Laboratory confirmation of dengue and chikungunya co-infection

In November 2006, a 70-year old man presented with a history of high fever, severe headache and arthralgia of knees, and small joints of his hands and feet of 3 days’ duration. On examination, the patient had mild swelling of the small joints of hands. There was no skin rash, bleeding into skin or mucosal membranes. His blood analysis showed a leucopenia (WBC 3.04 x 103 per μl) with a relative lymphocytosis (51%). The total platelet count was 115 x 103 per μl. The haemoglobin was 14.3 g / dl with a packed cell volume of 43.8%. The first-hour erythrocyte sedimentation rate, serum alanine transaminase level and urine analysis were normal.