Epidemiological Profile and Laboratory Characteristics of Dengue Virus Infection during 2011 Outbreak in Rawalpindi, Islamabad Pakistan

A total of 215 serum samples of clinically suspected dengue patients who presented to the tertiary care hospitals over a period of July-November 2011 were analyzed for the detection of dengue NS1 antigen, dengue IgM and IgG antibodies and 180 (83.7%) samples were found positive by one or more than one testing parameters. Of the 180 samples, 98 (54.4%) were positive to NS1, 168 (93.3%) were positive to IgM and 93 (51.6%) cases were positive to IgG only. Similarly, 93 (51.6%) were positive to both NS1 and IgM, 48 (26.6%) to NS1 and IgG, and 83 (46.1%) were positive to both IgM and IgG and 48(26%) were positive for NS1, IgM and IgG. A randomly selected subset of 50 serology positive samples were tested by, one step TaqMan real time fourplex RT-PCR assay. A total of 35/50 (70%) samples were found positive by PCR. Positive rates of dengue serotypes were 15/35 (42.8%), 11/35 (31.4%) and 9/35 (25.7%) for DENV-1, DENV-2 and DENV-3 respectively. No DENV-4 serotype was detected.