Retrospective study on the influence of human parvovirus B19 infection among children with malignant diseases.

Human parvovirus B19 (B19) is a known cause of erythema infectiosum (fifth disease) and aplastic crisis in patients with hemolytic anemias. When patients with malignant diseases are infected by B19 during chemotherapy, erythroid suppression of bone marrow sometimes occurs. We performed a retrospective investigation of B19 infection among 95 children with malignant diseases in our hospital during the past 14 years. By the method of dot blot hybridization, 9 of 95 patients were found to be positive for B19 DNA during chemotherapy. All 9 patients had reticulocytopenia at the time B19 DNA was detected in their serum samples. Neutropenia and thrombocytopenia were not found. Seven of them had only transient reticulocytopenia. Serum samples from 2 other patients were positive for B19 DNA for a longer time. They suffered from persistent anemia for about 2 and 13 month, respectively. The years when B19 DNA was detected from the 9 patients corresponded to the prevalence of erythema infectiosum in Japan.