Unfamiliar hematological parameters predictive of dengue

Abstract

Dengue is an endemic viral disease in India with frequent outbreaks. The clinical manifestations are protean and can vary from persistent fever for few days and minor hematological changes to severe forms which include life threatening complication of dengue shock syndrome. The present study was aimed to identify hematological markers which can aid reflex dengue serology testing for timely diagnosis. Hematological profile of a total of 53 patients with serological diagnosis of dengue was studied. Thrombocytopenia and leucopenia were seen in 32% and 26% of cases respectively. Raised hematocrit was noticed in only two cases. Trend of increase in mean of absolute lymphocyte count was observed on correlation of hematologcial values with duration of fever. Similarly, a dip in mean for absolute neutrophil count in patients with fever of 4 – 6 days duration was noticed. Hematology analyzer XN-550 showed “atypical lymphocyte” as the most common leucocyte flag amongst study group. The present study showed that classical hematological abnormalities of dengue such as thrombocytopenia and raised hematocrit in dengue are present in low frequency. The other findings such as rising absolute lymphocyte counts with duration of fever, low neutrophil counts in fever of 4  to 6 days duration, reactive lymphocytes and peripheral smear, abnormal flags of “atypical lymphocyte” and “blasts” shall be referred for dengue serology testing.