Dengue fever is distinguished from dengue hemorrhagic fever (DHF) primarily by the presence of:

• A High fever above 40°C
• B Positive NS1 antigen in blood
• C Detection of IgM antibody by MAC-ELISA
• D Evidence of plasma leakage (hemoconcentration, pleural effusion, ascites) with thrombocytopenia ✓

Explanation

WHO classification distinguishes dengue fever from dengue hemorrhagic fever (DHF) by the critical criterion of plasma leakage — evidenced by hemoconcentration (haematocrit rise ≥20%), pleural effusion, or ascites — combined with thrombocytopenia (<100,000/µL) and fever. DHF grades III and IV (dengue shock syndrome) show circulatory failure. NS1 antigen and IgM ELISA confirm dengue infection but do not distinguish DF from DHF. High fever alone is present in both.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.