RESUMO
BACKGROUND: Oncology patients are at particular risk for parvovirus B19 infection, which may cause severe, persistent, usually nonspecific illness in this group. AIM: This study was designed to assess the prevalence and impact of parvovirus B19 in pediatric oncology patients receiving chemotherapy, and to define the optimal diagnostic tests in such patients. SUBJECTS AND METHODS: Fifty-nine children under chemotherapy (39 with acute lymphocytic leukemia and 20 with solid tumors) with mean age of 4.96+/-1.94 years, in addition to 30 healthy children of matched age and sex, were enrolled in this study. Clinical and laboratory data were collected by examination and from patients' records. Specific parvovirus B19 immunoglobulin (Ig) M and IgG antibodies were assessed by enzyme-linked immunosorbent assay, and parvovirus DNA was detected by nested polymerase chain reaction (PCR) for all patients and controls. RESULTS: Parvovirus DNA was detected in 16 (27.1%), IgM in 3 (5.1%), and IgG in 36 (61%) patients. IgM had sensitivity, specificity, and accuracy of 18.75%, 100%, and 77.9%, respectively, whereas those of IgG were 81.25%, 53.4%, and 61%, respectively. PCR-positive patients had significantly higher frequency of unexplained anemia, red blood cell transfusions, and longer hospital stay than PCR-negative patients (P<0.001). Multiple linear regression analysis showed that unexplained anemia and multiple red blood cell transfusions were the most important variables that can predict PCR positivity. CONCLUSIONS: Parvovirus B19 is not an uncommon problem in pediatric oncology patients who exhibited weak antibody response and nonspecific clinical features. Screening of these patients with PCR rather than serology is recommended when infection is suspected.