摘要:Dengue Fever (DF) is the commonest mosquito-borne viral infection that results in hospitalisation amongst patients in Malaysia. The cornerstone of managing dengue virus infection is the prediction hence prevention of severe DF from developing. Warning signs proposed by WHO as clinical predictors of severe DF are insensitive. Procalcitonin (PCT) has been shown to increase in bacterial infections and is useful in predicting disease severity and mortality. Objective: To determine the level of PCT and other clinical and biochemical parameters associated with severe DF. This is a cross-sectional study conducted over 6 months from September 2017 to February 2018. Patients aged 18 years and above who were hospitalised in Hospital Selayang for a serologically-confirmed DF were recruited. PCT level was taken within 24 h of hospital admission and patients were followed up throughout admission until discharge or death. Out of 133 recruits, 117 (88%) had uncomplicated DF and 16 (12%) had severe DF either with shock (44%) or organ failure (56%). There were 2 (13%) deaths from the severe group. Median PCT levels were higher in severe [0.35 ng/mL (0.15-4.4)] versus non-severe [0.28 ng/mL (0.17-0.54)] DF, however there was no significant difference between both groups ( p = 0.518). Other significant clinical and biochemical factors associated with severe DF were defervescence phase ( p = 0.043), lethargy ( p = 0.000) and albumin <35g/L ( p = 0.015). On multivariate analysis, parameters significantly associated with severe DF include lethargy ( p = 0.001) and albumin <35g/L ( p = 0.009). These two parameters plus PCT of >0.3 ng/mL predict severe DF with a sensitivity of 73% and specificity of 85%. PCT [median 3.6 ng/mL (3.2-4.0)] is also significantly associated with death ( p = 0.021). PCT at a cut-off of >0.3 ng/mL predicts severe DF when combined with lethargy and albumin <35g/L. Furthermore, PCT is significantly associated with death..