Utility of battery of tests for accurate serodiagnosis of dengue

Abstract

Introduction: Inview of high morbidity and mortality associated with dengue, its imperative to have rapid and sensitive laboratory tools for early detection of the disease. Serological diagnosis of dengue by antibody testing though performed routinely is considered confirmatory if paired serum samples are tested. This is the practical problem in health care settings where patients after receiving adequate health care are discharged making followup difficult and only single serasample is available for serodiagnosis. Dengue diagnosis can also be arrived at by PCR and NS1 antigen detection. However, these tests also have their own set of limitations. This study is undertaken to access the utility of battery of these tests when carried out on a single specimen for accurate serodiagnosis of dengue. Materials and Methods: One forty four samples received from clinically suspected dengue cases with fever of 1-9 days were subjected to panel of tests viz. Dengue NS1 antigen capture ELISA, Dengue IgM antibody capture ELISA and Dengue PCR simultaneously. Results: Out of 144 samples tested, 28.4%, 34.02%, and 40.9% were positive for dengue NS1 antigen ELISA, PCR and IgM antibody ELISA respectively. Based on the dual combination, NS1 antigen ELISA+PCR, NS1 antigen ELISA+IgM antibody ELISA and PCR+IgM antibody ELISA, 37.5%, 48.6%, and 51.38% of patients were positive respectively. Combination of all the 3 tests yielded 63.19% of specimens positive for DENV infection. Conclusion: No solitary laboratory test is enough to diagnose all acute cases of dengue infection. Hence when NS1antigen detection or PCR is combined with antibody detection on same specimen, the possibility of missing out dengue infection be minimized and an accurate serodiagnosis of dengue infection can be achieved.