Correlation of clinical, biochemical and molecular profile of dengue with disease severity

The Indian subcontinent is endemic to dengue, with an estimated 33 million clinically apparent dengue cases annually, contributing to one-third of the total global dengue burden. This study aimed to assess the disease burden among dengue-suspected patients visiting our tertiary care center in North India and to explore the correlation between clinical-biochemical parameters in dengue fever or severe dengue with disease severity.

A total of 318 dengue patients were enrolled in dengue fever with/without warning signs (DF ± WS, n = 229) and severe dengue (SD, n = 89) cohorts. Demographical, clinical, and biochemical data were collected during recruitment. Blood samples were screened for dengue NS1 antigen and IgM antibodies using ELISA. Representative NS1 antigen-positive samples (n = 50) were further tested for dengue RNA and serotyping via reverse transcriptase RT-PCR, followed by phylogenetic analysis of 17 PCR-positive samples.

The mean age was 36.02 ± 14.73 years and 35.46 ± 13.61 years for DF ± WS and SD individuals, respectively. Among DF ± WS patients, 49 (21.4%) were NS1 antigen positive, 122 (53.28%) had dengue IgM, and 58 (25.32%) were positive for both. In the severe dengue cohort, 14 (15.73%) and 45 (50.56%) were positive for NS1 and IgM, respectively, with 30 (33.71%) patients positive for both NS1 antigen and IgM antibodies. Among the DF ± WS and SD cohort, 35/229 (15.29%) and 31/79 (39.25%) patients had IgG antibodies depicting secondary dengue. The majority of patients were from Chandigarh (n = 130), followed by Punjab (n = 85) and Haryana (n = 46). With approximately six days of illness at the time of enrolment, fever, joint pain, lethargy, vomiting, hematocrit, and rashes were present in more than 50% of cases in DF ± WS and SD patients. Severe dengue patients exhibited significant thrombocytopenia (88,340 ± 6,575/ml vs. 40,620 ± 5,280/ml) and elevated liver enzymes compared to DF ± WS (AST: 1506 ± 220.4 IU/L vs. 179.3 ± 16.79 IU/L; ALT: 906.8 ± 141.4 IU/L vs. 124.8 ± 10.17 IU/L; ALP: 169.3 ± 20.06 IU/L vs. 120.4 ± 7.14 IU/L). Among SD patients, 20 deaths (22.47%) were reported, primarily due to multiple organ dysfunction syndrome (MODS), while only two deaths occurred in the DF ± WS cohort for unrelated reasons. Sequencing revealed 14 and 3 isolates belonging to serotype-2 and serotype-4, respectively.

Elevated liver function tests and severe thrombocytopenia in dengue patients indicate progression towards severe dengue with high mortality. A notable prevalence of secondary dengue infection (39.25%) was found in severe cases, with serotype-2 predominating in the north-Indian population.

The online version contains supplementary material available at 10.1007/s13337-025-00930-0.