Blood samples (n = 323) were collected along with epidemiological and clinical data from suspected dengue patients who visited different hospitals in Swat and Mansehra district of Pakistan between May–November 2013 during a dengue outbreak. Samples were tested for the detection of viral nucleic acid by real-time PCR, non structural protein-1 (NS1) antigen and IgM antibodies by ELISA.
Out of 323 cases with clinical dengue infection, 304 were positive by one or more diagnostic parameter; 201 samples were positive by real-time PCR, 209 were positive by NS1 ELISA and 190 were positive by IgM antibodies. Sensitivities of real-time PCR and NS1 ELISA were comparable for early diagnosis of dengue virus infection, IgM antibody detection assay was found useful for the diagnosis in the samples collected later than day 5 of onset.
The use of real-time PCR or detection of non structural protein NS1 by ELISA followed by IgM antibodies detection can be recommended for early diagnosis of dengue virus infection with a high level of accuracy.