Abdominal Sonographic Findings and Their Association With Thrombocytopenia in Dengue Fever: A Cross-Sectional Study From an Endemic Region

Dengue fever is a major public health concern in endemic regions, with a wide clinical spectrum ranging from mild illness to severe dengue hemorrhagic fever characterized by plasma leakage, bleeding, and organ involvement. Early identification of patients at risk of progression to severe disease remains a clinical challenge, particularly in resource-limited settings where advanced diagnostic tools may not be readily available.

Abdominal ultrasonography has emerged as a useful, non-invasive imaging modality for detecting early signs of plasma leakage and organ involvement in dengue infection. Findings such as gallbladder wall thickening, ascites, pleural effusion, hepatomegaly, and splenomegaly have been reported to correlate with disease severity. However, data on the utility of these sonographic features in Sudanese populations remain limited.

This study was designed as a retrospective cross-sectional analysis conducted in Kassala, Sudan, covering the period from July 2024 to February 2025. It utilized archived abdominal ultrasound images and corresponding clinical and laboratory data of patients with NS1-confirmed dengue infection. The study focused on systematically evaluating predefined sonographic parameters and examining their relationship with hematological indicators, particularly platelet count as a marker of disease severity.

Statistical analysis was performed to determine the strength of associations between imaging findings and clinical severity indicators. Special attention was given to identifying imaging patterns that may serve as early predictors of severe disease, as well as documenting less common but clinically significant complications.

The findings of this study are intended to contribute to the existing body of evidence supporting the role of abdominal ultrasound in dengue management. By clarifying its prognostic value, the study aims to inform clinical practice and encourage the incorporation of ultrasound into routine assessment and risk stratification protocols in dengue-endemic and resource-constrained settings.

Inclusion criteria

• Patients with laboratory-confirmed dengue infection (NS1 positive)
• Patients who underwent abdominal ultrasonography during the course of illness
• Availability of complete clinical, laboratory (including platelet count), and ultrasound data
• Patients of all age groups and both sexes

Exclusion criteria

• Patients without confirmed dengue diagnosis
• Patients with incomplete or missing clinical, laboratory, or ultrasound records
• Patients with pre-existing hepatic, hematologic, or abdominal conditions that may affect ultrasound findings (e.g., chronic liver disease, malignancy)
• Poor-quality or non-interpretable ultrasound images