Significance of Serological Markers in Diagnosis of Acute Dengue Infection: 2021 Outbreak

Objective: To highlight the significance of Dengue anti-IgM and Dengue NS1 antigen in diagnosing Acute Dengue infection. Study Design: Cross-sectional study. Place and Duration of Study: Virology Department, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Sep to Nov 2021. Methodology: One hundred and fifty Dengue NS1-positive patients of either gender with age≥5 years were included. ELISA tested patients for detection of Dengue anti-IgM antibody. A questionnaire was used to collect demographic and personal data of each patient. Results: Out of 150 dengue NS1 positive samples, 26(17%) were positive for dengue anti-IgM. In collected samples, Dengue serological markers (NS1 and anti-IgM) positivity was observed based on ‘the day of onset of symptoms. On days 1 and 2, 54 and 44 NS1 positive samples were collected, respectively, but no one was found positive for anti-IgM. Anti-IgM was detected on day-3 and onwards. 27% Dengue anti-IgM positivity was found on day-3, which increased gradually as the time of infection increased. On day four, it was 53%; on day 5, it was 55%; on day-6, it was 60%; on day 7, it was 75%; and on day 8, it was 100%. Conclusions: The findings of present study suggested that anti-Dengue IgM antibodies are less significant than the Dengue NS1 antigen in diagnosing acute dengue infection.