Early diagnostic value of dengue virus NS1 antigen and nucleic acid testing

To analyze laboratory test results and clinical characteristics of dengue patients, providing a reference for early diagnosis and treatment.

A retrospective analysis was conducted on the serological and pathogenetic results of 118 suspected dengue cases from 2017 to 2024. The study evaluated testing methods and examined patients' medical histories. Participants were grouped by age into three categories: youth (≤43 years, n=39), middle-aged (44-63 years, n=25), and elderly (>63 years, n=16). Clinical features and lab outcomes were documented and compared.

Among the 118 suspected dengue cases, 80 serum specimens tested positive for immunoglobulin M (IgM), NS1 antigen, or viral nucleic acid in single or multiple tests. The sensitivity and specificity of the NS1 assay (colloidal gold) compared to real-time PCR (RT-PCR) were 83.78% (62/74) and 33.33% (2/6), respectively. ROC analysis showed AUCs of 0.931 for NS1, 0.963 for RT-PCR, and 0.894 for NS1 + RT-PCR. Both NS1 antigen and nucleic acid detection rates were high during early (1-3 days) and middle (4-14 days) infection stages. Clinical symptom analysis revealed significant differences between the three groups in fatigue, vomiting, abdominal pain, and diarrhea (all P<0.05). Youth had less fatigue but more vomiting and abdominal pain than the middle-aged and elderly (all P<0.05). The middle-aged group experienced more diarrhea (P<0.05). Laboratory results showed significant differences in platelet counts, with the highest platelet counts in the middle-aged group and the lowest in the elderly (P<0.05).

NS1 antigen and dengue virus nucleic acid are highly detectable during early to mid-infection stages. Most young and middle-aged patients show mild symptoms, while the elderly tend to have more severe forms.