Parvovirus B19 infection The infectious agent most commonly associated with acquired red cell aplasia. (also hepatitis ABC, EBV and HIV).
Erythema infectiosum (fifth disease, slapped cheek)
Parvovirus infection = temp cessation of RBC. For normal healthy children this is usually insignificant. (parvovirus replicates specifically in erythroid progenitor cells with P antigen receptor - not everyone expresses P antigen receptor so some are resistant to virus)
But, basically NOT A PROBLEM UNLESS YOU HAVE ABNORMAL RBC TURNOVER. i.e.haemolytic anaemias (sickle cell, thalassaemia, pyruvate kinase deficiency, autoimmune etc) >> precipitates aplastic erythroblastopaenic crisis