The prevalence of human parvovirus B19 infection in children with a variety of hematological disorders

Background: Human parvovirus B19 is a global and common infectious pathogen in humans, particularly in children. The aim of the study: The aim of the study was to compare the prevalence of human parvovirus B19 in children with a variety of hematological disorders with that in normal controls and to highlight the relationship between humoral immune response and the presence of viremia. Methods: This study included 80 children with different hematological disorders. Ten healthy children matched for age and sex were also included as controls. The patients were classified into four groups: group I included 25 patients with chronic hemolytic anemia not in aplastic crisis; group II included 15 patients with hemolytic anemia in aplastic crisis; group III included 20 acute leukemia patients under chemotherapy; and group IV included 20 patients with newly diagnosed acute leukemia. B19-specific IgM and IgG antibodies were detected in patient sera by enzyme-linked immunosorbent assay, whereas B19 DNA was detected by nested PCR analysis. Results: A higher prevalence of B19-specific markers was found in patients compared with controls. In groups I and III, IgG positivity was the highest (52 and 50%, respectively). In group II, the rate of IgM positivity and viremia was the same (46%), followed by IgG positivity (33.3%). However, in group IV IgM positivity was the highest (35%), followed by IgG positivity (30%) and viremia (15%). Groups II, III, and IV showed a higher prevalence of recent B19 infection (53.3, 40, and 45%, respectively) compared with prior and absent infections, whereas in group I prior infection was the most prevalent (40%). None of the groups showed a significant relationship between B19 DNA and immunoglobulin detection, except group II, in which a significant association between the detection of B19 DNA and IgM existed. All groups of patients with positive markers for recent B19 infection had lower hemoglobin levels and RBC counts compared with controls; they also had reticulocytopenia and lymphocytosis. Conclusion: B19 infection is highly prevalent among children with hematological disorders. B19 must be suspected and screened for in the presence of anemia in those patients with neutropenia and lymphocytosis. The direct detection of DNA by PCR needs to be coupled with serological testing for a more reliable diagnosis of B19 infections.