Hematological changes in infectious diseases. Hematological consequences of viral infections (1)

A number of distinct hematological alterations take place in the presence of infectious diseases. This review seeks to provide a diagnostic guide and prognostic criteria for the clinician in the light of the concomitant hematological changes occurring in the course of acute and chronic viral, bacterial, spirochetal and protozoal infections. The authors emphasize the fact that although certain broad principles may be applied to each type of infection, these principles may have to be interpreted with considerable latitude in any individual case, on account of the variable factors of virulence and resistance. The careful examination of blood films and bone marrow smears, supplemented when appropriate by cytochemical reactions, may be useful in the differential diagnosis of various infective states and in assessing both the severity of the pathological condition and the response of the patient.