Open Access Highly Accessed Research article

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

Zareen Fatima1, Muhammad Idrees1*, Mohammad A Bajwa2, Zarfishan Tahir3, Obaid Ullah3, Muhammad Q Zia2, Abrar Hussain1, Madiha Akram1, Bushra Khubaib1, Samia Afzal1, Saira Munir1, Sana Saleem1, Bisma Rauff1, Sadaf Badar1, Mahrukh Naudhani1, Sadia Butt1, Mahwish Aftab1, Liaqat Ali1 and Muhammad Ali1

Author affiliations

1 Division of Molecular Virology, CEMB University of the Punjab, 87-West Canal Bank Road, Thokar Niaz Baig, Lahore-53700, Pakistan

2 Department of Gastroenterology, Sheikh Zayed Medical Complex, Lahore, Pakistan

3 Bacteriologist Laboratory, Institute of Public Health, 6-Birdwood Road, Lahore, Pakistan

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Citation and License

BMC Microbiology 2011, 11:200  doi:10.1186/1471-2180-11-200

Published: 10 September 2011



Since 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.


Through 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.


Our 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.