in the kit protocol.…”

“…Dengue (DEN) the most common vectorborne viral disease in humans; is currently one of the most significant emerging diseases that challenges the global public health worldwide particularly in tropical and subtropical countries (1,2). The causative agent of dengue fever is dengue virus (DENV).…”

RNAi: antiviral therapy against dengue virus

“…DENV is a member of Flaviviridae family and is transmitted to humans by infected female Aedes genus, especially Aedes aegypti or Aedes albopictus [3,4] . There are four serotypes of dengue virus (DENV [1][2][3][4] that manifest with similar symptoms [5,6] . Two types of infections are caused by DENV, namely, primary infection and secondary infection.…”

“…There are four serotypes of DENV (DENV types [1][2][3][4]. Humans are main amplifying host of the virus and they circulate virus in their blood at approximately same time as they have fever, and other Aedes spp.…”

Immunogenicity Prediction by VaxiJen: A Ten Year Overview

“…There are four DENV serotypes and several genotypes [94]. The DENV genome encodes 3 structural (capsid C, precursor of membrane prM and envelope E) and 7 non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5).…”