Hematologic manifestations of viral infections.

Many infections have an impact on the hematologic system. There also are many noninfectious processes associated with abnormalities of the blood and iatrogenic causes such as pharmacologic therapy that also may affect the marrow or circulating cellular elements. Viral disease may impact on one or more components of blood, and familiarity with these associations can assist in anticipating the course of disease and reducing the need to seek out other etiologies for the usually transient hematologic abnormalities that often occur in patients with viral infections.