The Use of Simple Laboratory Parameters in the Differential Diagnosis of Acute-Phase Zika and Dengue Viruses.

Background: Differential diagnosis between acute-phase Zika and dengue is challenging because of a similar clinical presentation and the lack of available molecular diagnosis tools in most of endemic areas.

Objectives: Our study aimed to evaluate the use of simple laboratory parameters to differentiate these infections.

Methods: We retrospectively compared simple hematology and biochemistry values in 81 and 341 patients with confirmed Zika and dengue, respectively, collected from June 2013 to March 2014 during the French Polynesia outbreaks.

Results: Thrombocytopenia, neutropenia, leukopenia, lymphopenia, and elevated aspartate aminotransaminases were significantly more frequent in dengue than in Zika (p < 0.001). Platelets <100 × 109/L, neutrophils <0.5 × 109/L, lymphocytes <0.5 × 109/L, and aspartate aminotransaminases >100 IU/mL were found in dengue but not in Zika. The positive predictive value of the -association of leukocytes <4 × 109/L + lymphocytes <1 × 109/L + aspartate aminotransaminases >40 IU/mL for the diagnosis of dengue was 90%, with an accuracy of 82.4%.

Conclusion: For the differential diagnosis between acute-phase Zika and dengue, there is no specific standard laboratory pattern. We identified cutoff values and a combination of laboratory parameters that are a strong argument against Zika and in favor of dengue.