Dengue: profile of hematological and biochemical dynamics

Abstract

Aim: The objective of this study was to correlate laboratory tests during the evolution of dengue fever, comparing frequencies between the different clinical forms in order to use test results to predict the severity of the disease.

Methods: This is an observational, descriptive and retrospective study of 154 patients with clinical and serological diagnoses of dengue fever who, in the period from January to May 2008, were admitted in a tertiary state hospital in the city of Fortaleza that is a referral center for infectious diseases. The patients were allocated to two groups according to age: under 15 years old (n = 66) and 15 years or older (n = 88). The tests analyzed were blood count, platelet count, and serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations.

Results: Thrombocytopenia and elevated transaminases were observed in patients with classic dengue fever. The main laboratory abnormalities found in dengue hemorrhagic fever were thrombocytopenia, hemoconcentration and elevated transaminases, similar to severe dengue with the exception of hemoconcentration. Most laboratory abnormalities started on the 3rd day but were more evident on the 5th day with restoration of values by the 11(th) day; this was more prominent in under 15-year-olds and with the more severe clinical forms.

Conclusion: These results are relevant in assessing the disease because they can be used as markers for more severe forms and can help by enabling the adaptation of the therapeutic conduct to the needs of individual patients.

Keywords: Clinical laboratory techniques; Dengue hemorrhagic fever/diagnosis; Dengue virus; Dengue/blood; Hematologic tests; Prognosis.

Figure 1

Distribution of study population according to age (n = 154)

Figure 2

Dynamics of hemoglobin levels in patients with dengue fever according to age group (< 15 years and ≥ 15 years) and clinical form

Figure 3

Dynamics of hematocrit levels in patients with dengue fever according to age group (< 15 years and ≥ 15 years) and clinical form

Figure 4

Dynamics of the overall leukocyte count in patients with dengue fever according to age group (< 15 years and ≥ 15 years) and clinical form

Figure 5

Dynamics of the absolute number of lymphocytes in patients with dengue fever according to age group (< 15 years and ≥ 15 years) and clinical form

Figure 6

Dynamics of platelet count in patients with dengue fever according to age group (< 15 years and ≥ 15 years) and clinical form

Figure 7

Dynamics of serum aspartate aminotransferase in patients with dengue fever according to age group (< 15 years and ≥ 15 years) and clinical form