Comparison of Clinical Features and Haematological Parameters along with C-Reactive Protein and Transaminase Levels to Distinguish Dengue Infection from other Febrile Illnesses that Mimic Dengue.

Abstract

Background: The broad spectrum of clinical manifestations of dengue fever (DF) which mimics other infections, makes it challenging to diagnose it in the early course of disease. Serological tests used in the diagnosis of DF are costly and inaccessible in most hospitals. This study was aimed to identify clinical and laboratory parameters that would help in differentiating DF from other febrile illnesses (OFI). Objective: To compare clinical features, Complete Blood Count (CBC) parameters, C-reactive protein (CRP), and transaminase levels in patients with dengue infection and in patients with OFIs that mimic dengue Method: A retrospective cross-sectional study was conducted from January to October, 2023 including 144 patients aged 18 years and older, admitted with fever to teaching hospital, Karapitiya. The diagnosis of DF (n=82) was confirmed by serology. The control group (n=62) included patients whose serology was negative for DF and diagnosed with acute febrile illnesses (fever < 14 days). Clinical features and laboratory parameters were recorded from 3rd to 9th day of infection for both groups. Results: The study included 82 DF patients and 62 patients with OFIs. Chills and abdominal pain were statistically significant clinical features in patients with OFIs (Chi-square test: p<0.05). Among the CBC parameters, the DF group had significantly lower white blood cell (WBC) count, platelet count and neutrophil to lymphocyte ratio (independent sample t-test; p<0.01). The specific days that had significant differences in the respective parameters of the CBC were also identified. Days 3, 4 and 5 showed significantly low levels of WBC count (p<0.001) in DF patients. Neutrophil-to-lymphocyte ratio and platelet count were significantly low on days 4, 5 and 5, 6, 7, respectively in DF patients (p<0.001). CRP levels were significantly high in OFI patients while transaminase levels showed significantly high levels in DF patients (Mann-Whitney u-test; p<0.001). Conclusion: This study identified several clinical and widely available laboratory variables to distinguish DF from OFIs. Chills and abdominal pain are among the prominent clinical features identified in patients with OFIs. Among the laboratory parameters, low platelet count, low WBC count, and low neutrophil-to-lymphocyte ratio can be considered critical among DF patients. However, the results obtained need better validation upon reaching a higher sample size.