Infectious Mononucleosis, Infectious Lymphocytosis, and Tropical Eoshiophilia.Infectious mononucleosis is usually described with hematologic diseases. It is a febrile disease of probable viral origin, affecting the reticuloendothelial system and producing lymphadenopathy, splenomegaly and an increase of mononuclear cells in the peripheral blood. The leukocyte count may be as high as 40,000 and contain 50 to 90 per cent of large lymphocytes, many of which are atypical and known as Downey cells. A positive test for heterophile antibodies distinguishes this disease from a similar one in children known as infectious lymphocytosis, in which this test is negative. In tropical eosinophilia the white count may be as high as 15,000 with 60 per cent or more eosinophils of the mature type. Many of the patients give a past history of malarial infection and persistent respiratory complaints and at times a low grade fever. There is no demonstrable cause. Recovery occurs without specific treatment.
