Catching Dengue Early: Clinical Features and Laboratory Markers of Dengue Virus Infection.

BACKGROUND AND OBJECTIVES Dengue fever is one of the most common tropical diseases worldwide. Early diagnosis of dengue helps in patient triage and timely management of dengue virus infection.This study was undertaken to note the early clinical features supported by detection of NS1 antigen for diagnosis of dengue virus infection. METHODOLOGY In this study a total of 100 adult patients presenting with clinical features of dengue infection from January 2012 to December 2012 were studied.The diagnosis was confirmed with NS1 rapid diagnostic test (RDT) whose efficacy was later tested with IgM ELISA. RESULTS In this study young males were predominantly affected. NS1 positivity was 68%. The sensitivity of NS1 in predicting dengue infection compared to IgM was 92.86% and specificity was 90% with strength of agreement considered to be 'very good' based on Kappa statistics. Clinical features like retro-orbital pain, myalgia, arthralgia, rashes and bleeding manifestations were significantly associated with NS1 positivity. Similarly icterus, oedema, hypotension, altered sensorium, thrombocytopenia and raised creatinine were significantly more in NS1 positive patients. Anomalously, SGOT was more than SGPT, which can help in differentiating dengue virus infection from other viral infections early in the course. CONCLUSION We conclude that dengue infection, which possesses serious public health problem, can be diagnosed early with the help of clinical features like retro-orbital pain, myalgia, bleeding manifestations, thrombocytopenia and anomalously SGOT greater than SGPT that is supported by detection of NS1 antigen.